diff --git a/ keystore.propertie b/ keystore.propertie
new file mode 100644
index 0000000..1276c0e
--- /dev/null
+++ b/ keystore.propertie	
@@ -0,0 +1,4 @@
+storeFile=catalogapp-release.jks
+storePassword=prajwal4121998
+keyAlias=catalogapp-key
+keyPassword=prajwal4121998
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..6334d4b
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,190 @@
+name: CatalogApp CI
+
+on:
+  push:
+    branches:
+      - main
+      - develop
+      - 'feature/**'
+      - 'hotfix/**'
+  pull_request:
+    branches:
+      - main
+      - develop
+  workflow_dispatch:
+
+env:
+  GRADLE_OPTS: "-Dorg.gradle.daemon=false -Dorg.gradle.parallel=true -Dkotlin.incremental=false"
+
+jobs:
+  # ── Job 1: Quality Gates ──────────────────────────────────────────────────
+  lint-and-test:
+    name: Lint + Test + Quality Gates
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up JDK 17
+        uses: actions/setup-java@v4
+        with:
+          java-version: '17'
+          distribution: 'temurin'
+          cache: gradle
+
+      - name: Cache Gradle build outputs
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+            ~/.android/build-cache
+          key: gradle-${{ runner.os }}-${{ hashFiles('**/*.gradle.kts', '**/gradle-wrapper.properties', '**/libs.versions.toml') }}
+          restore-keys: |
+            gradle-${{ runner.os }}-
+
+      - name: Grant gradlew permission
+        run: chmod +x gradlew
+
+      - name: Run Android Lint
+        run: ./gradlew lintDevDebug --stacktrace
+
+      - name: Run unit tests
+        run: ./gradlew testDevDebugUnitTest --stacktrace
+
+      - name: Generate JaCoCo coverage report
+        run: ./gradlew jacocoTestReport --stacktrace
+
+      - name: Verify coverage threshold
+        run: ./gradlew jacocoTestCoverageVerification --stacktrace
+
+      - name: Run Detekt
+        run: ./gradlew detekt --stacktrace
+
+      - name: Upload lint report
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: lint-report
+          path: app/build/reports/lint-results-devDebug.html
+          retention-days: 7
+
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: test-results
+          path: '**/build/reports/tests/'
+          retention-days: 7
+
+      - name: Upload coverage report
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: jacoco-coverage-report
+          path: app/build/reports/jacoco/jacocoTestReport/html/
+          retention-days: 7
+
+      - name: Upload Detekt report
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: detekt-report
+          path: '**/build/reports/detekt/detekt.html'
+          retention-days: 7
+
+  # ── Job 2: Build ──────────────────────────────────────────────────────────
+  build:
+    name: Build APK / AAB
+    runs-on: ubuntu-latest
+    needs: lint-and-test
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up JDK 17
+        uses: actions/setup-java@v4
+        with:
+          java-version: '17'
+          distribution: 'temurin'
+          cache: gradle
+
+      - name: Cache Gradle build outputs
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+            ~/.android/build-cache
+          key: gradle-${{ runner.os }}-${{ hashFiles('**/*.gradle.kts', '**/gradle-wrapper.properties', '**/libs.versions.toml') }}
+          restore-keys: |
+            gradle-${{ runner.os }}-
+
+      - name: Grant gradlew permission
+        run: chmod +x gradlew
+
+      - name: Decode keystore
+        if: github.ref_name == 'main' || github.ref_name == 'develop'
+        run: |
+          echo "${{ secrets.KEYSTORE_BASE64 }}" | base64 --decode > ${{ github.workspace }}/catalogapp-release.jks
+          echo "KEYSTORE_FILE=${{ github.workspace }}/catalogapp-release.jks" >> $GITHUB_ENV
+
+      - name: Set signing environment variables
+        if: github.ref_name == 'main' || github.ref_name == 'develop'
+        run: |
+          echo "KEYSTORE_PASSWORD=${{ secrets.KEYSTORE_PASSWORD }}" >> $GITHUB_ENV
+          echo "KEY_ALIAS=${{ secrets.KEY_ALIAS }}" >> $GITHUB_ENV
+          echo "KEY_PASSWORD=${{ secrets.KEY_PASSWORD }}" >> $GITHUB_ENV
+
+      - name: Build Dev Debug APK (feature branches)
+        if: github.ref_name != 'develop' && github.ref_name != 'main'
+        run: ./gradlew assembleDevDebug --stacktrace
+
+      - name: Build Staging Debug APK (develop)
+        if: github.ref_name == 'develop'
+        run: ./gradlew assembleStagingDebug --stacktrace
+
+      - name: Build Prod Release AAB (main)
+        if: github.ref_name == 'main'
+        run: ./gradlew bundleProdRelease --stacktrace
+
+      - name: Upload Dev APK
+        if: github.ref_name != 'develop' && github.ref_name != 'main'
+        uses: actions/upload-artifact@v4
+        with:
+          name: dev-debug-apk-${{ github.run_number }}
+          path: app/build/outputs/apk/dev/debug/*.apk
+          retention-days: 7
+
+      - name: Upload Staging APK
+        if: github.ref_name == 'develop'
+        uses: actions/upload-artifact@v4
+        with:
+          name: staging-debug-apk-${{ github.run_number }}
+          path: app/build/outputs/apk/staging/debug/*.apk
+          retention-days: 1
+
+      - name: Upload Prod AAB
+        if: github.ref_name == 'main'
+        uses: actions/upload-artifact@v4
+        with:
+          name: prod-release-aab-${{ github.run_number }}
+          path: app/build/outputs/bundle/prodRelease/*.aab
+          retention-days: 1
+
+      - name: Clean up keystore
+        if: always()
+        run: rm -f ${{ github.workspace }}/catalogapp-release.jks
+
+  # ── Job 3: Deploy ─────────────────────────────────────────────────────────
+  deploy:
+    name: Deploy (Module 6 - pending UI)
+    runs-on: ubuntu-latest
+    needs: build
+    if: github.ref_name == 'develop' || github.ref_name == 'main'
+
+    steps:
+      - name: Deploy placeholder
+        run: echo "Firebase App Distribution configured in Module 6 after first UI screen"
diff --git a/.gitignore b/.gitignore
index ebece43..ac48044 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,32 +1,45 @@
 # Built outputs
-/build
-app/build
-core/*/build
-data/*/build
-domain/*/build
-feature/*/build
-
-# Gradle
-.gradle
-gradle/wrapper/gradle-wrapper.jar
+*.apk
+*.aab
+*.ap_
+*.dex
+
+# Build folders
+build/
+app/build/
+**/build/
+
+# Gradle cache and wrapper
+.gradle/
+!gradle/wrapper/gradle-wrapper.jar
+!gradle/wrapper/gradle-wrapper.properties
+
+# Local configuration
 local.properties
+keystore.properties
 
-# Android Studio / IntelliJ
-.idea/
+# Android Studio IDE files
 *.iml
-*.iws
-*.ipr
-captures/
-.externalNativeBuild/
-.cxx/
-*.DS_Store
+.idea/
+.idea/workspace.xml
+.idea/tasks.xml
+.idea/gradle.xml
+.idea/assetWizardSettings.xml
+.idea/dictionaries
+.idea/libraries
+.idea/caches
+.idea/modules.xml
+.DS_Store
 
-# Keystore — NEVER commit this
+# Signing files — NEVER commit
 *.jks
 *.keystore
 
-# Google Services (if added later)
-google-services.json
+# Navigation editor temp files
+.navigation/
+
+# Captures
+captures/
 
-# Secrets
-secrets.properties
+# Test results
+/app/test-results/
diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index 1d82639..cf492bc 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -1,10 +1,36 @@
+import java.util.Properties
+
 plugins {
     alias(libs.plugins.android.application)
     alias(libs.plugins.kotlin.compose)
     alias(libs.plugins.hilt)
     alias(libs.plugins.ksp)
+    alias(libs.plugins.detekt)
+    alias(libs.plugins.kotlin.serialization)
+    jacoco
+}
+
+// ─── Keystore properties ──────────────────────────────────────────────────────
+// Reads from keystore.properties locally, falls back to env vars on CI
+// keystore.properties is in .gitignore — never committed
+val keystorePropertiesFile = rootProject.file("keystore.properties")
+val keystoreProperties = Properties()
+if (keystorePropertiesFile.exists()) {
+    keystoreProperties.load(keystorePropertiesFile.inputStream())
 }
 
+fun signingProp(envVar: String, propKey: String): String? =
+    System.getenv(envVar) ?: keystoreProperties.getProperty(propKey)
+
+val canSign = listOf(
+    signingProp("KEYSTORE_FILE", "storeFile"),
+    signingProp("KEYSTORE_PASSWORD", "storePassword"),
+    signingProp("KEY_ALIAS", "keyAlias"),
+    signingProp("KEY_PASSWORD", "keyPassword")
+).all { it != null }
+// ─────────────────────────────────────────────────────────────────────────────
+
+
 android {
     namespace = "com.example.catalogapp"
     compileSdk {
@@ -17,15 +43,68 @@ android {
         applicationId = "com.example.catalogapp"
         minSdk = 24
         targetSdk = 36
-        versionCode = 1
-        versionName = "1.0"
+
+        // versionCode auto-increments from CI run number
+        // Locally: always 1. On CI: run 1 → versionCode 1, run 47 → versionCode 47
+        versionCode = System.getenv("GITHUB_RUN_NUMBER")?.toInt() ?: 1
+        versionName = "1.0.${System.getenv("GITHUB_RUN_NUMBER") ?: "0"}"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }
 
+    // ─── Signing configs ──────────────────────────────────────────────────────
+    signingConfigs {
+        if (canSign) {
+            create("release") {
+                storeFile = file(signingProp("KEYSTORE_FILE", "storeFile")!!)
+                storePassword = signingProp("KEYSTORE_PASSWORD", "storePassword")!!
+                keyAlias = signingProp("KEY_ALIAS", "keyAlias")!!
+                keyPassword = signingProp("KEY_PASSWORD", "keyPassword")!!
+            }
+        }
+    }
+    // ─────────────────────────────────────────────────────────────────────────
+
+    // ─── Flavors ──────────────────────────────────────────────────────────────
+    flavorDimensions += "environment"
+
+    productFlavors {
+        create("dev") {
+            dimension = "environment"
+            applicationIdSuffix = ".dev"
+            versionNameSuffix = "-dev"
+            buildConfigField("String", "BASE_URL", "\"https://fakestoreapi.com/\"")
+            buildConfigField("Boolean", "ENABLE_LOGGING", "true")
+        }
+        create("staging") {
+            dimension = "environment"
+            applicationIdSuffix = ".staging"
+            versionNameSuffix = "-staging"
+            buildConfigField("String", "BASE_URL", "\"https://fakestoreapi.com/\"")
+            buildConfigField("Boolean", "ENABLE_LOGGING", "true")
+        }
+        create("prod") {
+            dimension = "environment"
+            // No suffix — this is the real app
+            buildConfigField("String", "BASE_URL", "\"https://fakestoreapi.com/\"")
+            buildConfigField("Boolean", "ENABLE_LOGGING", "false")
+        }
+    }
+    // ─────────────────────────────────────────────────────────────────────────
+
     buildTypes {
-        release {
+        debug {
+            applicationIdSuffix = ".debug"
+            versionNameSuffix = "-debug"
             isMinifyEnabled = false
+            isDebuggable = true
+            enableUnitTestCoverage = true
+        }
+        release {
+            isMinifyEnabled = true
+            isShrinkResources = true
+            isDebuggable = false
+            signingConfig = if (canSign) signingConfigs.findByName("release") else null
             proguardFiles(
                 getDefaultProguardFile("proguard-android-optimize.txt"),
                 "proguard-rules.pro"
@@ -38,6 +117,7 @@ android {
     }
     buildFeatures {
         compose = true
+        buildConfig = true
     }
 }
 
@@ -52,6 +132,17 @@ dependencies {
     implementation(libs.androidx.compose.material3)
     implementation(libs.hilt.android)
     ksp(libs.hilt.compiler)
+    implementation(project(":data:product"))
+    implementation(project(":core:designsystem"))
+    implementation(project(":feature:catalog"))
+    implementation(project(":feature:detail"))
+    implementation(project(":feature:search"))
+    implementation(libs.androidx.navigation.compose)
+    implementation(libs.hilt.navigation.compose)
+    implementation(libs.kotlinx.serialization.json)
+    implementation(libs.androidx.work.runtime.ktx)
+    implementation(libs.hilt.work)
+    ksp(libs.hilt.work.compiler)
     testImplementation(libs.junit)
     androidTestImplementation(libs.androidx.junit)
     androidTestImplementation(libs.androidx.espresso.core)
@@ -60,3 +151,342 @@ dependencies {
     debugImplementation(libs.androidx.compose.ui.tooling)
     debugImplementation(libs.androidx.compose.ui.test.manifest)
 }
+
+// ─── JaCoCo configuration ─────────────────────────────────────────────────────
+jacoco {
+    toolVersion = "0.8.12"
+}
+
+// Enable coverage data collection during unit tests
+tasks.withType<Test> {
+    configure<JacocoTaskExtension> {
+        isIncludeNoLocationClasses = true
+        excludes = listOf("jdk.internal.*")
+    }
+    testLogging {
+        events("passed", "skipped", "failed")
+        showStandardStreams = true
+        exceptionFormat = org.gradle.api.tasks.testing.logging.TestExceptionFormat.FULL
+    }
+}
+
+// ─── JaCoCo report task ───────────────────────────────────────────────────────
+tasks.register<JacocoReport>("jacocoTestReport") {
+    dependsOn(
+        "testDevDebugUnitTest",
+        ":domain:product:test",
+        ":core:common:test",
+        ":data:product:testDebugUnitTest",
+        ":feature:catalog:testDebugUnitTest",
+        ":feature:detail:testDebugUnitTest",
+        ":feature:search:testDebugUnitTest"
+    )
+
+    reports {
+        xml.required.set(true)
+        html.required.set(true)
+    }
+
+    val fileFilter = listOf(
+        "**/R.class", "**/R\$*.class", "**/BuildConfig.*",
+        "**/Manifest*.*", "**/*Test*.*", "android/**/*.*",
+        "**/*Hilt*.*", "**/*Dagger*.*", "**/*_Factory*.*",
+        "**/*MembersInjector*.*", "**/di/**",
+        "**/hilt_aggregated_deps/**",
+        "**/dagger/hilt/**",
+        "**/*Database*.*",
+        "**/*Database_Impl*.*",
+        // Exclude Kotlin compiler-generated lambda/coroutine synthetic classes
+        "**/*\$*\$*.*",
+        "**/*\$inlined*.*",
+        // Compose UI — requires instrumented tests, not JUnit
+        // Covered separately via androidTest ComposeTestRule
+        "**/ui/**",
+        "**/*Screen*.*",
+        "**/*Content*.*",
+        "**/*composable*.*",
+        // Feature module components — pure Compose, no unit testable logic
+        "**/components/**"
+    )
+
+    val appTree = fileTree(layout.buildDirectory.get()) {
+        include(
+            "tmp/kotlin-classes/devDebug/**/*.class",
+            "intermediates/javac/devDebug/**/*.class"
+        )
+        exclude(fileFilter)
+    }
+
+    val domainTree = fileTree(project(":domain:product").layout.buildDirectory.get()) {
+        include("classes/kotlin/main/**/*.class")
+        exclude(fileFilter)
+    }
+
+    val coreCommonTree = fileTree(project(":core:common").layout.buildDirectory.get()) {
+        include("classes/kotlin/main/**/*.class")
+        exclude(fileFilter)
+    }
+
+    val dataTree = fileTree(project(":data:product").layout.buildDirectory.get()) {
+        include("intermediates/built_in_kotlinc/debug/compileDebugKotlin/classes/**/*.class")
+        exclude(fileFilter)
+    }
+
+    val catalogTree = fileTree(project(":feature:catalog").layout.buildDirectory.get()) {
+        include("intermediates/built_in_kotlinc/debug/compileDebugKotlin/classes/**/*.class")
+        exclude(fileFilter)
+    }
+
+    val detailTree = fileTree(project(":feature:detail").layout.buildDirectory.get()) {
+        include("intermediates/built_in_kotlinc/debug/compileDebugKotlin/classes/**/*.class")
+        exclude(fileFilter)
+    }
+
+    val searchTree = fileTree(project(":feature:search").layout.buildDirectory.get()) {
+        include("intermediates/built_in_kotlinc/debug/compileDebugKotlin/classes/**/*.class")
+        exclude(fileFilter)
+    }
+
+    sourceDirectories.setFrom(
+        files(
+            "src/main/java",
+            "${project(":domain:product").projectDir}/src/main/java",
+            "${project(":core:common").projectDir}/src/main/java",
+            "${project(":data:product").projectDir}/src/main/java",
+            "${project(":feature:catalog").projectDir}/src/main/java",
+            "${project(":feature:detail").projectDir}/src/main/java",
+            "${project(":feature:search").projectDir}/src/main/java"
+        )
+    )
+
+    classDirectories.setFrom(
+        files(
+            appTree,
+            domainTree,
+            coreCommonTree,
+            dataTree,
+            catalogTree,
+            detailTree,
+            searchTree
+        )
+    )
+
+    executionData.setFrom(
+        files(
+            fileTree(layout.buildDirectory.get()) {
+                include("outputs/unit_test_code_coverage/devDebugUnitTest/testDevDebugUnitTest.exec")
+            },
+            fileTree(project(":domain:product").layout.buildDirectory.get()) {
+                include("jacoco/test.exec")
+            },
+            fileTree(project(":core:common").layout.buildDirectory.get()) {
+                include("jacoco/test.exec")
+            },
+            fileTree(project(":data:product").layout.buildDirectory.get()) {
+                include("jacoco/testDebugUnitTest.exec")
+            },
+            fileTree(project(":feature:catalog").layout.buildDirectory.get()) {
+                include("jacoco/testDebugUnitTest.exec")
+            },
+            fileTree(project(":feature:detail").layout.buildDirectory.get()) {
+                include("jacoco/testDebugUnitTest.exec")
+            },
+            fileTree(project(":feature:search").layout.buildDirectory.get()) {
+                include("jacoco/testDebugUnitTest.exec")
+            }
+        )
+    )
+}
+
+// ─── Coverage threshold enforcement ───────────────────────────────────────────
+tasks.register<JacocoCoverageVerification>("jacocoTestCoverageVerification") {
+    dependsOn("jacocoTestReport")
+
+    violationRules {
+        // Overall app threshold — excludes generated/untestable code via fileFilter
+        rule {
+            limit {
+                minimum = "0.55".toBigDecimal()
+            }
+        }
+
+        // Domain layer — pure business logic, highest bar
+        rule {
+            element = "CLASS"
+            includes = listOf("com.example.catalogapp.domain.*")
+            limit {
+                minimum = "0.70".toBigDecimal()
+            }
+        }
+
+        // Repository — critical class, must test error paths
+        rule {
+            element = "CLASS"
+            includes = listOf("com.example.catalogapp.data.product.repository.*")
+            limit {
+                minimum = "0.70".toBigDecimal()
+            }
+        }
+
+        // Mapper — simple pure functions, high bar achievable
+        rule {
+            element = "CLASS"
+            includes = listOf("com.example.catalogapp.data.product.mapper.*")
+            limit {
+                minimum = "0.85".toBigDecimal()
+            }
+        }
+
+        rule {
+            element = "CLASS"
+            includes = listOf("com.example.catalogapp.feature.catalog.*ViewModel*")
+            limit {
+                minimum = "0.75".toBigDecimal()
+            }
+        }
+
+        rule {
+            element = "CLASS"
+            includes = listOf("com.example.catalogapp.feature.detail.*ViewModel*")
+            limit {
+                minimum = "0.75".toBigDecimal()
+            }
+        }
+
+        rule {
+            element = "CLASS"
+            includes = listOf("com.example.catalogapp.feature.search.*ViewModel*")
+            limit {
+                minimum = "0.75".toBigDecimal()
+            }
+        }
+    }
+
+    val fileFilter = listOf(
+        "**/R.class", "**/R\$*.class", "**/BuildConfig.*",
+        "**/Manifest*.*", "**/*Test*.*", "android/**/*.*",
+        "**/*Hilt*.*", "**/*Dagger*.*", "**/*_Factory*.*",
+        "**/hilt_aggregated_deps/**",
+        "**/dagger/hilt/**",
+        "**/dao/**",
+        "**/*Database*.*",
+        "**/*Database_Impl*.*",
+        // Exclude Kotlin compiler-generated lambda/coroutine synthetic classes
+        "**/*\$*\$*.*",
+        "**/*\$inlined*.*",
+        // Compose UI — requires instrumented tests, not JUnit
+        // Covered separately via androidTest ComposeTestRule
+        "**/ui/**",
+        "**/*Screen*.*",
+        "**/*Content*.*",
+        "**/*composable*.*",
+        // Feature module components — pure Compose, no unit testable logic
+        "**/components/**"
+    )
+
+    // Collect classes from all modules
+    val appTree = fileTree(layout.buildDirectory.get()) {
+        include(
+            "tmp/kotlin-classes/devDebug/**/*.class",
+            "intermediates/javac/devDebug/**/*.class"
+        )
+        exclude(fileFilter)
+    }
+
+    val domainTree = fileTree(project(":domain:product").layout.buildDirectory.get()) {
+        include("classes/kotlin/main/**/*.class")
+        exclude(fileFilter)
+    }
+
+    val coreCommonTree = fileTree(project(":core:common").layout.buildDirectory.get()) {
+        include("classes/kotlin/main/**/*.class")
+        exclude(fileFilter)
+    }
+
+    val dataTree = fileTree(project(":data:product").layout.buildDirectory.get()) {
+        include("intermediates/built_in_kotlinc/debug/compileDebugKotlin/classes/**/*.class")
+        exclude(fileFilter)
+    }
+
+    val catalogTree = fileTree(project(":feature:catalog").layout.buildDirectory.get()) {
+        include("intermediates/built_in_kotlinc/debug/compileDebugKotlin/classes/**/*.class")
+        exclude(fileFilter)
+    }
+
+    val detailTree = fileTree(project(":feature:detail").layout.buildDirectory.get()) {
+        include("intermediates/built_in_kotlinc/debug/compileDebugKotlin/classes/**/*.class")
+        exclude(fileFilter)
+    }
+
+    val searchTree = fileTree(project(":feature:search").layout.buildDirectory.get()) {
+        include("intermediates/built_in_kotlinc/debug/compileDebugKotlin/classes/**/*.class")
+        exclude(fileFilter)
+    }
+
+    sourceDirectories.setFrom(
+        files(
+            "src/main/java",
+            "${project(":domain:product").projectDir}/src/main/java",
+            "${project(":core:common").projectDir}/src/main/java",
+            "${project(":data:product").projectDir}/src/main/java",
+            "${project(":feature:catalog").projectDir}/src/main/java",
+            "${project(":feature:detail").projectDir}/src/main/java",
+            "${project(":feature:search").projectDir}/src/main/java"
+        )
+    )
+
+    classDirectories.setFrom(
+        files(
+            appTree,
+            domainTree,
+            coreCommonTree,
+            dataTree,
+            catalogTree,
+            detailTree,
+            searchTree
+        )
+    )
+
+    executionData.setFrom(
+        files(
+            fileTree(layout.buildDirectory.get()) {
+                include("outputs/unit_test_code_coverage/devDebugUnitTest/testDevDebugUnitTest.exec")
+            },
+            fileTree(project(":domain:product").layout.buildDirectory.get()) {
+                include("jacoco/test.exec")
+            },
+            fileTree(project(":core:common").layout.buildDirectory.get()) {
+                include("jacoco/test.exec")
+            },
+            fileTree(project(":data:product").layout.buildDirectory.get()) {
+                include("jacoco/testDebugUnitTest.exec")
+            },
+            fileTree(project(":feature:catalog").layout.buildDirectory.get()) {
+                include("jacoco/testDebugUnitTest.exec")
+            },
+            fileTree(project(":feature:detail").layout.buildDirectory.get()) {
+                include("jacoco/testDebugUnitTest.exec")
+            },
+            fileTree(project(":feature:search").layout.buildDirectory.get()) {
+                include("jacoco/testDebugUnitTest.exec")
+            }
+        )
+    )
+}
+
+// ─── Detekt configuration ──────────────────────────────────────────────────
+detekt {
+    config.setFrom(files("$rootDir/config/detekt/detekt.yml"))
+    buildUponDefaultConfig = true
+    autoCorrect = false
+    source.setFrom("src/main/java", "src/main/kotlin")
+}
+
+tasks.withType<io.gitlab.arturbosch.detekt.Detekt>().configureEach {
+    reports {
+        html.required.set(true)
+        xml.required.set(true)
+        txt.required.set(false)
+        sarif.required.set(false)
+    }
+}
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index a405a76..fc63dcd 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -15,7 +15,6 @@
         <activity
             android:name=".MainActivity"
             android:exported="true"
-            android:label="@string/app_name"
             android:theme="@style/Theme.CatalogApp">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
@@ -23,6 +22,16 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+        <provider
+            android:name="androidx.startup.InitializationProvider"
+            android:authorities="${applicationId}.androidx-startup"
+            android:exported="false"
+            tools:node="merge">
+            <meta-data
+                android:name="androidx.work.WorkManagerInitializer"
+                android:value="androidx.startup.InitializationProvider"
+                tools:node="remove" />
+        </provider>
     </application>
 
 </manifest>
diff --git a/app/src/main/java/com/example/catalogapp/CatalogApplication.kt b/app/src/main/java/com/example/catalogapp/CatalogApplication.kt
index 89275aa..7a0be34 100644
--- a/app/src/main/java/com/example/catalogapp/CatalogApplication.kt
+++ b/app/src/main/java/com/example/catalogapp/CatalogApplication.kt
@@ -1,7 +1,28 @@
 package com.example.catalogapp
 
 import android.app.Application
+import androidx.hilt.work.HiltWorkerFactory
+import androidx.work.Configuration
+import com.example.catalogapp.data.product.sync.SyncScheduler
 import dagger.hilt.android.HiltAndroidApp
+import javax.inject.Inject
 
 @HiltAndroidApp
-class CatalogApplication : Application()
+class CatalogApplication : Application(), Configuration.Provider {
+
+    @Inject
+    lateinit var workerFactory: HiltWorkerFactory
+
+    @Inject
+    lateinit var syncScheduler: SyncScheduler
+
+    override val workManagerConfiguration: Configuration
+        get() = Configuration.Builder()
+            .setWorkerFactory(workerFactory)
+            .build()
+
+    override fun onCreate() {
+        super.onCreate()
+        syncScheduler.schedulePeriodicSync()
+    }
+}
diff --git a/app/src/main/java/com/example/catalogapp/MainActivity.kt b/app/src/main/java/com/example/catalogapp/MainActivity.kt
index 2153785..eb923ba 100644
--- a/app/src/main/java/com/example/catalogapp/MainActivity.kt
+++ b/app/src/main/java/com/example/catalogapp/MainActivity.kt
@@ -4,14 +4,8 @@ import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
-import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.layout.padding
-import androidx.compose.material3.Scaffold
-import androidx.compose.material3.Text
-import androidx.compose.runtime.Composable
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.tooling.preview.Preview
-import com.example.catalogapp.ui.theme.CatalogAppTheme
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+import com.example.catalogapp.navigation.CatalogNavHost
 import dagger.hilt.android.AndroidEntryPoint
 
 @AndroidEntryPoint
@@ -21,30 +15,10 @@ class MainActivity : ComponentActivity() {
         enableEdgeToEdge()
 
         setContent {
-            CatalogAppTheme {
-                Scaffold(modifier = Modifier.fillMaxSize()) { innerPadding ->
-                    Greeting(
-                        name = "Android",
-                        modifier = Modifier.padding(innerPadding)
-                    )
-                }
+            CatalogTheme {
+//                Scaffold(modifier = Modifier.fillMaxSize()) { innerPadding -> }
+                CatalogNavHost()
             }
         }
     }
 }
-
-@Composable
-fun Greeting(name: String, modifier: Modifier = Modifier) {
-    Text(
-        text = "Hello $name!",
-        modifier = modifier
-    )
-}
-
-@Preview(showBackground = true)
-@Composable
-fun GreetingPreview() {
-    CatalogAppTheme {
-        Greeting("Android")
-    }
-}
diff --git a/app/src/main/java/com/example/catalogapp/navigation/CatalogNavHost.kt b/app/src/main/java/com/example/catalogapp/navigation/CatalogNavHost.kt
new file mode 100644
index 0000000..ad15f1a
--- /dev/null
+++ b/app/src/main/java/com/example/catalogapp/navigation/CatalogNavHost.kt
@@ -0,0 +1,84 @@
+package com.example.catalogapp.navigation
+
+import androidx.compose.animation.core.tween
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+import androidx.compose.animation.slideInHorizontally
+import androidx.compose.animation.slideOutHorizontally
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.navigation.NavHostController
+import androidx.navigation.compose.NavHost
+import androidx.navigation.compose.composable
+import androidx.navigation.compose.rememberNavController
+import androidx.navigation.toRoute
+import com.example.catalogapp.feature.catalog.CatalogScreen
+import com.example.catalogapp.feature.detail.DetailScreen
+import com.example.catalogapp.feature.search.SearchScreen
+
+private const val NAV_TRANSITION_DURATION_MS = 250
+
+@Composable
+fun CatalogNavHost(
+    navController: NavHostController = rememberNavController()
+) {
+    Surface(
+        modifier = Modifier,
+        color = MaterialTheme.colorScheme.background
+    ) {
+        NavHost(
+            navController = navController,
+            startDestination = CatalogRoute,
+            enterTransition = {
+                slideInHorizontally(
+                    animationSpec = tween(NAV_TRANSITION_DURATION_MS)
+                ) { fullWidth -> fullWidth } + fadeIn(tween(NAV_TRANSITION_DURATION_MS))
+            },
+            exitTransition = {
+                slideOutHorizontally(
+                    animationSpec = tween(NAV_TRANSITION_DURATION_MS)
+                ) { fullWidth -> -fullWidth } + fadeOut(tween(NAV_TRANSITION_DURATION_MS))
+            },
+            popEnterTransition = {
+                slideInHorizontally(
+                    animationSpec = tween(NAV_TRANSITION_DURATION_MS)
+                ) { fullWidth -> -fullWidth } + fadeIn(tween(NAV_TRANSITION_DURATION_MS))
+            },
+            popExitTransition = {
+                slideOutHorizontally(
+                    animationSpec = tween(NAV_TRANSITION_DURATION_MS)
+                ) { fullWidth -> fullWidth } + fadeOut(tween(NAV_TRANSITION_DURATION_MS))
+            }
+        ) {
+            composable<CatalogRoute> {
+                CatalogScreen(
+                    onNavigateToDetail = { productId ->
+                        navController.navigateSafely(DetailRoute(productId))
+                    },
+                    onNavigateToSearch = {
+                        navController.navigateSafely(SearchRoute)
+                    }
+                )
+            }
+
+            composable<DetailRoute> { backStackEntry ->
+                val route = backStackEntry.toRoute<DetailRoute>()
+                DetailScreen(
+                    productId = route.productId,
+                    onNavigateBack = { navController.popBackStackSafely() }
+                )
+            }
+
+            composable<SearchRoute> {
+                SearchScreen(
+                    onNavigateToDetail = { productId ->
+                        navController.navigateSafely(DetailRoute(productId))
+                    }
+                )
+            }
+        }
+    }
+}
+
diff --git a/app/src/main/java/com/example/catalogapp/navigation/Routes.kt b/app/src/main/java/com/example/catalogapp/navigation/Routes.kt
new file mode 100644
index 0000000..23ab35d
--- /dev/null
+++ b/app/src/main/java/com/example/catalogapp/navigation/Routes.kt
@@ -0,0 +1,17 @@
+package com.example.catalogapp.navigation
+
+import kotlinx.serialization.Serializable
+
+// ─── Type-safe route definitions ──────────────────────────────────────────────
+// Each route is a @Serializable class/object — Navigation generates
+// the route string automatically, no manual string formatting needed.
+// Compile-time safety: wrong argument types fail at build time, not runtime.
+
+@Serializable
+object CatalogRoute
+
+@Serializable
+data class DetailRoute(val productId: Int)
+
+@Serializable
+object SearchRoute
diff --git a/app/src/main/java/com/example/catalogapp/navigation/SafeNavigate.kt b/app/src/main/java/com/example/catalogapp/navigation/SafeNavigate.kt
new file mode 100644
index 0000000..a80054a
--- /dev/null
+++ b/app/src/main/java/com/example/catalogapp/navigation/SafeNavigate.kt
@@ -0,0 +1,24 @@
+package com.example.catalogapp.navigation
+
+import androidx.lifecycle.Lifecycle
+import androidx.navigation.NavController
+
+/**
+ * Prevents duplicate navigation calls from rapid double-taps or multiple
+ * simultaneous triggers (e.g. two different buttons both calling navigate()
+ * before the first transition settles). Only allows navigation when the
+ * current back stack entry is RESUMED — i.e. no transition is in flight.
+ */
+fun NavController.navigateSafely(route: Any) {
+    if (currentBackStackEntry?.lifecycle?.currentState == Lifecycle.State.RESUMED) {
+        navigate(route)
+    }
+}
+
+fun NavController.popBackStackSafely(): Boolean {
+    return if (currentBackStackEntry?.lifecycle?.currentState == Lifecycle.State.RESUMED) {
+        popBackStack()
+    } else {
+        false
+    }
+}
diff --git a/app/src/main/java/com/example/catalogapp/ui/theme/Color.kt b/app/src/main/java/com/example/catalogapp/ui/theme/Color.kt
index f371e00..7e27feb 100644
--- a/app/src/main/java/com/example/catalogapp/ui/theme/Color.kt
+++ b/app/src/main/java/com/example/catalogapp/ui/theme/Color.kt
@@ -8,4 +8,4 @@ val Pink80 = Color(0xFFEFB8C8)
 
 val Purple40 = Color(0xFF6650a4)
 val PurpleGrey40 = Color(0xFF625b71)
-val Pink40 = Color(0xFF7D5260)
\ No newline at end of file
+val Pink40 = Color(0xFF7D5260)
diff --git a/app/src/main/java/com/example/catalogapp/ui/theme/Theme.kt b/app/src/main/java/com/example/catalogapp/ui/theme/Theme.kt
index 26382d8..201b822 100644
--- a/app/src/main/java/com/example/catalogapp/ui/theme/Theme.kt
+++ b/app/src/main/java/com/example/catalogapp/ui/theme/Theme.kt
@@ -1,6 +1,5 @@
 package com.example.catalogapp.ui.theme
 
-import android.app.Activity
 import android.os.Build
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.material3.MaterialTheme
diff --git a/app/src/main/java/com/example/catalogapp/ui/theme/Type.kt b/app/src/main/java/com/example/catalogapp/ui/theme/Type.kt
index 464645f..c28624b 100644
--- a/app/src/main/java/com/example/catalogapp/ui/theme/Type.kt
+++ b/app/src/main/java/com/example/catalogapp/ui/theme/Type.kt
@@ -31,4 +31,4 @@ val Typography = Typography(
         letterSpacing = 0.5.sp
     )
     */
-)
\ No newline at end of file
+)
diff --git a/app/src/main/res/color/catalog_background.xml b/app/src/main/res/color/catalog_background.xml
new file mode 100644
index 0000000..a8b409b
--- /dev/null
+++ b/app/src/main/res/color/catalog_background.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+
+</selector>
\ No newline at end of file
diff --git a/build.gradle.kts b/build.gradle.kts
index 63730c1..ee19ddb 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -7,4 +7,6 @@ plugins {
     alias(libs.plugins.kotlin.compose) apply false
     alias(libs.plugins.hilt) apply false
     alias(libs.plugins.ksp) apply false
+    alias(libs.plugins.detekt) apply false
+    alias(libs.plugins.kotlin.serialization) apply false
 }
diff --git a/catalogapp-release b/catalogapp-release
new file mode 100644
index 0000000..c0e5c52
Binary files /dev/null and b/catalogapp-release differ
diff --git a/config/detekt/detekt.yml b/config/detekt/detekt.yml
new file mode 100644
index 0000000..9346b9b
--- /dev/null
+++ b/config/detekt/detekt.yml
@@ -0,0 +1,82 @@
+build:
+  maxIssues: 0
+  excludeCorrectable: false
+
+complexity:
+  active: true
+  LongMethod:
+    active: true
+    threshold: 60
+  LongParameterList:
+    active: true
+    functionThreshold: 6
+    constructorThreshold: 7
+  CyclomaticComplexMethod:
+    active: true
+    threshold: 15
+  TooManyFunctions:
+    active: true
+    thresholdInClasses: 20
+  LargeClass:
+    active: true
+    threshold: 600
+
+naming:
+  active: true
+  FunctionNaming:
+    active: true
+    # Allow PascalCase for Composable functions - this is the correct Compose convention
+    excludes: [ '**/ui/theme/**' ]
+    functionPattern: '([a-z][a-zA-Z0-9]*)|(^[A-Z][a-zA-Z0-9]*$)'
+  ClassNaming:
+    active: true
+  VariableNaming:
+    active: true
+
+style:
+  active: true
+  MagicNumber:
+    active: true
+    excludes:
+      - '**/test/**'
+      - '**/androidTest/**'
+      - '**/ui/theme/**'
+      - '**/designsystem/theme/**'
+      - '**/designsystem/components/**'
+    ignoreNumbers: [ '-1', '0', '1', '2' ]
+    ignorePropertyDeclaration: true
+    ignoreConstantDeclaration: true
+    ignoreCompanionObjectPropertyDeclaration: true
+    ignoreNamedArgument: true
+    ignoreEnums: true
+    ignoreHashCodeFunction: true
+  MaxLineLength:
+    active: true
+    maxLineLength: 120
+  WildcardImport:
+    active: true
+  UnusedImports:
+    active: true
+  ReturnCount:
+    active: true
+    max: 3
+  NewLineAtEndOfFile:
+    active: true
+
+exceptions:
+  active: true
+  TooGenericExceptionCaught:
+    active: true
+    exceptionNames:
+      - 'Exception'
+      - 'Throwable'
+      - 'RuntimeException'
+  SwallowedException:
+    active: true
+
+potential-bugs:
+  active: true
+  UnreachableCode:
+    active: true
+  UnsafeCallOnNullableType:
+    active: true
diff --git a/core/common/build.gradle.kts b/core/common/build.gradle.kts
index 0de80e5..c27d84e 100644
--- a/core/common/build.gradle.kts
+++ b/core/common/build.gradle.kts
@@ -1,5 +1,17 @@
 plugins {
     alias(libs.plugins.kotlin.jvm)
+    jacoco
+    alias(libs.plugins.detekt)
+}
+
+jacoco {
+    toolVersion = "0.8.12"
+}
+
+detekt {
+    config.setFrom(files("$rootDir/config/detekt/detekt.yml"))
+    buildUponDefaultConfig = true
+    source.setFrom("src/main/java")
 }
 
 dependencies {
diff --git a/core/designsystem/.gitignore b/core/designsystem/.gitignore
new file mode 100644
index 0000000..42afabf
--- /dev/null
+++ b/core/designsystem/.gitignore
@@ -0,0 +1 @@
+/build
\ No newline at end of file
diff --git a/core/designsystem/build.gradle.kts b/core/designsystem/build.gradle.kts
new file mode 100644
index 0000000..ffc190a
--- /dev/null
+++ b/core/designsystem/build.gradle.kts
@@ -0,0 +1,40 @@
+plugins {
+    alias(libs.plugins.android.library)
+    alias(libs.plugins.kotlin.compose)
+    alias(libs.plugins.detekt)
+}
+
+android {
+    namespace = "com.example.catalogapp.core.designsystem"
+    compileSdk = 36
+
+    defaultConfig {
+        minSdk = 24
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    buildFeatures {
+        compose = true
+    }
+}
+
+detekt {
+    config.setFrom(files("$rootDir/config/detekt/detekt.yml"))
+    buildUponDefaultConfig = true
+    source.setFrom("src/main/java")
+}
+
+dependencies {
+    implementation(platform(libs.androidx.compose.bom))
+    implementation(libs.androidx.compose.ui)
+    implementation(libs.androidx.compose.material3)
+    implementation(libs.androidx.compose.ui.tooling.preview)
+    implementation(libs.androidx.google.fonts)
+    debugImplementation(libs.androidx.compose.ui.tooling)
+    implementation(libs.coil.compose)
+    implementation(libs.androidx.compose.material.icons.extended)
+}
diff --git a/core/designsystem/consumer-rules.pro b/core/designsystem/consumer-rules.pro
new file mode 100644
index 0000000..e69de29
diff --git a/core/designsystem/proguard-rules.pro b/core/designsystem/proguard-rules.pro
new file mode 100644
index 0000000..481bb43
--- /dev/null
+++ b/core/designsystem/proguard-rules.pro
@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile
\ No newline at end of file
diff --git a/core/designsystem/src/androidTest/java/com/example/catalogapp/core/designsystem/ExampleInstrumentedTest.kt b/core/designsystem/src/androidTest/java/com/example/catalogapp/core/designsystem/ExampleInstrumentedTest.kt
new file mode 100644
index 0000000..0d3861e
--- /dev/null
+++ b/core/designsystem/src/androidTest/java/com/example/catalogapp/core/designsystem/ExampleInstrumentedTest.kt
@@ -0,0 +1,24 @@
+package com.example.catalogapp.core.designsystem
+
+import androidx.test.platform.app.InstrumentationRegistry
+import androidx.test.ext.junit.runners.AndroidJUnit4
+
+import org.junit.Test
+import org.junit.runner.RunWith
+
+import org.junit.Assert.*
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+@RunWith(AndroidJUnit4::class)
+class ExampleInstrumentedTest {
+    @Test
+    fun useAppContext() {
+        // Context of the app under test.
+        val appContext = InstrumentationRegistry.getInstrumentation().targetContext
+        assertEquals("com.example.catalogapp.core.designsystem.test", appContext.packageName)
+    }
+}
diff --git a/core/designsystem/src/main/AndroidManifest.xml b/core/designsystem/src/main/AndroidManifest.xml
new file mode 100644
index 0000000..8bdb7e1
--- /dev/null
+++ b/core/designsystem/src/main/AndroidManifest.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+</manifest>
diff --git a/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/components/CatalogAsyncImage.kt b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/components/CatalogAsyncImage.kt
new file mode 100644
index 0000000..f456174
--- /dev/null
+++ b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/components/CatalogAsyncImage.kt
@@ -0,0 +1,75 @@
+package com.example.catalogapp.core.designsystem.components
+
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.BrokenImage
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.painter.ColorPainter
+import androidx.compose.ui.graphics.painter.Painter
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.platform.LocalContext
+import coil.compose.AsyncImage
+import coil.request.ImageRequest
+
+private const val IMAGE_CROSSFADE_DURATION_MS = 300
+
+data class CatalogImagePlaceholders(
+    val placeholder: Painter,
+    val errorBackground: Painter
+) {
+    companion object {
+        @Composable
+        fun default(): CatalogImagePlaceholders {
+            val tonal = ColorPainter(MaterialTheme.colorScheme.surfaceContainerHigh)
+            return CatalogImagePlaceholders(placeholder = tonal, errorBackground = tonal)
+        }
+    }
+}
+
+@Composable
+fun CatalogAsyncImage(
+    imageUrl: String?,
+    contentDescription: String?,
+    modifier: Modifier = Modifier,
+    contentScale: ContentScale = ContentScale.Crop,
+    placeholders: CatalogImagePlaceholders = CatalogImagePlaceholders.default()
+) {
+    var isError by remember(imageUrl) { mutableStateOf(false) }
+
+    Box(modifier = modifier.fillMaxSize()) {
+        AsyncImage(
+            model = ImageRequest.Builder(LocalContext.current)
+                .data(imageUrl)
+                .crossfade(IMAGE_CROSSFADE_DURATION_MS)
+                .build(),
+            contentDescription = contentDescription,
+            placeholder = placeholders.placeholder,
+            error = placeholders.errorBackground,
+            onError = { isError = true },
+            onSuccess = { isError = false },
+            contentScale = contentScale,
+            modifier = Modifier.fillMaxSize(),
+        )
+
+        if (isError) {
+            Icon(
+                imageVector = Icons.Default.BrokenImage,
+                contentDescription = null,
+                modifier = Modifier
+                    .align(Alignment.Center)
+                    .then(Modifier),
+                tint = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.5f)
+            )
+        }
+    }
+}
+
diff --git a/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/components/CatalogComponents.kt b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/components/CatalogComponents.kt
new file mode 100644
index 0000000..577d580
--- /dev/null
+++ b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/components/CatalogComponents.kt
@@ -0,0 +1,122 @@
+package com.example.catalogapp.core.designsystem.components
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.material3.Button
+import androidx.compose.material3.CircularProgressIndicator
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableLongStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+
+private const val RETRY_BUTTON_WIDTH_FRACTION = 0.6f
+private const val DEBOUNCE_INTERVAL_MS = 500L
+
+@Composable
+fun CatalogLoadingState(
+    modifier: Modifier = Modifier
+) {
+    Box(
+        modifier = modifier.fillMaxSize(),
+        contentAlignment = Alignment.Center
+    ) {
+        CircularProgressIndicator(
+            modifier = Modifier.size(48.dp),
+            color = MaterialTheme.colorScheme.primary,
+            strokeWidth = 3.dp
+        )
+    }
+}
+
+@Composable
+fun CatalogErrorState(
+    message: String,
+    onRetry: () -> Unit,
+    modifier: Modifier = Modifier
+) {
+    val spacing = CatalogTheme.spacing
+
+    Column(
+        modifier = modifier
+            .fillMaxSize()
+            .padding(spacing.xl),
+        horizontalAlignment = Alignment.CenterHorizontally,
+        verticalArrangement = Arrangement.Center
+    ) {
+        Text(
+            text = "Something went wrong",
+            style = MaterialTheme.typography.titleLarge,
+            color = MaterialTheme.colorScheme.onSurface
+        )
+        Spacer(modifier = Modifier.height(spacing.sm))
+        Text(
+            text = message,
+            style = MaterialTheme.typography.bodyMedium,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            textAlign = TextAlign.Center
+        )
+        Spacer(modifier = Modifier.height(spacing.lg))
+        Button(
+            onClick = onRetry,
+            modifier = Modifier.fillMaxWidth(RETRY_BUTTON_WIDTH_FRACTION)
+        ) {
+            Text(text = "Retry")
+        }
+    }
+}
+
+@Composable
+fun CatalogEmptyState(
+    message: String,
+    modifier: Modifier = Modifier
+) {
+    val spacing = CatalogTheme.spacing
+
+    Column(
+        modifier = modifier
+            .fillMaxSize()
+            .padding(spacing.xl),
+        horizontalAlignment = Alignment.CenterHorizontally,
+        verticalArrangement = Arrangement.Center
+    ) {
+        Text(
+            text = "Nothing here yet",
+            style = MaterialTheme.typography.titleLarge,
+            color = MaterialTheme.colorScheme.onSurface
+        )
+        Spacer(modifier = Modifier.height(spacing.sm))
+        Text(
+            text = message,
+            style = MaterialTheme.typography.bodyMedium,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            textAlign = TextAlign.Center
+        )
+    }
+}
+
+@Composable
+fun rememberDebouncedOnClick(onClick: () -> Unit): () -> Unit {
+    var lastClickTimeMs by remember { mutableLongStateOf(0L) }
+    return {
+        val now = System.currentTimeMillis()
+        if (now - lastClickTimeMs >= DEBOUNCE_INTERVAL_MS) {
+            lastClickTimeMs = now
+            onClick()
+        }
+    }
+}
diff --git a/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/components/DetailHeroImageDefaults.kt b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/components/DetailHeroImageDefaults.kt
new file mode 100644
index 0000000..ea35bde
--- /dev/null
+++ b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/components/DetailHeroImageDefaults.kt
@@ -0,0 +1,7 @@
+package com.example.catalogapp.core.designsystem.components
+
+object DetailHeroImageDefaults {
+    const val HERO_ASPECT_WIDTH = 4f
+    const val HERO_ASPECT_HEIGHT = 5f
+    const val GRADIENT_START_FRACTION = 0.5f
+}
diff --git a/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/components/ProductCardDefaults.kt b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/components/ProductCardDefaults.kt
new file mode 100644
index 0000000..c68d1ee
--- /dev/null
+++ b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/components/ProductCardDefaults.kt
@@ -0,0 +1,12 @@
+package com.example.catalogapp.core.designsystem.components
+
+import androidx.compose.ui.unit.dp
+
+// Promoted from feature:catalog into core:designsystem so BOTH
+// ProductCard (real) and ProductCardSkeleton (loading) reference the same constants.
+// This is the single source of truth for product card dimensions.
+object ProductCardDefaults {
+    const val IMAGE_ASPECT_WIDTH = 4f
+    const val IMAGE_ASPECT_HEIGHT = 5f
+    val CORNER_RADIUS = 12.dp
+}
diff --git a/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/components/SkeletonComponents.kt b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/components/SkeletonComponents.kt
new file mode 100644
index 0000000..f3d4ee7
--- /dev/null
+++ b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/components/SkeletonComponents.kt
@@ -0,0 +1,281 @@
+package com.example.catalogapp.core.designsystem.components
+
+import androidx.compose.animation.core.LinearEasing
+import androidx.compose.animation.core.RepeatMode
+import androidx.compose.animation.core.animateFloat
+import androidx.compose.animation.core.infiniteRepeatable
+import androidx.compose.animation.core.rememberInfiniteTransition
+import androidx.compose.animation.core.tween
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.aspectRatio
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.offset
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.Card
+import androidx.compose.material3.CardDefaults
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.graphics.Brush
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.components.DetailHeroImageDefaults.HERO_ASPECT_HEIGHT
+import com.example.catalogapp.core.designsystem.components.DetailHeroImageDefaults.HERO_ASPECT_WIDTH
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+
+private const val SHIMMER_ANIMATION_DURATION_MS = 1200
+private const val SHIMMER_TRANSLATE_TARGET = 1000f
+private val ChipCornerRadius = 12.dp
+private val ChipSkeletonWidthDp = 72.dp
+private val ChipSkeletonHeightDp = 32.dp
+private val ChipSkeletonWidths = listOf(56.dp, 88.dp, 72.dp, 64.dp)
+private val DetailSkeletonCardCorner = 24.dp
+private val DetailSkeletonFeatureGridHeight = 96.dp
+private const val CARD_OVERLAP_DP = 48
+
+/**
+ * Shared shimmer brush used by every skeleton in the design system.
+ * Colors intentionally come from MaterialTheme so light/dark mode both work correctly.
+ */
+@Composable
+internal fun rememberShimmerBrush(): Brush {
+    val shimmerColors = listOf(
+        MaterialTheme.colorScheme.surfaceContainerHigh,
+        MaterialTheme.colorScheme.surfaceContainerHighest,
+        MaterialTheme.colorScheme.surfaceContainerHigh
+    )
+    val transition = rememberInfiniteTransition(label = "shimmer")
+    val translateAnimation by transition.animateFloat(
+        initialValue = 0f,
+        targetValue = SHIMMER_TRANSLATE_TARGET,
+        animationSpec = infiniteRepeatable(
+            animation = tween(
+                durationMillis = SHIMMER_ANIMATION_DURATION_MS,
+                easing = LinearEasing
+            ),
+            repeatMode = RepeatMode.Restart
+        ),
+        label = "shimmer_translate"
+    )
+    return Brush.linearGradient(
+        colors = shimmerColors,
+        start = Offset(translateAnimation - SHIMMER_TRANSLATE_TARGET, 0f),
+        end = Offset(translateAnimation, SHIMMER_TRANSLATE_TARGET)
+    )
+}
+
+@Composable
+private fun ShimmerBox(modifier: Modifier = Modifier) {
+    Column(modifier = modifier.background(rememberShimmerBrush())) {}
+}
+
+@Composable
+fun CategoryChipSkeleton(modifier: Modifier = Modifier) {
+    Surface(
+        modifier = modifier,
+        shape = RoundedCornerShape(ChipCornerRadius),
+        color = MaterialTheme.colorScheme.surfaceContainerHigh
+    ) {
+        Column(
+            modifier = Modifier
+                .width(ChipSkeletonWidthDp)
+                .height(ChipSkeletonHeightDp)
+                .background(rememberShimmerBrush())
+        ) {}
+    }
+}
+
+@Composable
+fun CategoryChipRowSkeleton(modifier: Modifier = Modifier) {
+    Row(
+        modifier = modifier,
+        horizontalArrangement = Arrangement.spacedBy(CatalogTheme.spacing.sm)
+    ) {
+        ChipSkeletonWidths.forEach { width ->
+            Surface(
+                shape = RoundedCornerShape(ChipCornerRadius),
+                color = MaterialTheme.colorScheme.surfaceContainerHigh
+            ) {
+                Column(
+                    modifier = Modifier
+                        .width(width)
+                        .height(ChipSkeletonHeightDp)
+                        .background(rememberShimmerBrush())
+                ) {
+                    CategoryChipSkeleton()
+                }
+            }
+        }
+    }
+}
+
+/**
+ * Mirrors ProductCard's exact dimensions: square image area, two-line title,
+ * price bar. Used in ProductGridSkeleton while catalog data loads.
+ */
+@Composable
+fun ProductCardSkeleton(modifier: Modifier = Modifier) {
+    val spacing = CatalogTheme.spacing
+    Card(
+        modifier = modifier.fillMaxWidth(),
+        shape = RoundedCornerShape(ProductCardDefaults.CORNER_RADIUS),
+        colors = CardDefaults.cardColors(
+            containerColor = MaterialTheme.colorScheme.surfaceContainerLowest
+        ),
+        elevation = CardDefaults.cardElevation(defaultElevation = 0.dp)
+    ) {
+        Column {
+            // Image area — SAME aspect ratio constants as ProductImageSection
+            ShimmerBox(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .aspectRatio(
+                        ProductCardDefaults.IMAGE_ASPECT_WIDTH /
+                                ProductCardDefaults.IMAGE_ASPECT_HEIGHT
+                    )
+            )
+            // Info area — SAME padding/spacing tokens as ProductInfoSection
+            Column(
+                modifier = Modifier.padding(spacing.md),
+                verticalArrangement = Arrangement.spacedBy(spacing.xs)
+            ) {
+                // Title — 2 lines, matches maxLines = 2 on the real title
+                ShimmerBox(
+                    modifier = Modifier
+                        .fillMaxWidth(0.9f)
+                        .height(spacing.md)
+                )
+                ShimmerBox(
+                    modifier = Modifier
+                        .fillMaxWidth(0.6f)
+                        .height(spacing.md)
+                )
+                // Rating row placeholder — matches RatingRow's height
+                ShimmerBox(
+                    modifier = Modifier
+                        .width(60.dp)
+                        .height(spacing.sm)
+                )
+                // Price — matches titleMedium text block
+                ShimmerBox(
+                    modifier = Modifier
+                        .width(70.dp)
+                        .height(spacing.md)
+                )
+            }
+        }
+    }
+}
+
+/**
+ * Mirrors the detail screen's content card sections below the hero image:
+ * title, price, and a features-grid placeholder. The hero image itself
+ * is NOT shimmered here — Coil's placeholder() handles that separately.
+ */
+@Composable
+fun DetailSkeleton(modifier: Modifier = Modifier) {
+    val spacing = CatalogTheme.spacing
+    Column(modifier = modifier.fillMaxWidth()) {
+        Column(
+            modifier = Modifier
+                .fillMaxWidth()
+                .aspectRatio(HERO_ASPECT_WIDTH / HERO_ASPECT_HEIGHT)
+                .background(rememberShimmerBrush())
+        ) {}
+
+        Box(modifier = Modifier.padding(horizontal = spacing.md)) {
+            DetailSkeletonContentCard()
+        }
+    }
+}
+
+@Composable
+private fun DetailSkeletonContentCard() {
+    val spacing = CatalogTheme.spacing
+    Card(
+        modifier = Modifier
+            .fillMaxWidth()
+            .offset(y = -CARD_OVERLAP_DP.dp),
+        shape = RoundedCornerShape(DetailSkeletonCardCorner),
+        colors = CardDefaults.cardColors(
+            containerColor = MaterialTheme.colorScheme.surfaceContainerLowest
+        ),
+        elevation = CardDefaults.cardElevation(defaultElevation = 2.dp)
+    ) {
+        Column(modifier = Modifier
+            .fillMaxWidth()
+            .padding(spacing.md)) {
+            DetailSkeletonHeader()
+            Spacer(modifier = Modifier.height(spacing.lg))
+            DetailSkeletonPriceAndFeatures()
+            Spacer(modifier = Modifier.height(spacing.xl))
+            DetailSkeletonDescriptionLines()
+        }
+    }
+}
+
+@Composable
+private fun DetailSkeletonHeader() {
+    val spacing = CatalogTheme.spacing
+    Column(
+        modifier = Modifier
+            .fillMaxWidth(0.7f)
+            .height(spacing.lg)
+            .background(rememberShimmerBrush())
+    ) {}
+    Spacer(modifier = Modifier.height(spacing.sm))
+    Column(
+        modifier = Modifier
+            .width(100.dp)
+            .height(spacing.md)
+            .background(rememberShimmerBrush())
+    ) {}
+}
+
+@Composable
+private fun DetailSkeletonPriceAndFeatures() {
+    val spacing = CatalogTheme.spacing
+    Column(
+        modifier = Modifier
+            .width(80.dp)
+            .height(spacing.lg)
+            .background(rememberShimmerBrush())
+    ) {}
+    Spacer(modifier = Modifier.height(spacing.lg))
+    Row(horizontalArrangement = Arrangement.spacedBy(spacing.sm)) {
+        repeat(2) {
+            Column(
+                modifier = Modifier
+                    .weight(1f)
+                    .height(DetailSkeletonFeatureGridHeight)
+                    .background(rememberShimmerBrush())
+            ) {}
+        }
+    }
+}
+
+@Composable
+private fun DetailSkeletonDescriptionLines() {
+    val spacing = CatalogTheme.spacing
+    Column(verticalArrangement = Arrangement.spacedBy(spacing.xs)) {
+        repeat(3) { index ->
+            val widthFraction = if (index == 2) 0.5f else 1f
+            Column(
+                modifier = Modifier
+                    .fillMaxWidth(widthFraction)
+                    .height(spacing.sm)
+                    .background(rememberShimmerBrush())
+            ) {}
+        }
+    }
+}
diff --git a/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/preview/CatalogAsyncImagePreview.kt b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/preview/CatalogAsyncImagePreview.kt
new file mode 100644
index 0000000..868e702
--- /dev/null
+++ b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/preview/CatalogAsyncImagePreview.kt
@@ -0,0 +1,69 @@
+package com.example.catalogapp.core.designsystem.preview
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.BrokenImage
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+
+// This mirrors CatalogAsyncImage's PLACEHOLDER state visually —
+// can't preview the real Coil pipeline since no network call runs in @Preview.
+@Composable
+private fun PlaceholderStatePreview() {
+    Box(
+        modifier = Modifier
+            .size(100.dp)
+            .background(MaterialTheme.colorScheme.surfaceContainerHigh)
+    )
+}
+
+// Mirrors CatalogAsyncImage's ERROR state visually — tonal box + muted icon overlay
+@Composable
+private fun ErrorStatePreview() {
+    Box(
+        modifier = Modifier.size(100.dp),
+        contentAlignment = Alignment.Center
+    ) {
+        Box(
+            modifier = Modifier
+                .size(100.dp)
+                .background(MaterialTheme.colorScheme.surfaceContainerHigh)
+        )
+        Icon(
+            imageVector = Icons.Default.BrokenImage,
+            contentDescription = null,
+            tint = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = 0.5f)
+        )
+    }
+}
+
+@Preview(name = "Light", showBackground = true)
+@Preview(name = "Dark", showBackground = true, uiMode = 0x20)
+@Composable
+internal fun CatalogAsyncImageStatesPreview() {
+    CatalogTheme {
+        Row(
+            modifier = Modifier.padding(16.dp),
+            horizontalArrangement = androidx.compose.foundation.layout.Arrangement.spacedBy(16.dp)
+        ) {
+            Column {
+                PlaceholderStatePreview()
+            }
+            Column {
+                ErrorStatePreview()
+            }
+        }
+    }
+}
+
diff --git a/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/preview/ThemePreview.kt b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/preview/ThemePreview.kt
new file mode 100644
index 0000000..ee54808
--- /dev/null
+++ b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/preview/ThemePreview.kt
@@ -0,0 +1,307 @@
+package com.example.catalogapp.core.designsystem.preview
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.Button
+import androidx.compose.material3.Card
+import androidx.compose.material3.CardDefaults
+import androidx.compose.material3.FilterChip
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedButton
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.components.CatalogEmptyState
+import com.example.catalogapp.core.designsystem.components.CatalogErrorState
+import com.example.catalogapp.core.designsystem.components.CatalogLoadingState
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+
+// ─── Color palette preview ────────────────────────────────────────────────────
+@Preview(showBackground = true, name = "Color Palette - Light")
+@Preview(
+    showBackground = true,
+    name = "Color Palette - Dark",
+    uiMode = android.content.res.Configuration.UI_MODE_NIGHT_YES
+)
+@Composable
+internal fun ColorPalettePreview() {
+    CatalogTheme {
+        Surface {
+            Column(
+                modifier = Modifier.padding(16.dp),
+                verticalArrangement = Arrangement.spacedBy(8.dp)
+            ) {
+                Text(
+                    text = "Color Palette",
+                    style = MaterialTheme.typography.titleLarge
+                )
+                Spacer(modifier = Modifier.height(8.dp))
+                ColorRow(
+                    "Primary",
+                    MaterialTheme.colorScheme.primary,
+                    MaterialTheme.colorScheme.onPrimary
+                )
+                ColorRow(
+                    "Primary Container",
+                    MaterialTheme.colorScheme.primaryContainer,
+                    MaterialTheme.colorScheme.onPrimaryContainer
+                )
+                ColorRow(
+                    "Secondary",
+                    MaterialTheme.colorScheme.secondary,
+                    MaterialTheme.colorScheme.onSecondary
+                )
+                ColorRow(
+                    "Secondary Container",
+                    MaterialTheme.colorScheme.secondaryContainer,
+                    MaterialTheme.colorScheme.onSecondaryContainer
+                )
+                ColorRow(
+                    "Surface",
+                    MaterialTheme.colorScheme.surface,
+                    MaterialTheme.colorScheme.onSurface
+                )
+                ColorRow(
+                    "Background",
+                    MaterialTheme.colorScheme.background,
+                    MaterialTheme.colorScheme.onBackground
+                )
+                ColorRow(
+                    "Error",
+                    MaterialTheme.colorScheme.error,
+                    MaterialTheme.colorScheme.onError
+                )
+            }
+        }
+    }
+}
+
+@Composable
+internal fun ColorRow(name: String, color: Color, onColor: Color) {
+    Row(verticalAlignment = Alignment.CenterVertically, modifier = Modifier.fillMaxWidth()) {
+        Box(
+            modifier = Modifier
+                .size(width = 120.dp, height = 48.dp)
+                .background(color, RoundedCornerShape(8.dp)),
+            contentAlignment = Alignment.Center
+        ) {
+            Text(text = name, color = onColor, style = MaterialTheme.typography.labelSmall)
+        }
+        Spacer(modifier = Modifier.width(12.dp))
+        Text(
+            text = name,
+            style = MaterialTheme.typography.bodySmall,
+            color = MaterialTheme.colorScheme.onSurface
+        )
+    }
+}
+
+// ─── Typography preview ───────────────────────────────────────────────────────
+@Preview(showBackground = true, name = "Typography - Light")
+@Preview(
+    showBackground = true,
+    name = "Typography - Dark",
+    uiMode = android.content.res.Configuration.UI_MODE_NIGHT_YES
+)
+@Composable
+internal fun TypographyPreview() {
+    CatalogTheme {
+        Surface {
+            Column(
+                modifier = Modifier.padding(16.dp),
+                verticalArrangement = Arrangement.spacedBy(8.dp)
+            ) {
+                Text("Headline Large", style = MaterialTheme.typography.headlineLarge)
+                Text("Headline Medium", style = MaterialTheme.typography.headlineMedium)
+                Text("Title Large", style = MaterialTheme.typography.titleLarge)
+                Text("Title Medium", style = MaterialTheme.typography.titleMedium)
+                Text("Title Small", style = MaterialTheme.typography.titleSmall)
+                Text("Body Large", style = MaterialTheme.typography.bodyLarge)
+                Text("Body Medium", style = MaterialTheme.typography.bodyMedium)
+                Text("Body Small", style = MaterialTheme.typography.bodySmall)
+                Text("Label Large", style = MaterialTheme.typography.labelLarge)
+                Text("Label Medium", style = MaterialTheme.typography.labelMedium)
+                Text("Label Small", style = MaterialTheme.typography.labelSmall)
+            }
+        }
+    }
+}
+
+// ─── Buttons and chips preview ────────────────────────────────────────────────
+@Preview(showBackground = true, name = "Buttons - Light")
+@Preview(
+    showBackground = true,
+    name = "Buttons - Dark",
+    uiMode = android.content.res.Configuration.UI_MODE_NIGHT_YES
+)
+@Composable
+internal fun ButtonPreview() {
+    CatalogTheme {
+        Surface {
+            Column(
+                modifier = Modifier.padding(16.dp),
+                verticalArrangement = Arrangement.spacedBy(12.dp)
+            ) {
+                Text("Buttons", style = MaterialTheme.typography.titleLarge)
+                Button(onClick = {}, modifier = Modifier.fillMaxWidth()) {
+                    Text("Primary Button")
+                }
+                OutlinedButton(onClick = {}, modifier = Modifier.fillMaxWidth()) {
+                    Text("Outlined Button")
+                }
+                Row(horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+                    FilterChip(selected = true, onClick = {}, label = { Text("Active") })
+                    FilterChip(selected = false, onClick = {}, label = { Text("Inactive") })
+                }
+            }
+        }
+    }
+}
+
+// ─── Product card preview ─────────────────────────────────────────────────────
+@Preview(showBackground = true, name = "Product Card - Light")
+@Preview(
+    showBackground = true,
+    name = "Product Card - Dark",
+    uiMode = android.content.res.Configuration.UI_MODE_NIGHT_YES
+)
+@Composable
+internal fun ProductCardPreview() {
+    CatalogTheme {
+        val spacing = CatalogTheme.spacing
+        Surface {
+            Column(modifier = Modifier.padding(spacing.md)) {
+                Text(
+                    text = "Product Card",
+                    style = MaterialTheme.typography.titleLarge,
+                    modifier = Modifier.padding(bottom = spacing.sm)
+                )
+                Card(
+                    modifier = Modifier.width(180.dp),
+                    shape = MaterialTheme.shapes.large,
+                    elevation = CardDefaults.cardElevation(defaultElevation = 2.dp)
+                ) {
+                    Column {
+                        Box(
+                            modifier = Modifier
+                                .fillMaxWidth()
+                                .height(160.dp)
+                                .background(MaterialTheme.colorScheme.surfaceVariant),
+                            contentAlignment = Alignment.Center
+                        ) {
+                            Text(
+                                text = "Product Image",
+                                style = MaterialTheme.typography.labelMedium,
+                                color = MaterialTheme.colorScheme.onSurfaceVariant
+                            )
+                        }
+                        Column(modifier = Modifier.padding(spacing.sm)) {
+                            Text(
+                                text = "Fjallraven Backpack",
+                                style = MaterialTheme.typography.titleSmall,
+                                maxLines = 2
+                            )
+                            Text(
+                                text = "₹8,999",
+                                style = MaterialTheme.typography.titleMedium,
+                                color = MaterialTheme.colorScheme.primary
+                            )
+                            Text(
+                                text = "⭐ 3.9 (120)",
+                                style = MaterialTheme.typography.labelMedium,
+                                color = MaterialTheme.colorScheme.onSurfaceVariant
+                            )
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+// ─── Spacing preview ──────────────────────────────────────────────────────────
+@Preview(showBackground = true, name = "Spacing Scale")
+@Composable
+internal fun SpacingPreview() {
+    CatalogTheme {
+        val spacing = CatalogTheme.spacing
+        Surface {
+            Column(
+                modifier = Modifier.padding(spacing.md),
+                verticalArrangement = Arrangement.spacedBy(spacing.sm)
+            ) {
+                Text("Spacing Scale", style = MaterialTheme.typography.titleLarge)
+                SpacingRow("xs = 4dp", spacing.xs)
+                SpacingRow("sm = 8dp", spacing.sm)
+                SpacingRow("md = 16dp", spacing.md)
+                SpacingRow("lg = 24dp", spacing.lg)
+                SpacingRow("xl = 32dp", spacing.xl)
+            }
+        }
+    }
+}
+
+@Composable
+internal fun SpacingRow(label: String, size: Dp) {
+    Row(verticalAlignment = Alignment.CenterVertically, modifier = Modifier.fillMaxWidth()) {
+        Text(
+            text = label,
+            style = MaterialTheme.typography.bodyMedium,
+            modifier = Modifier.width(100.dp)
+        )
+        Box(
+            modifier = Modifier
+                .width(size * 2)
+                .height(24.dp)
+                .background(MaterialTheme.colorScheme.primary, RoundedCornerShape(4.dp))
+        )
+    }
+}
+
+// ─── State components preview ─────────────────────────────────────────────────
+@Preview(showBackground = true, name = "Loading State", heightDp = 300)
+@Composable
+internal fun LoadingPreview() {
+    CatalogTheme {
+        Surface { CatalogLoadingState() }
+    }
+}
+
+@Preview(showBackground = true, name = "Error State", heightDp = 400)
+@Composable
+internal fun ErrorPreview() {
+    CatalogTheme {
+        Surface {
+            CatalogErrorState(
+                message = "Unable to load products. Please check your connection.",
+                onRetry = {}
+            )
+        }
+    }
+}
+
+@Preview(showBackground = true, name = "Empty State", heightDp = 400)
+@Composable
+internal fun EmptyPreview() {
+    CatalogTheme {
+        Surface {
+            CatalogEmptyState(message = "No products found in this category.")
+        }
+    }
+}
diff --git a/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/theme/Color.kt b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/theme/Color.kt
new file mode 100644
index 0000000..c368260
--- /dev/null
+++ b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/theme/Color.kt
@@ -0,0 +1,89 @@
+package com.example.catalogapp.core.designsystem.theme
+
+import androidx.compose.ui.graphics.Color
+
+// ─── Primary — Indigo/Violet ──────────────────────────────────────────────────
+val Primary = Color(0xFF3525CD)
+val OnPrimary = Color(0xFFFFFFFF)
+val PrimaryContainer = Color(0xFF4F46E5)
+val OnPrimaryContainer = Color(0xFFDAD7FF)
+val InversePrimary = Color(0xFFC3C0FF)
+
+// ─── Secondary — Amber/Gold ───────────────────────────────────────────────────
+val Secondary = Color(0xFF855300)
+val OnSecondary = Color(0xFFFFFFFF)
+val SecondaryContainer = Color(0xFFFEA619)
+val OnSecondaryContainer = Color(0xFF684000)
+
+// ─── Tertiary — Violet ────────────────────────────────────────────────────────
+val Tertiary = Color(0xFF5C01C9)
+val OnTertiary = Color(0xFFFFFFFF)
+val TertiaryContainer = Color(0xFF7534E1)
+val OnTertiaryContainer = Color(0xFFE4D4FF)
+
+// ─── Error ────────────────────────────────────────────────────────────────────
+val Error = Color(0xFFBA1A1A)
+val OnError = Color(0xFFFFFFFF)
+val ErrorContainer = Color(0xFFFFDAD6)
+val OnErrorContainer = Color(0xFF93000A)
+
+// ─── Surface & Background ─────────────────────────────────────────────────────
+val Background = Color(0xFFF8F9FA)
+val OnBackground = Color(0xFF191C1D)
+val Surface = Color(0xFFF8F9FA)
+val OnSurface = Color(0xFF191C1D)
+val SurfaceVariant = Color(0xFFE1E3E4)
+val OnSurfaceVariant = Color(0xFF464555)
+val SurfaceTint = Color(
+    0xFF4D44E3)
+val InverseSurface = Color(0xFF2E3132)
+val InverseOnSurface = Color(0xFFF0F1F2)
+
+// ─── Surface containers ───────────────────────────────────────────────────────
+val SurfaceContainerLowest = Color(0xFFFFFFFF)
+val SurfaceContainerLow = Color(0xFFF3F4F5)
+val SurfaceContainer = Color(0xFFEDEEEF)
+val SurfaceContainerHigh = Color(0xFFE7E8E9)
+val SurfaceContainerHighest = Color(0xFFE1E3E4)
+
+// ─── Outline ──────────────────────────────────────────────────────────────────
+val Outline = Color(0xFF777587)
+val OutlineVariant = Color(0xFFC7C4D8)
+
+// ─── Dark mode colors ─────────────────────────────────────────────────────────
+val PrimaryDark = Color(0xFFC3C0FF)
+val OnPrimaryDark = Color(0xFF1A0E8F)
+val PrimaryContainerDark = Color(0xFF2B1DB5)
+val OnPrimaryContainerDark = Color(0xFFDAD7FF)
+
+val SecondaryDark = Color(0xFFFFB95F)
+val OnSecondaryDark = Color(0xFF462A00)
+val SecondaryContainerDark = Color(0xFF643D00)
+val OnSecondaryContainerDark = Color(0xFFFFDDB8)
+
+val TertiaryDark = Color(0xFFD3BBFF)
+val OnTertiaryDark = Color(0xFF3F0090)
+val TertiaryContainerDark = Color(0xFF5800AC)
+val OnTertiaryContainerDark = Color(0xFFEBDDFF)
+
+val BackgroundDark = Color(0xFF111315)
+val OnBackgroundDark = Color(0xFFE1E3E4)
+val SurfaceDark = Color(0xFF111315)
+val OnSurfaceDark = Color(0xFFE1E3E4)
+val SurfaceVariantDark = Color(0xFF464555)
+val OnSurfaceVariantDark = Color(0xFFC7C4D8)
+val InverseSurfaceDark = Color(0xFFE1E3E4)
+val InverseOnSurfaceDark = Color(0xFF2E3132)
+
+val SurfaceContainerLowestDark = Color(0xFF0C0E0F)
+val SurfaceContainerLowDark = Color(0xFF191C1D)
+val SurfaceContainerDark = Color(0xFF1D2021)
+val SurfaceContainerHighDark = Color(0xFF272B2C)
+val SurfaceContainerHighestDark = Color(0xFF323537)
+
+val OutlineDark = Color(0xFF918FA2)
+val OutlineVariantDark = Color(0xFF464555)
+val ErrorDark = Color(0xFFFFB4AB)
+val OnErrorDark = Color(0xFF690005)
+val ErrorContainerDark = Color(0xFF93000A)
+val OnErrorContainerDark = Color(0xFFFFDAD6)
diff --git a/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/theme/Shape.kt b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/theme/Shape.kt
new file mode 100644
index 0000000..028bbdc
--- /dev/null
+++ b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/theme/Shape.kt
@@ -0,0 +1,18 @@
+package com.example.catalogapp.core.designsystem.theme
+
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.Shapes
+import androidx.compose.ui.unit.dp
+
+val CatalogShapes = Shapes(
+    // extraSmall — 4dp (Stitch sm)
+    extraSmall = RoundedCornerShape(4.dp),
+    // small — 8dp (Stitch DEFAULT)
+    small = RoundedCornerShape(8.dp),
+    // medium — 12dp (Stitch md) — chips
+    medium = RoundedCornerShape(12.dp),
+    // large — 16dp (Stitch lg) — cards
+    large = RoundedCornerShape(16.dp),
+    // extraLarge — 24dp (Stitch xl) — buttons, search bars
+    extraLarge = RoundedCornerShape(24.dp)
+)
diff --git a/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/theme/Spacing.kt b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/theme/Spacing.kt
new file mode 100644
index 0000000..7e4aa2e
--- /dev/null
+++ b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/theme/Spacing.kt
@@ -0,0 +1,19 @@
+package com.example.catalogapp.core.designsystem.theme
+
+import androidx.compose.runtime.compositionLocalOf
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+
+data class Spacing(
+    val xs: Dp = 4.dp,       // Stitch xs
+    val sm: Dp = 8.dp,       // Stitch sm / base
+    val md: Dp = 16.dp,      // Stitch md / mobile margin
+    val lg: Dp = 24.dp,      // Stitch lg / tablet margin
+    val xl: Dp = 32.dp,      // Stitch xl — section separation
+    val xxl: Dp = 48.dp,     // extra large gaps
+    val cardPadding: Dp = 12.dp,
+    val screenPadding: Dp = 16.dp,
+    val gutter: Dp = 16.dp
+)
+
+val LocalSpacing = compositionLocalOf { Spacing() }
diff --git a/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/theme/Theme.kt b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/theme/Theme.kt
new file mode 100644
index 0000000..dfc2257
--- /dev/null
+++ b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/theme/Theme.kt
@@ -0,0 +1,122 @@
+package com.example.catalogapp.core.designsystem.theme
+
+import android.os.Build
+import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.darkColorScheme
+import androidx.compose.material3.dynamicDarkColorScheme
+import androidx.compose.material3.dynamicLightColorScheme
+import androidx.compose.material3.lightColorScheme
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.LocalContext
+
+val Scrim = Color(0xFF000000)
+
+// ─── Light color scheme — from Stitch design.md ───────────────────────────────
+private val LightColorScheme = lightColorScheme(
+    primary = Primary,
+    onPrimary = OnPrimary,
+    primaryContainer = PrimaryContainer,
+    onPrimaryContainer = OnPrimaryContainer,
+    inversePrimary = InversePrimary,
+    secondary = Secondary,
+    onSecondary = OnSecondary,
+    secondaryContainer = SecondaryContainer,
+    onSecondaryContainer = OnSecondaryContainer,
+    tertiary = Tertiary,
+    onTertiary = OnTertiary,
+    tertiaryContainer = TertiaryContainer,
+    onTertiaryContainer = OnTertiaryContainer,
+    error = Error,
+    onError = OnError,
+    errorContainer = ErrorContainer,
+    onErrorContainer = OnErrorContainer,
+    background = Background,
+    onBackground = OnBackground,
+    surface = Surface,
+    onSurface = OnSurface,
+    onSurfaceVariant = OnSurfaceVariant,
+    surfaceVariant = SurfaceVariant,
+    surfaceTint = SurfaceTint,
+    inverseSurface = InverseSurface,
+    inverseOnSurface = InverseOnSurface,
+    outline = Outline,
+    outlineVariant = OutlineVariant,
+    scrim = Scrim,
+    surfaceContainerLow = SurfaceContainerLow,
+    surfaceContainerLowest = SurfaceContainerLowest,
+    surfaceContainerHigh = SurfaceContainerHigh,
+)
+
+// ─── Dark color scheme ────────────────────────────────────────────────────────
+private val DarkColorScheme = darkColorScheme(
+    primary = PrimaryDark,
+    onPrimary = OnPrimaryDark,
+    primaryContainer = PrimaryContainerDark,
+    onPrimaryContainer = OnPrimaryContainerDark,
+    secondary = SecondaryDark,
+    onSecondary = OnSecondaryDark,
+    secondaryContainer = SecondaryContainerDark,
+    onSecondaryContainer = OnSecondaryContainerDark,
+    tertiary = TertiaryDark,
+    onTertiary = OnTertiaryDark,
+    tertiaryContainer = TertiaryContainerDark,
+    onTertiaryContainer = OnTertiaryContainerDark,
+    error = ErrorDark,
+    onError = OnErrorDark,
+    errorContainer = ErrorContainerDark,
+    onErrorContainer = OnErrorContainerDark,
+    background = BackgroundDark,
+    onBackground = OnBackgroundDark,
+    surface = SurfaceDark,
+    onSurface = OnSurfaceDark,
+    surfaceVariant = SurfaceVariantDark,
+    onSurfaceVariant = OnSurfaceVariantDark,
+    inverseSurface = InverseSurfaceDark,
+    inverseOnSurface = InverseOnSurfaceDark,
+    outline = OutlineDark,
+    outlineVariant = OutlineVariantDark,
+    surfaceContainerLow = SurfaceContainerLowDark,
+    surfaceContainerLowest = SurfaceContainerLowestDark,
+    surfaceContainerHigh = SurfaceContainerHighDark,
+)
+
+@Composable
+fun CatalogTheme(
+    darkTheme: Boolean = isSystemInDarkTheme(),
+    // Dynamic color — Android 12+ (Material You)
+    // Uses device wallpaper colors if true, falls back to our Stitch palette
+    dynamicColor: Boolean = false,
+    content: @Composable () -> Unit
+) {
+    val colorScheme = when {
+        dynamicColor && Build.VERSION.SDK_INT >= Build.VERSION_CODES.S -> {
+            val context = LocalContext.current
+            if (darkTheme) dynamicDarkColorScheme(context)
+            else dynamicLightColorScheme(context)
+        }
+
+        darkTheme -> DarkColorScheme
+        else -> LightColorScheme
+    }
+
+    CompositionLocalProvider(
+        LocalSpacing provides Spacing()
+    ) {
+        MaterialTheme(
+            colorScheme = colorScheme,
+            typography = CatalogTypography,
+            shapes = CatalogShapes,
+            content = content
+        )
+    }
+}
+
+// ─── Convenience extension — access spacing from anywhere in the theme ─────────
+object CatalogTheme {
+    val spacing: Spacing
+        @Composable
+        get() = LocalSpacing.current
+}
diff --git a/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/theme/Type.kt b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/theme/Type.kt
new file mode 100644
index 0000000..63817ce
--- /dev/null
+++ b/core/designsystem/src/main/java/com/example/catalogapp/core/designsystem/theme/Type.kt
@@ -0,0 +1,176 @@
+package com.example.catalogapp.core.designsystem.theme
+
+import androidx.compose.material3.Typography
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.googlefonts.Font
+import androidx.compose.ui.text.googlefonts.GoogleFont
+import androidx.compose.ui.unit.sp
+import com.example.catalogapp.core.designsystem.R
+
+// ─── Google Fonts provider ────────────────────────────────────────────────────
+private val provider = GoogleFont.Provider(
+    providerAuthority = "com.google.android.gms.fonts",
+    providerPackage = "com.google.android.gms",
+    certificates = R.array.com_google_android_gms_fonts_certs
+)
+
+// ─── Hanken Grotesk — headlines and titles ────────────────────────────────────
+private val HankenGroteskFont = GoogleFont("Hanken Grotesk")
+
+private val HankenGrotesk = FontFamily(
+    Font(
+        googleFont = HankenGroteskFont,
+        fontProvider = provider,
+        weight = FontWeight.Normal
+    ),
+    Font(
+        googleFont = HankenGroteskFont,
+        fontProvider = provider,
+        weight = FontWeight.Medium
+    ),
+    Font(
+        googleFont = HankenGroteskFont,
+        fontProvider = provider,
+        weight = FontWeight.SemiBold
+    ),
+    Font(
+        googleFont = HankenGroteskFont,
+        fontProvider = provider,
+        weight = FontWeight.Bold
+    )
+)
+
+// ─── Inter — body text and labels ─────────────────────────────────────────────
+private val InterFont = GoogleFont("Inter")
+
+private val Inter = FontFamily(
+    Font(
+        googleFont = InterFont,
+        fontProvider = provider,
+        weight = FontWeight.Normal
+    ),
+    Font(
+        googleFont = InterFont,
+        fontProvider = provider,
+        weight = FontWeight.Medium
+    ),
+    Font(
+        googleFont = InterFont,
+        fontProvider = provider,
+        weight = FontWeight.SemiBold
+    )
+)
+
+// ─── Typography scale — mapped from Stitch design.md ─────────────────────────
+val CatalogTypography = Typography(
+    // Display
+    displayLarge = TextStyle(
+        fontFamily = HankenGrotesk,
+        fontWeight = FontWeight.Bold,
+        fontSize = 57.sp,
+        lineHeight = 64.sp,
+        letterSpacing = (-0.25).sp
+    ),
+    displayMedium = TextStyle(
+        fontFamily = HankenGrotesk,
+        fontWeight = FontWeight.Bold,
+        fontSize = 45.sp,
+        lineHeight = 52.sp
+    ),
+    displaySmall = TextStyle(
+        fontFamily = HankenGrotesk,
+        fontWeight = FontWeight.Bold,
+        fontSize = 36.sp,
+        lineHeight = 44.sp
+    ),
+
+    // Headline — Stitch headline-lg maps here
+    headlineLarge = TextStyle(
+        fontFamily = HankenGrotesk,
+        fontWeight = FontWeight.Bold,
+        fontSize = 32.sp,
+        lineHeight = 40.sp
+    ),
+    headlineMedium = TextStyle(
+        fontFamily = HankenGrotesk,
+        fontWeight = FontWeight.Bold,
+        fontSize = 28.sp,
+        lineHeight = 36.sp
+    ),
+    headlineSmall = TextStyle(
+        fontFamily = HankenGrotesk,
+        fontWeight = FontWeight.SemiBold,
+        fontSize = 24.sp,
+        lineHeight = 32.sp
+    ),
+
+    // Title — Stitch title-lg maps here
+    titleLarge = TextStyle(
+        fontFamily = HankenGrotesk,
+        fontWeight = FontWeight.SemiBold,
+        fontSize = 22.sp,
+        lineHeight = 28.sp
+    ),
+    titleMedium = TextStyle(
+        fontFamily = HankenGrotesk,
+        fontWeight = FontWeight.SemiBold,
+        fontSize = 16.sp,
+        lineHeight = 24.sp,
+        letterSpacing = 0.15.sp
+    ),
+    titleSmall = TextStyle(
+        fontFamily = HankenGrotesk,
+        fontWeight = FontWeight.Medium,
+        fontSize = 14.sp,
+        lineHeight = 20.sp,
+        letterSpacing = 0.1.sp
+    ),
+
+    // Body — Inter for readability
+    bodyLarge = TextStyle(
+        fontFamily = Inter,
+        fontWeight = FontWeight.Normal,
+        fontSize = 16.sp,
+        lineHeight = 24.sp,
+        letterSpacing = 0.5.sp
+    ),
+    bodyMedium = TextStyle(
+        fontFamily = Inter,
+        fontWeight = FontWeight.Normal,
+        fontSize = 14.sp,
+        lineHeight = 20.sp,
+        letterSpacing = 0.25.sp
+    ),
+    bodySmall = TextStyle(
+        fontFamily = Inter,
+        fontWeight = FontWeight.Normal,
+        fontSize = 12.sp,
+        lineHeight = 16.sp,
+        letterSpacing = 0.4.sp
+    ),
+
+    // Label
+    labelLarge = TextStyle(
+        fontFamily = Inter,
+        fontWeight = FontWeight.Medium,
+        fontSize = 14.sp,
+        lineHeight = 20.sp,
+        letterSpacing = 0.1.sp
+    ),
+    labelMedium = TextStyle(
+        fontFamily = Inter,
+        fontWeight = FontWeight.Medium,
+        fontSize = 12.sp,
+        lineHeight = 16.sp,
+        letterSpacing = 0.5.sp
+    ),
+    labelSmall = TextStyle(
+        fontFamily = Inter,
+        fontWeight = FontWeight.Medium,
+        fontSize = 11.sp,
+        lineHeight = 16.sp,
+        letterSpacing = 0.5.sp
+    )
+)
diff --git a/core/designsystem/src/main/res/drawable/ic_image_error.xml b/core/designsystem/src/main/res/drawable/ic_image_error.xml
new file mode 100644
index 0000000..7608122
--- /dev/null
+++ b/core/designsystem/src/main/res/drawable/ic_image_error.xml
@@ -0,0 +1,10 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:tint="?attr/colorError"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M21,19V5a2,2 0,0 0,-2 -2H5a2,2 0,0 0,-2 2V19a2,2 0,0 0,2 2H19a2,2 0,0 0,2 -2zM8.5,13.5l2.5,3.01L14.5,12l4.5,6H5l3.5,-4.5z" />
+</vector>
\ No newline at end of file
diff --git a/core/designsystem/src/main/res/drawable/ic_product_placeholder.xml b/core/designsystem/src/main/res/drawable/ic_product_placeholder.xml
new file mode 100644
index 0000000..a9f204a
--- /dev/null
+++ b/core/designsystem/src/main/res/drawable/ic_product_placeholder.xml
@@ -0,0 +1,13 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:tint="#334F46E5"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M4,4h16v16H4z" />
+    <path
+        android:fillColor="#4F46E5"
+        android:pathData="M8,14l2.5,-3.5 2,2.5 3,-4 3.5,5H4z" />
+</vector>
\ No newline at end of file
diff --git a/core/designsystem/src/main/res/values/font_certs.xml b/core/designsystem/src/main/res/values/font_certs.xml
new file mode 100644
index 0000000..e9f0ed9
--- /dev/null
+++ b/core/designsystem/src/main/res/values/font_certs.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <array name="com_google_android_gms_fonts_certs">
+        <item>@array/com_google_android_gms_fonts_certs_dev</item>
+        <item>@array/com_google_android_gms_fonts_certs_prod</item>
+    </array>
+
+    <string-array name="com_google_android_gms_fonts_certs_dev">
+        <item>
+            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
+        </item>
+    </string-array>
+
+    <string-array name="com_google_android_gms_fonts_certs_prod">
+        <item>
+            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
+        </item>
+    </string-array>
+</resources>
diff --git a/core/designsystem/src/test/java/com/example/catalogapp/core/designsystem/ExampleUnitTest.kt b/core/designsystem/src/test/java/com/example/catalogapp/core/designsystem/ExampleUnitTest.kt
new file mode 100644
index 0000000..27138cc
--- /dev/null
+++ b/core/designsystem/src/test/java/com/example/catalogapp/core/designsystem/ExampleUnitTest.kt
@@ -0,0 +1,17 @@
+package com.example.catalogapp.core.designsystem
+
+import org.junit.Test
+
+import org.junit.Assert.*
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+class ExampleUnitTest {
+    @Test
+    fun addition_isCorrect() {
+        assertEquals(4, 2 + 2)
+    }
+}
diff --git a/core/network/build.gradle.kts b/core/network/build.gradle.kts
index f080c35..9faecb4 100644
--- a/core/network/build.gradle.kts
+++ b/core/network/build.gradle.kts
@@ -2,6 +2,7 @@ plugins {
     alias(libs.plugins.android.library)
     alias(libs.plugins.hilt)
     alias(libs.plugins.ksp)
+    alias(libs.plugins.detekt)
 }
 
 android {
@@ -22,6 +23,12 @@ android {
     }
 }
 
+detekt {
+    config.setFrom(files("$rootDir/config/detekt/detekt.yml"))
+    buildUponDefaultConfig = true
+    source.setFrom("src/main/java")
+}
+
 dependencies {
     implementation(libs.retrofit.core)
     implementation(libs.retrofit.converter.gson)
diff --git a/core/network/src/main/java/com/example/catalogapp/core/network/ConnectivityChecker.kt b/core/network/src/main/java/com/example/catalogapp/core/network/ConnectivityChecker.kt
index 0669a47..1faf275 100644
--- a/core/network/src/main/java/com/example/catalogapp/core/network/ConnectivityChecker.kt
+++ b/core/network/src/main/java/com/example/catalogapp/core/network/ConnectivityChecker.kt
@@ -3,10 +3,11 @@ package com.example.catalogapp.core.network
 import android.content.Context
 import android.net.ConnectivityManager
 import android.net.NetworkCapabilities
+import dagger.hilt.android.qualifiers.ApplicationContext
 import javax.inject.Inject
 
 class ConnectivityChecker @Inject constructor(
-    private val context: Context
+    @param:ApplicationContext private val context: Context
 ) {
     fun isConnected(): Boolean {
         val connectivityManager =
@@ -14,7 +15,6 @@ class ConnectivityChecker @Inject constructor(
         val network = connectivityManager.activeNetwork ?: return false
         val capabilities =
             connectivityManager.getNetworkCapabilities(network) ?: return false
-
         return capabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
     }
 }
diff --git a/core/network/src/main/java/com/example/catalogapp/core/network/NetworkModule.kt b/core/network/src/main/java/com/example/catalogapp/core/network/NetworkModule.kt
index d67c960..fc30d02 100644
--- a/core/network/src/main/java/com/example/catalogapp/core/network/NetworkModule.kt
+++ b/core/network/src/main/java/com/example/catalogapp/core/network/NetworkModule.kt
@@ -24,7 +24,7 @@ object NetworkModule {
     fun provideLoggingInterceptor(): HttpLoggingInterceptor =
         HttpLoggingInterceptor().apply {
             level = if (BuildConfig.DEBUG) {
-                HttpLoggingInterceptor.Level.BODY
+                HttpLoggingInterceptor.Level.BASIC
             } else {
                 HttpLoggingInterceptor.Level.NONE
             }
diff --git a/data/product/.gitignore b/data/product/.gitignore
new file mode 100644
index 0000000..42afabf
--- /dev/null
+++ b/data/product/.gitignore
@@ -0,0 +1 @@
+/build
\ No newline at end of file
diff --git a/data/product/build.gradle.kts b/data/product/build.gradle.kts
new file mode 100644
index 0000000..a40fbde
--- /dev/null
+++ b/data/product/build.gradle.kts
@@ -0,0 +1,91 @@
+plugins {
+    alias(libs.plugins.android.library)
+    alias(libs.plugins.hilt)
+    alias(libs.plugins.ksp)
+    alias(libs.plugins.detekt)
+    jacoco
+}
+
+android {
+    namespace = "com.example.catalogapp.data.product"
+    compileSdk {
+        version = release(36) {
+            minorApiLevel = 1
+        }
+    }
+
+    defaultConfig {
+        minSdk = 24
+
+        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+        consumerProguardFiles("consumer-rules.pro")
+    }
+
+    buildTypes {
+        release {
+            isMinifyEnabled = false
+            proguardFiles(
+                getDefaultProguardFile("proguard-android-optimize.txt"),
+                "proguard-rules.pro"
+            )
+        }
+    }
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
+    }
+}
+
+// Tell Room where to export schema files
+ksp {
+    arg("room.schemaLocation", "$projectDir/schemas")
+}
+
+detekt {
+    config.setFrom(files("$rootDir/config/detekt/detekt.yml"))
+    buildUponDefaultConfig = true
+    source.setFrom("src/main/java")
+}
+
+dependencies {
+    implementation(libs.androidx.core.ktx)
+    implementation(libs.androidx.appcompat)
+    implementation(libs.material)
+    // Domain contract this module implements
+    implementation(project(":domain:product"))
+
+    // Network layer — fetches DTOs
+    implementation(project(":core:network"))
+
+    // Common types — Result, UiState
+    implementation(project(":core:common"))
+
+    // Room — local cache
+    implementation(libs.room.runtime)
+    implementation(libs.room.ktx)
+    implementation(libs.core.ktx)
+    ksp(libs.room.compiler)
+
+    // Hilt
+    implementation(libs.hilt.android)
+    ksp(libs.hilt.compiler)
+
+    // Coroutines
+    implementation(libs.kotlinx.coroutines.android)
+
+    implementation(libs.retrofit.core)
+    implementation(libs.gson)
+
+    implementation(libs.androidx.work.runtime.ktx)
+    implementation(libs.hilt.work)
+    ksp(libs.hilt.work.compiler)
+
+    testImplementation(libs.junit)
+    testImplementation(libs.mockk)
+    testImplementation(libs.kotlinx.coroutines.test)
+    testImplementation(libs.retrofit.core)
+    testImplementation(libs.okhttp.core)
+    testImplementation(libs.androidx.work.testing)
+    androidTestImplementation(libs.androidx.junit)
+    androidTestImplementation(libs.androidx.espresso.core)
+}
diff --git a/data/product/consumer-rules.pro b/data/product/consumer-rules.pro
new file mode 100644
index 0000000..e69de29
diff --git a/data/product/proguard-rules.pro b/data/product/proguard-rules.pro
new file mode 100644
index 0000000..481bb43
--- /dev/null
+++ b/data/product/proguard-rules.pro
@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile
\ No newline at end of file
diff --git a/data/product/schemas/com.example.catalogapp.data.product.local.CatalogDatabase/1.json b/data/product/schemas/com.example.catalogapp.data.product.local.CatalogDatabase/1.json
new file mode 100644
index 0000000..400c233
--- /dev/null
+++ b/data/product/schemas/com.example.catalogapp.data.product.local.CatalogDatabase/1.json
@@ -0,0 +1,79 @@
+{
+  "formatVersion": 1,
+  "database": {
+    "version": 1,
+    "identityHash": "8430b94435aa3a15b79618d55c189157",
+    "entities": [
+      {
+        "tableName": "products",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` INTEGER NOT NULL, `title` TEXT NOT NULL, `price` REAL NOT NULL, `description` TEXT NOT NULL, `category` TEXT NOT NULL, `imageUrl` TEXT NOT NULL, `rating` REAL NOT NULL, `ratingCount` INTEGER NOT NULL, `cachedAt` INTEGER NOT NULL, PRIMARY KEY(`id`))",
+        "fields": [
+          {
+            "fieldPath": "id",
+            "columnName": "id",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "title",
+            "columnName": "title",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "price",
+            "columnName": "price",
+            "affinity": "REAL",
+            "notNull": true
+          },
+          {
+            "fieldPath": "description",
+            "columnName": "description",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "category",
+            "columnName": "category",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "imageUrl",
+            "columnName": "imageUrl",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "rating",
+            "columnName": "rating",
+            "affinity": "REAL",
+            "notNull": true
+          },
+          {
+            "fieldPath": "ratingCount",
+            "columnName": "ratingCount",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "cachedAt",
+            "columnName": "cachedAt",
+            "affinity": "INTEGER",
+            "notNull": true
+          }
+        ],
+        "primaryKey": {
+          "autoGenerate": false,
+          "columnNames": [
+            "id"
+          ]
+        }
+      }
+    ],
+    "setupQueries": [
+      "CREATE TABLE IF NOT EXISTS room_master_table (id INTEGER PRIMARY KEY,identity_hash TEXT)",
+      "INSERT OR REPLACE INTO room_master_table (id,identity_hash) VALUES(42, '8430b94435aa3a15b79618d55c189157')"
+    ]
+  }
+}
\ No newline at end of file
diff --git a/data/product/src/androidTest/java/com/example/catalogapp/data/product/ExampleInstrumentedTest.kt b/data/product/src/androidTest/java/com/example/catalogapp/data/product/ExampleInstrumentedTest.kt
new file mode 100644
index 0000000..f24a5b7
--- /dev/null
+++ b/data/product/src/androidTest/java/com/example/catalogapp/data/product/ExampleInstrumentedTest.kt
@@ -0,0 +1,24 @@
+package com.example.catalogapp.data.product
+
+import androidx.test.platform.app.InstrumentationRegistry
+import androidx.test.ext.junit.runners.AndroidJUnit4
+
+import org.junit.Test
+import org.junit.runner.RunWith
+
+import org.junit.Assert.*
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+@RunWith(AndroidJUnit4::class)
+class ExampleInstrumentedTest {
+    @Test
+    fun useAppContext() {
+        // Context of the app under test.
+        val appContext = InstrumentationRegistry.getInstrumentation().targetContext
+        assertEquals("com.example.catalogapp.data.product.test", appContext.packageName)
+    }
+}
diff --git a/data/product/src/main/AndroidManifest.xml b/data/product/src/main/AndroidManifest.xml
new file mode 100644
index 0000000..8bdb7e1
--- /dev/null
+++ b/data/product/src/main/AndroidManifest.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+</manifest>
diff --git a/data/product/src/main/java/com/example/catalogapp/data/product/di/DatabaseModule.kt b/data/product/src/main/java/com/example/catalogapp/data/product/di/DatabaseModule.kt
new file mode 100644
index 0000000..cacb435
--- /dev/null
+++ b/data/product/src/main/java/com/example/catalogapp/data/product/di/DatabaseModule.kt
@@ -0,0 +1,34 @@
+package com.example.catalogapp.data.product.di
+
+import android.content.Context
+import androidx.room.Room
+import com.example.catalogapp.data.product.local.CatalogDatabase
+import com.example.catalogapp.data.product.local.dao.ProductDao
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.android.qualifiers.ApplicationContext
+import dagger.hilt.components.SingletonComponent
+import javax.inject.Singleton
+
+@Module
+@InstallIn(SingletonComponent::class)
+object DatabaseModule {
+
+    @Provides
+    @Singleton
+    fun provideCatalogDatabase(
+        @ApplicationContext context: Context
+    ): CatalogDatabase = Room.databaseBuilder(
+        context,
+        CatalogDatabase::class.java,
+        "catalog_database"
+    )
+        .fallbackToDestructiveMigration(dropAllTables = true)
+        .build()
+
+    @Provides
+    @Singleton
+    fun provideProductDao(database: CatalogDatabase): ProductDao =
+        database.productDao()
+}
diff --git a/data/product/src/main/java/com/example/catalogapp/data/product/di/RepositoryModule.kt b/data/product/src/main/java/com/example/catalogapp/data/product/di/RepositoryModule.kt
new file mode 100644
index 0000000..b752a75
--- /dev/null
+++ b/data/product/src/main/java/com/example/catalogapp/data/product/di/RepositoryModule.kt
@@ -0,0 +1,20 @@
+package com.example.catalogapp.data.product.di
+
+import com.example.catalogapp.data.product.repository.ProductRepositoryImpl
+import com.example.catalogapp.domain.product.ProductRepository
+import dagger.Binds
+import dagger.Module
+import dagger.hilt.InstallIn
+import dagger.hilt.components.SingletonComponent
+import javax.inject.Singleton
+
+@Module
+@InstallIn(SingletonComponent::class)
+abstract class RepositoryModule {
+
+    @Binds
+    @Singleton
+    abstract fun bindProductRepository(
+        impl: ProductRepositoryImpl
+    ): ProductRepository
+}
diff --git a/data/product/src/main/java/com/example/catalogapp/data/product/di/WorkManagerModule.kt b/data/product/src/main/java/com/example/catalogapp/data/product/di/WorkManagerModule.kt
new file mode 100644
index 0000000..3b58e65
--- /dev/null
+++ b/data/product/src/main/java/com/example/catalogapp/data/product/di/WorkManagerModule.kt
@@ -0,0 +1,19 @@
+package com.example.catalogapp.data.product.di
+
+import android.content.Context
+import androidx.work.WorkManager
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.android.qualifiers.ApplicationContext
+import dagger.hilt.components.SingletonComponent
+import javax.inject.Singleton
+
+@Module
+@InstallIn(SingletonComponent::class)
+object WorkManagerModule {
+    @Provides
+    @Singleton
+    fun provideWorkManager(@ApplicationContext context: Context): WorkManager =
+        WorkManager.getInstance(context)
+}
diff --git a/data/product/src/main/java/com/example/catalogapp/data/product/local/CatalogDatabase.kt b/data/product/src/main/java/com/example/catalogapp/data/product/local/CatalogDatabase.kt
new file mode 100644
index 0000000..ac96f65
--- /dev/null
+++ b/data/product/src/main/java/com/example/catalogapp/data/product/local/CatalogDatabase.kt
@@ -0,0 +1,15 @@
+package com.example.catalogapp.data.product.local
+
+import androidx.room.Database
+import androidx.room.RoomDatabase
+import com.example.catalogapp.data.product.local.dao.ProductDao
+import com.example.catalogapp.data.product.local.entity.ProductEntity
+
+@Database(
+    entities = [ProductEntity::class],
+    version = 1,
+    exportSchema = true
+)
+abstract class CatalogDatabase : RoomDatabase() {
+    abstract fun productDao(): ProductDao
+}
diff --git a/data/product/src/main/java/com/example/catalogapp/data/product/local/dao/ProductDao.kt b/data/product/src/main/java/com/example/catalogapp/data/product/local/dao/ProductDao.kt
new file mode 100644
index 0000000..99362c9
--- /dev/null
+++ b/data/product/src/main/java/com/example/catalogapp/data/product/local/dao/ProductDao.kt
@@ -0,0 +1,26 @@
+package com.example.catalogapp.data.product.local.dao
+
+import androidx.room.Dao
+import androidx.room.Insert
+import androidx.room.OnConflictStrategy
+import androidx.room.Query
+import com.example.catalogapp.data.product.local.entity.ProductEntity
+import kotlinx.coroutines.flow.Flow
+
+@Dao
+interface ProductDao {
+    @Query("SELECT * FROM products ORDER BY title ASC")
+    fun getAllProducts(): Flow<List<ProductEntity>>
+
+    @Query("SELECT * FROM products WHERE id = :id")
+    suspend fun getProductById(id: Int): ProductEntity?
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insertProducts(products: List<ProductEntity>)
+
+    @Query("DELETE FROM products")
+    suspend fun clearAll()
+
+    @Query("SELECT cachedAt FROM products ORDER BY cachedAt ASC LIMIT 1")
+    suspend fun getOldestCacheTimestamp(): Long?
+}
diff --git a/data/product/src/main/java/com/example/catalogapp/data/product/local/entity/ProductEntity.kt b/data/product/src/main/java/com/example/catalogapp/data/product/local/entity/ProductEntity.kt
new file mode 100644
index 0000000..4a0ec43
--- /dev/null
+++ b/data/product/src/main/java/com/example/catalogapp/data/product/local/entity/ProductEntity.kt
@@ -0,0 +1,18 @@
+package com.example.catalogapp.data.product.local.entity
+
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+
+@Entity(tableName = "products")
+data class ProductEntity(
+    @PrimaryKey
+    val id: Int,
+    val title: String,
+    val price: Double,
+    val description: String,
+    val category: String,
+    val imageUrl: String,
+    val rating: Float,
+    val ratingCount: Int,
+    val cachedAt: Long = System.currentTimeMillis()
+)
diff --git a/data/product/src/main/java/com/example/catalogapp/data/product/mapper/ProductMapper.kt b/data/product/src/main/java/com/example/catalogapp/data/product/mapper/ProductMapper.kt
new file mode 100644
index 0000000..ceae092
--- /dev/null
+++ b/data/product/src/main/java/com/example/catalogapp/data/product/mapper/ProductMapper.kt
@@ -0,0 +1,43 @@
+package com.example.catalogapp.data.product.mapper
+
+import com.example.catalogapp.core.network.dto.ProductDto
+import com.example.catalogapp.data.product.local.entity.ProductEntity
+import com.example.catalogapp.domain.product.Product
+
+// ─── Network DTO → Domain Model ───────────────────────────────────────────────
+fun ProductDto.toDomain(): Product = Product(
+    id = id,
+    title = title,
+    price = price,
+    description = description,
+    category = category,
+    imageUrl = imageUrl,
+    rating = rating?.rate ?: 0f
+)
+
+// ─── Network DTO → Room Entity ────────────────────────────────────────────────
+fun ProductDto.toEntity(): ProductEntity = ProductEntity(
+    id = id,
+    title = title,
+    price = price,
+    description = description,
+    category = category,
+    imageUrl = imageUrl,
+    rating = rating?.rate ?: 0f,
+    ratingCount = rating?.count ?: 0
+)
+
+// ─── Room Entity → Domain Model ───────────────────────────────────────────────
+fun ProductEntity.toDomain(): Product = Product(
+    id = id,
+    title = title,
+    price = price,
+    description = description,
+    category = category,
+    imageUrl = imageUrl,
+    rating = rating
+)
+
+// ─── List extensions ──────────────────────────────────────────────────────────
+fun List<ProductDto>.toEntityList(): List<ProductEntity> = map { it.toEntity() }
+fun List<ProductEntity>.toDomainList(): List<Product> = map { it.toDomain() }
diff --git a/data/product/src/main/java/com/example/catalogapp/data/product/repository/ProductRepositoryImpl.kt b/data/product/src/main/java/com/example/catalogapp/data/product/repository/ProductRepositoryImpl.kt
new file mode 100644
index 0000000..15afc25
--- /dev/null
+++ b/data/product/src/main/java/com/example/catalogapp/data/product/repository/ProductRepositoryImpl.kt
@@ -0,0 +1,105 @@
+package com.example.catalogapp.data.product.repository
+
+import com.example.catalogapp.core.network.ConnectivityChecker
+import com.example.catalogapp.core.network.NetworkError
+import com.example.catalogapp.core.network.api.ProductApiService
+import com.example.catalogapp.data.product.local.dao.ProductDao
+import com.example.catalogapp.data.product.mapper.toDomain
+import com.example.catalogapp.data.product.mapper.toDomainList
+import com.example.catalogapp.data.product.mapper.toEntityList
+import com.example.catalogapp.domain.product.Product
+import com.example.catalogapp.domain.product.ProductRepository
+import com.example.catalogapp.domain.product.SyncError
+import com.example.catalogapp.domain.product.SyncResult
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.catch
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.onStart
+import java.io.IOException
+import java.net.SocketTimeoutException
+import javax.inject.Inject
+import retrofit2.HttpException
+
+class ProductRepositoryImpl @Inject constructor(
+    private val apiService: ProductApiService,
+    private val productDao: ProductDao,
+    private val connectivityChecker: ConnectivityChecker
+) : ProductRepository {
+
+    companion object {
+        // Cache is considered stale after 30 minutes
+        private const val CACHE_THRESHOLD_MS = 30 * 60 * 1000L
+    }
+
+    override fun getProducts(): Flow<List<Product>> {
+        return productDao.getAllProducts()
+            .map { entities -> entities.toDomainList() }
+            .onStart {
+                // On first collection, decide whether to refresh from network
+                if (shouldRefreshCache()) {
+                    refreshProducts()
+                }
+            }
+            .catch { _ ->
+                // Room Flow errors are rare but handle defensively
+                emit(emptyList())
+            }
+    }
+
+    override suspend fun getProductById(id: Int): Product? {
+        return productDao.getProductById(id)?.toDomain()
+            ?: fetchProductByIdFromNetwork(id)
+    }
+
+    override suspend fun syncProducts(): SyncResult = refreshProducts()
+    // ─── Private helpers ──────────────────────────────────────────────────────
+
+    private suspend fun shouldRefreshCache(): Boolean {
+        val oldestTimestamp = productDao.getOldestCacheTimestamp() ?: return true
+        return System.currentTimeMillis() - oldestTimestamp > CACHE_THRESHOLD_MS
+    }
+
+    // refreshProducts() becomes the single source of truth for both callers
+    private suspend fun refreshProducts(): SyncResult {
+        if (!connectivityChecker.isConnected()) {
+            return SyncResult.Error(SyncError.NoInternet)
+        }
+        return try {
+            val products = apiService.getProducts()
+            productDao.clearAll()
+            productDao.insertProducts(products.toEntityList())
+            SyncResult.Success
+        } catch (e: SocketTimeoutException) {
+            logError(NetworkError.Timeout, e)
+            SyncResult.Error(SyncError.Timeout)
+        } catch (e: IOException) {
+            logError(NetworkError.NoInternet, e)
+            SyncResult.Error(SyncError.NoInternet)
+        } catch (e: HttpException) {
+            logError(NetworkError.ServerError(e.code(), e.message()), e)
+            SyncResult.Error(SyncError.ServerError(e.code(), e.message()))
+        }
+    }
+
+    private suspend fun fetchProductByIdFromNetwork(id: Int): Product? {
+        if (!connectivityChecker.isConnected()) return null
+        return try {
+            apiService.getProductById(id).toDomain()
+        } catch (e: SocketTimeoutException) {
+            logError(NetworkError.Timeout, e)
+            null
+        } catch (e: IOException) {
+            logError(NetworkError.NoInternet, e)
+            null
+        } catch (e: HttpException) {
+            logError(NetworkError.ServerError(e.code(), e.message()), e)
+            null
+        }
+    }
+
+    private fun logError(networkError: NetworkError, cause: Throwable) {
+        // In a real production app this would go to Firebase Crashlytics or Timber
+        // For now: structured logging so the exception is not silently swallowed
+        println("NetworkError: ${networkError::class.simpleName} caused by: ${cause.message}")
+    }
+}
diff --git a/data/product/src/main/java/com/example/catalogapp/data/product/sync/SyncScheduler.kt b/data/product/src/main/java/com/example/catalogapp/data/product/sync/SyncScheduler.kt
new file mode 100644
index 0000000..e388186
--- /dev/null
+++ b/data/product/src/main/java/com/example/catalogapp/data/product/sync/SyncScheduler.kt
@@ -0,0 +1,46 @@
+package com.example.catalogapp.data.product.sync
+
+import androidx.work.BackoffPolicy
+import androidx.work.Constraints
+import androidx.work.ExistingPeriodicWorkPolicy
+import androidx.work.NetworkType
+import androidx.work.PeriodicWorkRequestBuilder
+import androidx.work.WorkManager
+import com.example.catalogapp.data.product.worker.ProductSyncWorker
+import java.util.concurrent.TimeUnit
+import javax.inject.Inject
+
+class SyncScheduler @Inject constructor(
+    private val workManager: WorkManager
+) {
+    fun schedulePeriodicSync() {
+        val constraints = Constraints.Builder()
+            .setRequiredNetworkType(NetworkType.UNMETERED)
+            .setRequiresBatteryNotLow(true)
+            .build()
+
+        val syncRequest = PeriodicWorkRequestBuilder<ProductSyncWorker>(
+            repeatInterval = SYNC_INTERVAL_HOURS,
+            repeatIntervalTimeUnit = TimeUnit.HOURS
+        )
+            .setConstraints(constraints)
+            .setBackoffCriteria(BackoffPolicy.EXPONENTIAL, BACKOFF_DELAY_MINUTES, TimeUnit.MINUTES)
+            .addTag(ProductSyncWorker.WORK_NAME)
+            .build()
+
+        workManager.enqueueUniquePeriodicWork(
+            ProductSyncWorker.WORK_NAME,
+            ExistingPeriodicWorkPolicy.KEEP,
+            syncRequest
+        )
+    }
+
+    fun cancelSync() {
+        workManager.cancelUniqueWork(ProductSyncWorker.WORK_NAME)
+    }
+
+    companion object {
+        private const val SYNC_INTERVAL_HOURS = 6L
+        private const val BACKOFF_DELAY_MINUTES = 15L
+    }
+}
diff --git a/data/product/src/main/java/com/example/catalogapp/data/product/worker/ProductSyncWorker.kt b/data/product/src/main/java/com/example/catalogapp/data/product/worker/ProductSyncWorker.kt
new file mode 100644
index 0000000..898b820
--- /dev/null
+++ b/data/product/src/main/java/com/example/catalogapp/data/product/worker/ProductSyncWorker.kt
@@ -0,0 +1,27 @@
+package com.example.catalogapp.data.product.worker
+
+import android.content.Context
+import androidx.hilt.work.HiltWorker
+import androidx.work.CoroutineWorker
+import androidx.work.WorkerParameters
+import com.example.catalogapp.domain.product.ProductRepository
+import dagger.assisted.Assisted
+import dagger.assisted.AssistedInject
+
+@HiltWorker
+class ProductSyncWorker @AssistedInject constructor(
+    @Assisted context: Context,
+    @Assisted workerParams: WorkerParameters,
+    private val productRepository: ProductRepository
+) : CoroutineWorker(context, workerParams) {
+
+    override suspend fun doWork(): Result =
+        productRepository.syncProducts().toWorkerResult(runAttemptCount)
+
+    companion object {
+        const val WORK_NAME = "ProductSyncWorker"
+    }
+}
+
+
+
diff --git a/data/product/src/main/java/com/example/catalogapp/data/product/worker/SyncResultMapper.kt b/data/product/src/main/java/com/example/catalogapp/data/product/worker/SyncResultMapper.kt
new file mode 100644
index 0000000..30f19d5
--- /dev/null
+++ b/data/product/src/main/java/com/example/catalogapp/data/product/worker/SyncResultMapper.kt
@@ -0,0 +1,28 @@
+package com.example.catalogapp.data.product.worker
+
+import androidx.work.ListenableWorker.Result
+import com.example.catalogapp.domain.product.SyncError
+import com.example.catalogapp.domain.product.SyncResult
+
+/**
+ * Pure mapping from domain SyncResult to WorkManager's Result.
+ * No coroutines, no Android framework, no WorkManager instantiation —
+ * testable with plain JUnit in milliseconds.
+ */
+internal fun SyncResult.toWorkerResult(runAttemptCount: Int): Result = when (this) {
+    is SyncResult.Success -> Result.success()
+    is SyncResult.Error -> when (val error = reason) {
+        is SyncError.Timeout,
+        is SyncError.NoInternet -> retryOrFail(runAttemptCount)
+
+        is SyncError.ServerError ->
+            if (error.code in RETRYABLE_HTTP_CODES) retryOrFail(runAttemptCount) else Result.failure()
+    }
+}
+
+private fun retryOrFail(runAttemptCount: Int): Result =
+    if (runAttemptCount < MAX_RETRY_ATTEMPTS) Result.retry() else Result.failure()
+
+private const val MAX_RETRY_ATTEMPTS = 3
+private val RETRYABLE_HTTP_CODES = 500..599
+
diff --git a/data/product/src/test/java/com/example/catalogapp/data/product/ExampleUnitTest.kt b/data/product/src/test/java/com/example/catalogapp/data/product/ExampleUnitTest.kt
new file mode 100644
index 0000000..4776462
--- /dev/null
+++ b/data/product/src/test/java/com/example/catalogapp/data/product/ExampleUnitTest.kt
@@ -0,0 +1,17 @@
+package com.example.catalogapp.data.product
+
+import org.junit.Test
+
+import org.junit.Assert.*
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+class ExampleUnitTest {
+    @Test
+    fun addition_isCorrect() {
+        assertEquals(4, 2 + 2)
+    }
+}
diff --git a/data/product/src/test/java/com/example/catalogapp/data/product/repository/ProductRepositoryImplTest.kt b/data/product/src/test/java/com/example/catalogapp/data/product/repository/ProductRepositoryImplTest.kt
new file mode 100644
index 0000000..fa27f22
--- /dev/null
+++ b/data/product/src/test/java/com/example/catalogapp/data/product/repository/ProductRepositoryImplTest.kt
@@ -0,0 +1,246 @@
+package com.example.catalogapp.data.product.repository
+
+import com.example.catalogapp.core.network.ConnectivityChecker
+import com.example.catalogapp.core.network.api.ProductApiService
+import com.example.catalogapp.core.network.dto.ProductDto
+import com.example.catalogapp.core.network.dto.RatingDto
+import com.example.catalogapp.data.product.local.dao.ProductDao
+import com.example.catalogapp.data.product.local.entity.ProductEntity
+import com.example.catalogapp.domain.product.SyncError
+import com.example.catalogapp.domain.product.SyncResult
+import io.mockk.coEvery
+import io.mockk.coVerify
+import io.mockk.every
+import io.mockk.mockk
+import junit.framework.TestCase.assertEquals
+import junit.framework.TestCase.assertNull
+import junit.framework.TestCase.assertTrue
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.flowOf
+import kotlinx.coroutines.test.runTest
+import okhttp3.ResponseBody.Companion.toResponseBody
+import org.junit.Before
+import org.junit.Test
+import retrofit2.HttpException
+import retrofit2.Response
+import java.net.SocketTimeoutException
+
+class ProductRepositoryImplTest {
+    private val apiService: ProductApiService = mockk()
+    private val productDao: ProductDao = mockk()
+    private val connectivityChecker: ConnectivityChecker = mockk()
+
+    private lateinit var repository: ProductRepositoryImpl
+
+    private val fakeEntity = ProductEntity(
+        id = 1,
+        title = "Gold Ring",
+        price = 4500.0,
+        description = "22K gold ring",
+        category = "rings",
+        imageUrl = "https://example.com/ring.png",
+        rating = 4.5f,
+        ratingCount = 100,
+        cachedAt = System.currentTimeMillis()
+    )
+
+    private val fakeDto = ProductDto(
+        id = 2,
+        title = "Silver Necklace",
+        price = 2500.0,
+        description = "Pure silver necklace",
+        category = "necklaces",
+        imageUrl = "https://example.com/necklace.png",
+        rating = RatingDto(rate = 4.2f, count = 50)
+    )
+
+    @Before
+    fun setUp() {
+        repository = ProductRepositoryImpl(apiService, productDao, connectivityChecker)
+    }
+
+    @Test
+    fun `getProducts returns mapped domain list from Room when cache is fresh`() = runTest {
+        // Arrange — cache is fresh (cachedAt is now)
+        val freshTimestamp = System.currentTimeMillis()
+        every { productDao.getAllProducts() } returns flowOf(listOf(fakeEntity))
+        coEvery { productDao.getOldestCacheTimestamp() } returns freshTimestamp
+
+        // Act
+        val result = repository.getProducts().first()
+
+        // Assert — entity mapped to domain correctly
+        assertEquals(1, result.size)
+        assertEquals("Gold Ring", result[0].title)
+        assertEquals(4500.0, result[0].price, 0.0)
+    }
+
+    @Test
+    fun `getProducts triggers network refresh when cache is stale`() = runTest {
+        // Arrange — cache is stale (older than 30 minutes)
+        val staleTimestamp = System.currentTimeMillis() - (31 * 60 * 1000L)
+        every { productDao.getAllProducts() } returns flowOf(listOf(fakeEntity))
+        coEvery { productDao.getOldestCacheTimestamp() } returns staleTimestamp
+        every { connectivityChecker.isConnected() } returns true
+        coEvery { apiService.getProducts() } returns listOf(fakeDto)
+        coEvery { productDao.clearAll() } returns Unit
+        coEvery { productDao.insertProducts(any()) } returns Unit
+
+        // Act
+        repository.getProducts().first()
+
+        // Assert — network was called and DAO was updated
+        coVerify { apiService.getProducts() }
+        coVerify { productDao.clearAll() }
+        coVerify { productDao.insertProducts(any()) }
+    }
+
+    @Test
+    fun `getProducts does not call network when offline even if cache is stale`() = runTest {
+        // Arrange — stale cache + no internet
+        val staleTimestamp = System.currentTimeMillis() - (31 * 60 * 1000L)
+        every { productDao.getAllProducts() } returns flowOf(listOf(fakeEntity))
+        coEvery { productDao.getOldestCacheTimestamp() } returns staleTimestamp
+        every { connectivityChecker.isConnected() } returns false
+
+        // Act
+        repository.getProducts().first()
+
+        // Assert — network was never called despite stale cache
+        coVerify(exactly = 0) { apiService.getProducts() }
+    }
+
+    @Test
+    fun `getProductById returns cached entity when available`() = runTest {
+        // Arrange
+        coEvery { productDao.getProductById(1) } returns fakeEntity
+
+        // Act
+        val result = repository.getProductById(1)
+
+        // Assert
+        assertEquals("Gold Ring", result?.title)
+        // Network should never have been called
+        coVerify(exactly = 0) { apiService.getProductById(any()) }
+    }
+
+    @Test
+    fun `getProductById fetches from network when not in cache and connected`() = runTest {
+        // Arrange — not in cache, connected
+        coEvery { productDao.getProductById(2) } returns null
+        every { connectivityChecker.isConnected() } returns true
+        coEvery { apiService.getProductById(2) } returns fakeDto
+
+        // Act
+        val result = repository.getProductById(2)
+
+        // Assert
+        assertEquals("Silver Necklace", result?.title)
+        coVerify { apiService.getProductById(2) }
+    }
+
+    @Test
+    fun `getProductById returns null when not in cache and offline`() = runTest {
+        // Arrange — not in cache, offline
+        coEvery { productDao.getProductById(99) } returns null
+        every { connectivityChecker.isConnected() } returns false
+
+        // Act
+        val result = repository.getProductById(99)
+
+        // Assert
+        assertNull(result)
+        coVerify(exactly = 0) { apiService.getProductById(any()) }
+    }
+
+    @Test
+    fun `refreshProducts handles SocketTimeoutException silently and serves stale cache`() =
+        runTest {
+            // Arrange — stale cache, connected, but network times out
+            val staleTimestamp = System.currentTimeMillis() - (31 * 60 * 1000L)
+            every { productDao.getAllProducts() } returns flowOf(listOf(fakeEntity))
+            coEvery { productDao.getOldestCacheTimestamp() } returns staleTimestamp
+            every { connectivityChecker.isConnected() } returns true
+            coEvery { apiService.getProducts() } throws SocketTimeoutException()
+            coEvery { productDao.clearAll() } returns Unit
+
+            // Act — should not throw, stale cache served silently
+            val result = repository.getProducts().first()
+
+            // Assert — user still sees cached data, no crash
+            assertEquals(1, result.size)
+            assertEquals("Gold Ring", result[0].title)
+        }
+
+    @Test
+    fun `refreshProducts handles HttpException silently and serves stale cache`() = runTest {
+        // Arrange — stale cache, connected, but server returns 500
+        val staleTimestamp = System.currentTimeMillis() - (31 * 60 * 1000L)
+        every { productDao.getAllProducts() } returns flowOf(listOf(fakeEntity))
+        coEvery { productDao.getOldestCacheTimestamp() } returns staleTimestamp
+        every { connectivityChecker.isConnected() } returns true
+        coEvery { apiService.getProducts() } throws HttpException(
+            Response.error<Any>(
+                500,
+                "Internal Server Error".toResponseBody(null)
+            )
+        )
+        coEvery { productDao.clearAll() } returns Unit
+
+        // Act — should not throw, stale cache served silently
+        val result = repository.getProducts().first()
+
+        // Assert — user still sees cached data, no crash
+        assertEquals(1, result.size)
+    }
+
+    @Test
+    fun `mapper handles null rating defensively and defaults to zero`() = runTest {
+        // Arrange — DTO with null rating (real FakeStore API edge case)
+        val dtoWithNullRating = ProductDto(
+            id = 3,
+            title = "Test Product",
+            price = 100.0,
+            description = "Test description",
+            category = "test",
+            imageUrl = "https://example.com/test.png",
+            rating = null
+        )
+        coEvery { productDao.getProductById(3) } returns null
+        every { connectivityChecker.isConnected() } returns true
+        coEvery { apiService.getProductById(3) } returns dtoWithNullRating
+
+        // Act
+        val result = repository.getProductById(3)
+
+        // Assert — rating defaults to 0f, no NullPointerException
+        assertEquals(0f, result?.rating)
+        assertEquals("Test Product", result?.title)
+    }
+
+    @Test
+    fun `syncProducts returns Success when sync completes`() = runTest {
+        every { connectivityChecker.isConnected() } returns true
+        coEvery { apiService.getProducts() } returns listOf(fakeDto)
+        coEvery { productDao.clearAll() } returns Unit
+        coEvery { productDao.insertProducts(any()) } returns Unit
+
+        val result = repository.syncProducts()
+
+        assertTrue(result is SyncResult.Success)
+        coVerify { apiService.getProducts() }
+        coVerify { productDao.clearAll() }
+        coVerify { productDao.insertProducts(any()) }
+    }
+
+    @Test
+    fun `syncProducts returns Error NoInternet when disconnected`() = runTest {
+        every { connectivityChecker.isConnected() } returns false
+
+        val result = repository.syncProducts()
+
+        assertTrue(result is SyncResult.Error)
+        assertTrue((result as SyncResult.Error).reason is SyncError.NoInternet)
+        coVerify(exactly = 0) { apiService.getProducts() }
+    }
+}
diff --git a/data/product/src/test/java/com/example/catalogapp/data/product/worker/SyncResultMapperTest.kt b/data/product/src/test/java/com/example/catalogapp/data/product/worker/SyncResultMapperTest.kt
new file mode 100644
index 0000000..c3d6795
--- /dev/null
+++ b/data/product/src/test/java/com/example/catalogapp/data/product/worker/SyncResultMapperTest.kt
@@ -0,0 +1,48 @@
+package com.example.catalogapp.data.product.worker
+
+import androidx.work.ListenableWorker.Result
+import com.example.catalogapp.domain.product.SyncError
+import com.example.catalogapp.domain.product.SyncResult
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class SyncResultMapperTest {
+
+    @Test
+    fun `Success maps to Result Success`() {
+        val result = SyncResult.Success.toWorkerResult(runAttemptCount = 0)
+        assertTrue(result is Result.Success)
+    }
+
+    @Test
+    fun `Timeout retries under max attempts`() {
+        val result = SyncResult.Error(SyncError.Timeout).toWorkerResult(runAttemptCount = 1)
+        assertTrue(result is Result.Retry)
+    }
+
+    @Test
+    fun `Timeout fails after max attempts exhausted`() {
+        val result = SyncResult.Error(SyncError.Timeout).toWorkerResult(runAttemptCount = 3)
+        assertTrue(result is Result.Failure)
+    }
+
+    @Test
+    fun `NoInternet retries under max attempts`() {
+        val result = SyncResult.Error(SyncError.NoInternet).toWorkerResult(runAttemptCount = 0)
+        assertTrue(result is Result.Retry)
+    }
+
+    @Test
+    fun `5xx server error retries`() {
+        val result = SyncResult.Error(SyncError.ServerError(503, "Unavailable"))
+            .toWorkerResult(runAttemptCount = 0)
+        assertTrue(result is Result.Retry)
+    }
+
+    @Test
+    fun `4xx server error fails fast without retry`() {
+        val result = SyncResult.Error(SyncError.ServerError(400, "Bad Request"))
+            .toWorkerResult(runAttemptCount = 0)
+        assertTrue(result is Result.Failure)
+    }
+}
\ No newline at end of file
diff --git a/domain/product/build.gradle.kts b/domain/product/build.gradle.kts
index cac33df..151371f 100644
--- a/domain/product/build.gradle.kts
+++ b/domain/product/build.gradle.kts
@@ -1,5 +1,17 @@
 plugins {
     alias(libs.plugins.kotlin.jvm)
+    jacoco
+    alias(libs.plugins.detekt)
+}
+
+jacoco {
+    toolVersion = "0.8.12"
+}
+
+detekt {
+    config.setFrom(files("$rootDir/config/detekt/detekt.yml"))
+    buildUponDefaultConfig = true
+    source.setFrom("src/main/java")
 }
 
 dependencies {
diff --git a/domain/product/src/main/java/com/example/catalogapp/domain/product/ProductRepository.kt b/domain/product/src/main/java/com/example/catalogapp/domain/product/ProductRepository.kt
index 01c7f1b..df5147f 100644
--- a/domain/product/src/main/java/com/example/catalogapp/domain/product/ProductRepository.kt
+++ b/domain/product/src/main/java/com/example/catalogapp/domain/product/ProductRepository.kt
@@ -5,4 +5,6 @@ import kotlinx.coroutines.flow.Flow
 interface ProductRepository {
     fun getProducts(): Flow<List<Product>>
     suspend fun getProductById(id: Int): Product?
+    suspend fun syncProducts(): SyncResult
 }
+
diff --git a/domain/product/src/main/java/com/example/catalogapp/domain/product/SearchProductsUseCase.kt b/domain/product/src/main/java/com/example/catalogapp/domain/product/SearchProductsUseCase.kt
new file mode 100644
index 0000000..97dae6d
--- /dev/null
+++ b/domain/product/src/main/java/com/example/catalogapp/domain/product/SearchProductsUseCase.kt
@@ -0,0 +1,14 @@
+package com.example.catalogapp.domain.product
+
+import javax.inject.Inject
+
+class SearchProductsUseCase @Inject constructor() {
+    operator fun invoke(products: List<Product>, query: String): List<Product> {
+        if (query.isBlank()) return emptyList()
+        return products.filter { product ->
+            product.title.contains(query, ignoreCase = true) ||
+                    product.category.contains(query, ignoreCase = true)
+        }
+    }
+}
+
diff --git a/domain/product/src/main/java/com/example/catalogapp/domain/product/SyncResult.kt b/domain/product/src/main/java/com/example/catalogapp/domain/product/SyncResult.kt
new file mode 100644
index 0000000..117e139
--- /dev/null
+++ b/domain/product/src/main/java/com/example/catalogapp/domain/product/SyncResult.kt
@@ -0,0 +1,12 @@
+package com.example.catalogapp.domain.product
+
+sealed class SyncResult {
+    object Success : SyncResult()
+    data class Error(val reason: SyncError) : SyncResult()
+}
+
+sealed class SyncError {
+    object Timeout : SyncError()
+    object NoInternet : SyncError()
+    data class ServerError(val code: Int, val message: String?) : SyncError()
+}
diff --git a/domain/product/src/test/java/com/example/catalogapp/domain/product/SearchProductsUseCaseTest.kt b/domain/product/src/test/java/com/example/catalogapp/domain/product/SearchProductsUseCaseTest.kt
new file mode 100644
index 0000000..1b01bc3
--- /dev/null
+++ b/domain/product/src/test/java/com/example/catalogapp/domain/product/SearchProductsUseCaseTest.kt
@@ -0,0 +1,63 @@
+package com.example.catalogapp.domain.product
+
+import junit.framework.TestCase.assertEquals
+import junit.framework.TestCase.assertTrue
+import org.junit.Test
+
+class SearchProductsUseCaseTest {
+
+    private val useCase = SearchProductsUseCase()
+
+    private val products = listOf(
+        Product(
+            id = 1, title = "Silver Earrings", price = 120.0,
+            description = "d", category = "Jewelry", imageUrl = "", rating = 4.8f
+        ),
+        Product(
+            id = 2, title = "Running Shoes", price = 185.0,
+            description = "d", category = "Footwear", imageUrl = "", rating = 4.9f
+        ),
+        Product(
+            id = 3, title = "Gold Necklace", price = 300.0,
+            description = "d", category = "Jewelry", imageUrl = "", rating = 4.7f
+        )
+    )
+
+    @Test
+    fun `blank query returns empty list`() {
+        val result = useCase(products, "")
+        assertTrue(result.isEmpty())
+    }
+
+    @Test
+    fun `matches by title substring`() {
+        val result = useCase(products, "Earrings")
+        assertEquals(1, result.size)
+        assertEquals("Silver Earrings", result.first().title)
+    }
+
+    @Test
+    fun `matches by category substring`() {
+        val result = useCase(products, "Jewelry")
+        assertEquals(2, result.size)
+        assertTrue(result.all { it.category == "Jewelry" })
+    }
+
+    @Test
+    fun `match is case-insensitive`() {
+        val result = useCase(products, "SILVER")
+        assertEquals(1, result.size)
+    }
+
+    @Test
+    fun `no matches returns empty list`() {
+        val result = useCase(products, "nonexistent")
+        assertTrue(result.isEmpty())
+    }
+
+    @Test
+    fun `empty product list returns empty list regardless of query`() {
+        val result = useCase(emptyList(), "silver")
+        assertTrue(result.isEmpty())
+    }
+}
\ No newline at end of file
diff --git a/domain/product/src/test/java/com/example/catalogapp/domain/product/SyncResultTest.kt b/domain/product/src/test/java/com/example/catalogapp/domain/product/SyncResultTest.kt
new file mode 100644
index 0000000..25fe0a5
--- /dev/null
+++ b/domain/product/src/test/java/com/example/catalogapp/domain/product/SyncResultTest.kt
@@ -0,0 +1,18 @@
+package com.example.catalogapp.domain.product
+
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class SyncResultTest {
+    @Test
+    fun `Success is a SyncResult`() {
+        assertTrue(true)
+    }
+
+    @Test
+    fun `Error wraps SyncError correctly`() {
+        val result = SyncResult.Error(SyncError.ServerError(500, "Internal error"))
+        assertTrue(true)
+        assertTrue(result.reason is SyncError.ServerError)
+    }
+}
\ No newline at end of file
diff --git a/feature/catalog/.gitignore b/feature/catalog/.gitignore
new file mode 100644
index 0000000..42afabf
--- /dev/null
+++ b/feature/catalog/.gitignore
@@ -0,0 +1 @@
+/build
\ No newline at end of file
diff --git a/feature/catalog/build.gradle.kts b/feature/catalog/build.gradle.kts
new file mode 100644
index 0000000..7ce0e1c
--- /dev/null
+++ b/feature/catalog/build.gradle.kts
@@ -0,0 +1,77 @@
+plugins {
+    alias(libs.plugins.android.library)
+    alias(libs.plugins.kotlin.compose)
+    alias(libs.plugins.hilt)
+    alias(libs.plugins.ksp)
+    alias(libs.plugins.detekt)
+    jacoco
+}
+
+android {
+    namespace = "com.example.catalogapp.feature.catalog"
+    compileSdk = 36
+
+    defaultConfig {
+        minSdk = 24
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    buildFeatures {
+        compose = true
+    }
+}
+
+detekt {
+    config.setFrom(files("$rootDir/config/detekt/detekt.yml"))
+    buildUponDefaultConfig = true
+    source.setFrom("src/main/java")
+}
+
+dependencies {
+    // Domain — use cases and models
+    implementation(project(":domain:product"))
+
+    // Common — UiState, Result
+    implementation(project(":core:common"))
+
+    // Design system — theme, components
+    implementation(project(":core:designsystem"))
+
+    // Compose
+    implementation(platform(libs.androidx.compose.bom))
+    implementation(libs.androidx.compose.ui)
+    implementation(libs.androidx.compose.material3)
+    implementation(libs.androidx.compose.ui.tooling.preview)
+    debugImplementation(libs.androidx.compose.ui.tooling)
+
+    // Lifecycle
+    implementation(libs.androidx.lifecycle.runtime.ktx)
+
+    // Hilt
+    implementation(libs.hilt.android)
+    ksp(libs.hilt.compiler)
+
+    // Hilt Navigation Compose
+    implementation(libs.hilt.navigation.compose)
+
+    // Coroutines
+    implementation(libs.kotlinx.coroutines.android)
+
+    // Coil
+    implementation(libs.coil.compose)
+
+    implementation(libs.androidx.compose.material.icons.extended)
+
+    // Testing
+    testImplementation(libs.junit)
+    testImplementation(libs.mockk)
+    testImplementation(libs.kotlinx.coroutines.test)
+}
+
+jacoco {
+    toolVersion = "0.8.12"
+}
diff --git a/feature/catalog/consumer-rules.pro b/feature/catalog/consumer-rules.pro
new file mode 100644
index 0000000..e69de29
diff --git a/feature/catalog/proguard-rules.pro b/feature/catalog/proguard-rules.pro
new file mode 100644
index 0000000..481bb43
--- /dev/null
+++ b/feature/catalog/proguard-rules.pro
@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile
\ No newline at end of file
diff --git a/feature/catalog/src/androidTest/java/com/example/catalogapp/feature/catalog/ExampleInstrumentedTest.kt b/feature/catalog/src/androidTest/java/com/example/catalogapp/feature/catalog/ExampleInstrumentedTest.kt
new file mode 100644
index 0000000..a18dc28
--- /dev/null
+++ b/feature/catalog/src/androidTest/java/com/example/catalogapp/feature/catalog/ExampleInstrumentedTest.kt
@@ -0,0 +1,24 @@
+package com.example.catalogapp.feature.catalog
+
+import androidx.test.platform.app.InstrumentationRegistry
+import androidx.test.ext.junit.runners.AndroidJUnit4
+
+import org.junit.Test
+import org.junit.runner.RunWith
+
+import org.junit.Assert.*
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+@RunWith(AndroidJUnit4::class)
+class ExampleInstrumentedTest {
+    @Test
+    fun useAppContext() {
+        // Context of the app under test.
+        val appContext = InstrumentationRegistry.getInstrumentation().targetContext
+        assertEquals("com.example.catalogapp.feature.catalog.test", appContext.packageName)
+    }
+}
diff --git a/feature/catalog/src/main/AndroidManifest.xml b/feature/catalog/src/main/AndroidManifest.xml
new file mode 100644
index 0000000..8bdb7e1
--- /dev/null
+++ b/feature/catalog/src/main/AndroidManifest.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+</manifest>
diff --git a/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/CatalogContract.kt b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/CatalogContract.kt
new file mode 100644
index 0000000..15ff2a6
--- /dev/null
+++ b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/CatalogContract.kt
@@ -0,0 +1,51 @@
+package com.example.catalogapp.feature.catalog
+
+import com.example.catalogapp.domain.product.Product
+
+// ─── UI State — single source of truth for the catalog screen ─────────────────
+// Data class (not sealed) because multiple states can be true simultaneously:
+// isRefreshing=true while products are still visible during pull-to-refresh
+data class CatalogUiState(
+    val products: List<Product> = emptyList(),
+    val isLoading: Boolean = false,
+    val isRefreshing: Boolean = false,
+    val error: String? = null,
+    val selectedCategory: String = "All"
+) {
+    // Derived state — computed from existing state, never stored separately
+    // This prevents impossible state combinations like isLoading=true + showProducts=true
+    val showLoading: Boolean get() = isLoading && products.isEmpty()
+    val showError: Boolean get() = error != null && !isLoading && products.isEmpty()
+    val showEmpty: Boolean get() = !isLoading && error == null && products.isEmpty()
+    val showProducts: Boolean get() = products.isNotEmpty()
+
+    // Categories derived from product list — no separate state needed
+    val categories: List<String> get() = listOf("All") +
+            products.map { it.category }
+                .distinct()
+                .sorted()
+
+    // Filtered products based on selected category
+    val filteredProducts: List<Product> get() = if (selectedCategory == "All") {
+        products
+    } else {
+        products.filter { it.category == selectedCategory }
+    }
+}
+
+// ─── Intent — every possible user action, explicitly named ────────────────────
+sealed class CatalogIntent {
+    object LoadProducts : CatalogIntent()
+    object RefreshProducts : CatalogIntent()
+    object RetryLoad : CatalogIntent()
+    object SearchClicked : CatalogIntent()
+    data class SelectCategory(val category: String) : CatalogIntent()
+    data class ProductClicked(val productId: Int) : CatalogIntent()
+}
+
+// ─── Effect — one-time events, consumed once, never replayed ──────────────────
+sealed class CatalogEffect {
+    data class NavigateToDetail(val productId: Int) : CatalogEffect()
+    object NavigateToSearch : CatalogEffect()
+    data class ShowSnackbar(val message: String) : CatalogEffect()
+}
diff --git a/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/CatalogScreen.kt b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/CatalogScreen.kt
new file mode 100644
index 0000000..4fe682c
--- /dev/null
+++ b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/CatalogScreen.kt
@@ -0,0 +1,159 @@
+package com.example.catalogapp.feature.catalog
+
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Scaffold
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableIntStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+import com.example.catalogapp.domain.product.Product
+import com.example.catalogapp.feature.catalog.components.CatalogBody
+import com.example.catalogapp.feature.catalog.components.CatalogBottomBar
+import com.example.catalogapp.feature.catalog.components.CatalogFab
+import com.example.catalogapp.feature.catalog.components.CatalogTopBar
+
+private const val SEARCH_TAB_INDEX = 1
+
+// ─── Top-level screen — owns ViewModel, handles effects ───────────────────────
+@Composable
+fun CatalogScreen(
+    onNavigateToDetail: (Int) -> Unit,
+    onNavigateToSearch: () -> Unit,
+    viewModel: CatalogViewModel = hiltViewModel()
+) {
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    LaunchedEffect(Unit) {
+        viewModel.effect.collect { effect ->
+            when (effect) {
+                is CatalogEffect.NavigateToDetail -> onNavigateToDetail(effect.productId)
+                is CatalogEffect.NavigateToSearch -> onNavigateToSearch()
+                is CatalogEffect.ShowSnackbar -> {}
+            }
+        }
+    }
+    CatalogContent(
+        uiState = uiState,
+        onIntent = viewModel::processIntent
+    )
+}
+
+// ─── Stateless content composable — thin composition root ────────────────────
+// Scaffold slots (top bar, bottom bar, fab, body) each live in their own file
+// under components/, so this stays small and easy to scan (TooManyFunctions /
+// LongMethod safe by construction rather than by suppression).
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+internal fun CatalogContent(
+    uiState: CatalogUiState,
+    onIntent: (CatalogIntent) -> Unit
+) {
+    var selectedNavItem by remember { mutableIntStateOf(0) }
+
+    Scaffold(
+        topBar = {
+            CatalogTopBar(onSearchClick = { onIntent(CatalogIntent.SearchClicked) })
+        },
+        bottomBar = {
+            CatalogBottomBar(
+                selectedIndex = selectedNavItem,
+                onItemSelected = { index ->
+                    when (index) {
+                        SEARCH_TAB_INDEX -> onIntent(CatalogIntent.SearchClicked)
+                        else -> selectedNavItem =
+                            index // Home/Wishlist/Profile — visual only for now
+                    }
+                }
+            )
+        },
+        floatingActionButton = {
+            CatalogFab(onClick = { })
+        }
+    ) { paddingValues ->
+        CatalogBody(
+            uiState = uiState,
+            onIntent = onIntent,
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(paddingValues)
+        )
+    }
+}
+
+// ─── Previews ─────────────────────────────────────────────────────────────────
+@Preview(showBackground = true, name = "Catalog - Products")
+@Composable
+internal fun CatalogContentPreview() {
+    CatalogTheme {
+        CatalogContent(
+            uiState = CatalogUiState(
+                products = previewProducts,
+                selectedCategory = "All"
+            ),
+            onIntent = {}
+        )
+    }
+}
+
+@Preview(showBackground = true, name = "Catalog - Loading")
+@Composable
+internal fun CatalogLoadingPreview() {
+    CatalogTheme {
+        CatalogContent(
+            uiState = CatalogUiState(isLoading = true),
+            onIntent = {}
+        )
+    }
+}
+
+@Preview(showBackground = true, name = "Catalog - Error")
+@Composable
+internal fun CatalogErrorPreview() {
+    CatalogTheme {
+        CatalogContent(
+            uiState = CatalogUiState(
+                error = "Unable to load products."
+            ),
+            onIntent = {}
+        )
+    }
+}
+
+private val previewProducts = listOf(
+    Product(
+        1,
+        "Premium Stealth Titanium Smartwatch Series 9",
+        24999.0,
+        "Great watch",
+        "electronics",
+        "",
+        4.8f
+    ),
+    Product(
+        2,
+        "Linen Heritage Slim-Fit Kurta - Emerald",
+        3450.0,
+        "Great kurta",
+        "men's clothing",
+        "",
+        4.6f
+    ),
+    Product(
+        3,
+        "SonicFlow Noise-Cancelling Headphones",
+        18200.0,
+        "Great headphones",
+        "electronics",
+        "",
+        4.9f
+    ),
+    Product(4, "Geometric Prism Gold Earrings", 12499.0, "Great earrings", "jewelery", "", 4.5f)
+)
diff --git a/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/CatalogViewModel.kt b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/CatalogViewModel.kt
new file mode 100644
index 0000000..9ed6935
--- /dev/null
+++ b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/CatalogViewModel.kt
@@ -0,0 +1,99 @@
+package com.example.catalogapp.feature.catalog
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.example.catalogapp.domain.product.GetProductsUseCase
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.catch
+import kotlinx.coroutines.flow.receiveAsFlow
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+@HiltViewModel
+class CatalogViewModel @Inject constructor(
+    private val getProductsUseCase: GetProductsUseCase
+) : ViewModel() {
+
+    // ─── State — single StateFlow, single source of truth ─────────────────────
+    private val _uiState = MutableStateFlow(CatalogUiState())
+    val uiState: StateFlow<CatalogUiState> = _uiState.asStateFlow()
+
+    // ─── Effects — Channel for one-time events ─────────────────────────────────
+    // Channel.BUFFERED ensures effects aren't dropped if UI isn't collecting yet
+    private val _effect = Channel<CatalogEffect>(Channel.BUFFERED)
+    val effect = _effect.receiveAsFlow()
+
+    init {
+        processIntent(CatalogIntent.LoadProducts)
+    }
+
+    // ─── Single entry point for ALL user actions ───────────────────────────────
+    // This is the core MVI pattern — UI calls only this function
+    fun processIntent(intent: CatalogIntent) {
+        when (intent) {
+            is CatalogIntent.LoadProducts -> loadProducts()
+            is CatalogIntent.RefreshProducts -> refreshProducts()
+            is CatalogIntent.RetryLoad -> loadProducts()
+            is CatalogIntent.SearchClicked -> navigateToSearch()
+            is CatalogIntent.SelectCategory -> selectCategory(intent.category)
+            is CatalogIntent.ProductClicked -> navigateToDetail(intent.productId)
+        }
+    }
+
+    // ─── Private handlers ──────────────────────────────────────────────────────
+    private fun loadProducts() = fetchProducts(showAsRefresh = false)
+    private fun refreshProducts() = fetchProducts(showAsRefresh = true)
+
+    private fun fetchProducts(showAsRefresh: Boolean) {
+        viewModelScope.launch {
+            _uiState.update {
+                if (showAsRefresh) it.copy(isRefreshing = true) else it.copy(
+                    isLoading = true,
+                    error = null
+                )
+            }
+
+            getProductsUseCase()
+                .catch { exception ->
+                    _uiState.update {
+                        it.copy(
+                            isLoading = false,
+                            isRefreshing = false,
+                            error = exception.message ?: "Failed to load products"
+                        )
+                    }
+                }
+                .collect { products ->
+                    _uiState.update {
+                        it.copy(
+                            isLoading = false,
+                            isRefreshing = false,
+                            products = products,
+                            error = null
+                        )
+                    }
+                }
+        }
+    }
+
+    private fun selectCategory(category: String) {
+        _uiState.update { it.copy(selectedCategory = category) }
+    }
+
+    private fun navigateToDetail(productId: Int) {
+        viewModelScope.launch {
+            _effect.send(CatalogEffect.NavigateToDetail(productId))
+        }
+    }
+
+    private fun navigateToSearch() {
+        viewModelScope.launch {
+            _effect.send(CatalogEffect.NavigateToSearch)
+        }
+    }
+}
diff --git a/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Catalogbody.kt b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Catalogbody.kt
new file mode 100644
index 0000000..6122083
--- /dev/null
+++ b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Catalogbody.kt
@@ -0,0 +1,104 @@
+package com.example.catalogapp.feature.catalog.components
+
+import androidx.compose.animation.AnimatedContent
+import androidx.compose.animation.core.tween
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+import androidx.compose.animation.togetherWith
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.pulltorefresh.PullToRefreshBox
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import com.example.catalogapp.core.designsystem.components.CatalogEmptyState
+import com.example.catalogapp.core.designsystem.components.CatalogErrorState
+import com.example.catalogapp.core.designsystem.components.CategoryChipRowSkeleton
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+import com.example.catalogapp.feature.catalog.CatalogIntent
+import com.example.catalogapp.feature.catalog.CatalogUiState
+
+private const val CROSSFADE_DURATION_MS = 400
+
+// Represents WHICH content state we're in — used as the AnimatedContent key.
+// Without this, AnimatedContent can't distinguish "loading -> success" from
+// "loading -> error", since both are just showLoading going true -> false.
+private enum class CatalogContentState {
+    Loading, Error, Empty, Products
+}
+
+private fun CatalogUiState.contentState(): CatalogContentState = when {
+    showLoading -> CatalogContentState.Loading
+    showError -> CatalogContentState.Error
+    showEmpty -> CatalogContentState.Empty
+    else -> CatalogContentState.Products
+}
+
+// ─── Body — pull-to-refresh + category chips + content states ────────────────
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+internal fun CatalogBody(
+    uiState: CatalogUiState,
+    onIntent: (CatalogIntent) -> Unit,
+    modifier: Modifier = Modifier
+) {
+    val spacing = CatalogTheme.spacing
+    val state = uiState.contentState()
+
+    PullToRefreshBox(
+        isRefreshing = uiState.isRefreshing,
+        onRefresh = {
+            onIntent(CatalogIntent.RefreshProducts)
+        },
+        modifier = modifier
+    ) {
+        Column(modifier = Modifier.fillMaxSize()) {
+            when (state) {
+                CatalogContentState.Loading -> CategoryChipRowSkeleton(
+                    modifier = Modifier.padding(horizontal = spacing.md, vertical = spacing.md)
+                )
+
+                else -> if (uiState.categories.size > 1) {
+                    CategoryChips(
+                        categories = uiState.categories,
+                        selectedCategory = uiState.selectedCategory,
+                        onCategorySelected = { category ->
+                            onIntent(
+                                CatalogIntent.SelectCategory(
+                                    category
+                                )
+                            )
+                        }
+                    )
+                }
+            }
+
+            AnimatedContent(
+                targetState = uiState.contentState(),
+                transitionSpec = {
+                    fadeIn(animationSpec = tween(CROSSFADE_DURATION_MS)) togetherWith
+                            fadeOut(animationSpec = tween(CROSSFADE_DURATION_MS))
+                },
+                label = "catalog_content_crossfade"
+            ) { state ->
+                when (state) {
+                    CatalogContentState.Loading -> ProductGridSkeleton()
+                    CatalogContentState.Error -> CatalogErrorState(
+                        message = uiState.error ?: "Unknown error",
+                        onRetry = { onIntent(CatalogIntent.RetryLoad) }
+                    )
+
+                    CatalogContentState.Empty -> CatalogEmptyState(
+                        message = "No products available right now."
+                    )
+
+                    CatalogContentState.Products -> ProductGrid(
+                        products = uiState.filteredProducts,
+                        onProductClick = { id -> onIntent(CatalogIntent.ProductClicked(id)) }
+                    )
+                }
+            }
+        }
+    }
+}
diff --git a/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Catalogbottombar.kt b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Catalogbottombar.kt
new file mode 100644
index 0000000..8b53b3a
--- /dev/null
+++ b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Catalogbottombar.kt
@@ -0,0 +1,74 @@
+package com.example.catalogapp.feature.catalog.components
+
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Favorite
+import androidx.compose.material.icons.filled.FavoriteBorder
+import androidx.compose.material.icons.filled.Home
+import androidx.compose.material.icons.filled.Menu
+import androidx.compose.material.icons.filled.Search
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.NavigationBar
+import androidx.compose.material3.NavigationBarItem
+import androidx.compose.material3.NavigationBarItemDefaults
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.components.rememberDebouncedOnClick
+
+private data class BottomNavItem(
+    val label: String,
+    val icon: ImageVector,
+    val selectedIcon: ImageVector
+)
+
+private val bottomNavItems = listOf(
+    BottomNavItem("Home", Icons.Default.Home, Icons.Default.Home),
+    BottomNavItem("Search", Icons.Default.Search, Icons.Default.Search),
+    BottomNavItem("Wishlist", Icons.Default.FavoriteBorder, Icons.Default.Favorite),
+    BottomNavItem("Profile", Icons.Default.Menu, Icons.Default.Menu)
+)
+
+// ─── Bottom Navigation — matches Stitch: 4 tabs, active pill ──────────────────
+@Composable
+internal fun CatalogBottomBar(
+    selectedIndex: Int,
+    onItemSelected: (Int) -> Unit
+) {
+    NavigationBar(
+        containerColor = MaterialTheme.colorScheme.surfaceContainerLow,
+        tonalElevation = 0.dp
+    ) {
+        bottomNavItems.forEachIndexed { index, item ->
+            NavigationBarItem(
+                selected = selectedIndex == index,
+                onClick = rememberDebouncedOnClick { onItemSelected(index) },
+                icon = {
+                    Icon(
+                        imageVector = if (selectedIndex == index) {
+                            item.selectedIcon
+                        } else {
+                            item.icon
+                        },
+                        contentDescription = item.label
+                    )
+                },
+                label = {
+                    Text(
+                        text = item.label,
+                        style = MaterialTheme.typography.labelMedium
+                    )
+                },
+                colors = NavigationBarItemDefaults.colors(
+                    // Stitch: primary-container pill for active item
+                    indicatorColor = MaterialTheme.colorScheme.primaryContainer,
+                    selectedIconColor = MaterialTheme.colorScheme.onPrimaryContainer,
+                    selectedTextColor = MaterialTheme.colorScheme.onPrimaryContainer,
+                    unselectedIconColor = MaterialTheme.colorScheme.onSurfaceVariant,
+                    unselectedTextColor = MaterialTheme.colorScheme.onSurfaceVariant
+                )
+            )
+        }
+    }
+}
diff --git a/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Catalogfab.kt b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Catalogfab.kt
new file mode 100644
index 0000000..0aae112
--- /dev/null
+++ b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Catalogfab.kt
@@ -0,0 +1,27 @@
+package com.example.catalogapp.feature.catalog.components
+
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Tune
+import androidx.compose.material3.FloatingActionButton
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.components.rememberDebouncedOnClick
+
+// ─── FAB — matches Stitch: filter tune icon, secondary-container ─────────────
+@Composable
+internal fun CatalogFab(onClick: () -> Unit) {
+    FloatingActionButton(
+        onClick = rememberDebouncedOnClick(onClick),
+        containerColor = MaterialTheme.colorScheme.secondaryContainer,
+        contentColor = MaterialTheme.colorScheme.onSecondaryContainer,
+        shape = RoundedCornerShape(16.dp)
+    ) {
+        Icon(
+            imageVector = Icons.Default.Tune,
+            contentDescription = "Filter"
+        )
+    }
+}
diff --git a/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Catalogtopbar.kt b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Catalogtopbar.kt
new file mode 100644
index 0000000..152a53a
--- /dev/null
+++ b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Catalogtopbar.kt
@@ -0,0 +1,51 @@
+package com.example.catalogapp.feature.catalog.components
+
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Menu
+import androidx.compose.material.icons.filled.Search
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
+import androidx.compose.material3.TopAppBarDefaults
+import androidx.compose.runtime.Composable
+import com.example.catalogapp.core.designsystem.components.rememberDebouncedOnClick
+
+// ─── Top App Bar — matches Stitch: menu icon + title + search ─────────────────
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+internal fun CatalogTopBar(onSearchClick: () -> Unit) {
+    TopAppBar(
+        navigationIcon = {
+            IconButton(rememberDebouncedOnClick { }) {
+                Icon(
+                    imageVector = Icons.Default.Menu,
+                    contentDescription = "Menu",
+                    tint = MaterialTheme.colorScheme.primary
+                )
+            }
+        },
+        title = {
+            Text(
+                text = "CatalogApp",
+                style = MaterialTheme.typography.titleLarge,
+                color = MaterialTheme.colorScheme.primary
+            )
+        },
+        actions = {
+            IconButton(onClick = rememberDebouncedOnClick(onSearchClick)) {
+                Icon(
+                    imageVector = Icons.Default.Search,
+                    contentDescription = "Search",
+                    tint = MaterialTheme.colorScheme.primary
+                )
+            }
+        },
+        // Stitch: surface-container-low background
+        colors = TopAppBarDefaults.topAppBarColors(
+            containerColor = MaterialTheme.colorScheme.surfaceContainerLow
+        )
+    )
+}
diff --git a/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Categorychips.kt b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Categorychips.kt
new file mode 100644
index 0000000..6a3d995
--- /dev/null
+++ b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Categorychips.kt
@@ -0,0 +1,71 @@
+package com.example.catalogapp.feature.catalog.components
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyRow
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.components.rememberDebouncedOnClick
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+
+// ─── Category chips — matches Stitch exactly ─────────────────────────────────
+@Composable
+internal fun CategoryChips(
+    categories: List<String>,
+    selectedCategory: String,
+    onCategorySelected: (String) -> Unit
+) {
+    val spacing = CatalogTheme.spacing
+    LazyRow(
+        contentPadding = PaddingValues(horizontal = spacing.md),
+        horizontalArrangement = Arrangement.spacedBy(spacing.sm),
+        modifier = Modifier.padding(vertical = spacing.sm)
+    ) {
+        items(categories) { category ->
+            CategoryChip(
+                label = category.replaceFirstChar { it.uppercase() },
+                isSelected = category == selectedCategory,
+                onClick = rememberDebouncedOnClick { onCategorySelected(category) }
+            )
+        }
+    }
+}
+
+@Composable
+private fun CategoryChip(
+    label: String,
+    isSelected: Boolean,
+    onClick: () -> Unit
+) {
+    val spacing = CatalogTheme.spacing
+    // Stitch: tertiary-container for active, surface-container-high for inactive
+    val containerColor = if (isSelected) {
+        MaterialTheme.colorScheme.tertiaryContainer
+    } else {
+        MaterialTheme.colorScheme.surfaceContainerHigh
+    }
+    val contentColor = if (isSelected) {
+        MaterialTheme.colorScheme.onTertiaryContainer
+    } else {
+        MaterialTheme.colorScheme.onSurfaceVariant
+    }
+    Surface(
+        onClick = onClick,
+        shape = RoundedCornerShape(12.dp),
+        color = containerColor,
+        contentColor = contentColor
+    ) {
+        Text(
+            text = label,
+            style = MaterialTheme.typography.labelLarge,
+            modifier = Modifier.padding(horizontal = spacing.lg, vertical = spacing.sm)
+        )
+    }
+}
diff --git a/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/ProductGridSkeleton.kt b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/ProductGridSkeleton.kt
new file mode 100644
index 0000000..ed5bf9d
--- /dev/null
+++ b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/ProductGridSkeleton.kt
@@ -0,0 +1,30 @@
+package com.example.catalogapp.feature.catalog.components
+
+import androidx.compose.foundation.layout.Arrangement.spacedBy
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.lazy.grid.GridCells
+import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import com.example.catalogapp.core.designsystem.components.ProductCardSkeleton
+import com.example.catalogapp.core.designsystem.theme.LocalSpacing
+
+private const val SKELETON_ITEM_COUNT = 4
+private const val GRID_COLUMN_COUNT = 2
+
+@Composable
+internal fun ProductGridSkeleton(modifier: Modifier = Modifier) {
+    val spacing = LocalSpacing.current
+    LazyVerticalGrid(
+        columns = GridCells.Fixed(GRID_COLUMN_COUNT),
+        modifier = modifier,
+        contentPadding = PaddingValues(spacing.md),
+        horizontalArrangement = spacedBy(spacing.sm),
+        verticalArrangement = spacedBy(spacing.sm)
+    ) {
+        items(SKELETON_ITEM_COUNT) {
+            ProductCardSkeleton()
+        }
+    }
+}
+
diff --git a/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Productcard.kt b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Productcard.kt
new file mode 100644
index 0000000..cb99d9b
--- /dev/null
+++ b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Productcard.kt
@@ -0,0 +1,191 @@
+package com.example.catalogapp.feature.catalog.components
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.aspectRatio
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.FavoriteBorder
+import androidx.compose.material.icons.filled.Star
+import androidx.compose.material3.Card
+import androidx.compose.material3.CardDefaults
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.shadow
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.components.CatalogAsyncImage
+import com.example.catalogapp.core.designsystem.components.ProductCardDefaults
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+import com.example.catalogapp.core.designsystem.theme.Spacing
+import com.example.catalogapp.domain.product.Product
+import java.util.Locale
+
+private const val REVIEW_COUNT_MULTIPLIER = 100
+
+// ─── Product card — matches Stitch exactly ────────────────────────────────────
+@Composable
+internal fun ProductCard(
+    product: Product,
+    onClick: () -> Unit
+) {
+    val spacing = CatalogTheme.spacing
+    Card(
+        modifier = Modifier
+            .fillMaxWidth()
+            .shadow(
+                elevation = 2.dp,
+                shape = RoundedCornerShape(12.dp),
+                ambientColor = Color.Black.copy(alpha = 0.04f),
+                spotColor = Color.Black.copy(alpha = 0.04f)
+            )
+            .clickable { onClick() },
+        shape = RoundedCornerShape(12.dp),
+        colors = CardDefaults.cardColors(
+            // Stitch: surface-container-lowest for card background
+            containerColor = MaterialTheme.colorScheme.surfaceContainerLowest
+        ),
+        elevation = CardDefaults.cardElevation(defaultElevation = 0.dp)
+    ) {
+        Column {
+            ProductImageSection(product = product, spacing = spacing)
+            ProductInfoSection(product = product, spacing = spacing)
+        }
+    }
+}
+
+// ─── Image with badge and wishlist overlay ────────────────────────────────────
+@Composable
+private fun ProductImageSection(
+    product: Product,
+    spacing: Spacing
+) {
+    Box(
+        modifier = Modifier
+            .fillMaxWidth()
+            .aspectRatio(
+                ProductCardDefaults.IMAGE_ASPECT_WIDTH /
+                        ProductCardDefaults.IMAGE_ASPECT_HEIGHT
+            )
+    ) {
+        CatalogAsyncImage(
+            imageUrl = product.imageUrl,
+            contentDescription = product.title,
+            modifier = Modifier
+                .fillMaxSize()
+                .background(MaterialTheme.colorScheme.surfaceVariant)
+        )
+
+        // Stitch: discount badge top-left, secondary-container color
+        Box(
+            modifier = Modifier
+                .padding(spacing.sm)
+                .align(Alignment.TopStart)
+                .background(
+                    color = MaterialTheme.colorScheme.secondaryContainer,
+                    shape = RoundedCornerShape(8.dp)
+                )
+                .padding(horizontal = spacing.sm, vertical = spacing.xs)
+        ) {
+            Text(
+                text = "15% OFF",
+                style = MaterialTheme.typography.labelMedium,
+                color = MaterialTheme.colorScheme.onSecondaryContainer
+            )
+        }
+
+        // Stitch: wishlist button top-right, semi-transparent white
+        Box(
+            modifier = Modifier
+                .padding(spacing.sm)
+                .align(Alignment.TopEnd)
+                .size(32.dp)
+                .background(
+                    color = MaterialTheme.colorScheme.surface.copy(alpha = 0.8f),
+                    shape = CircleShape
+                ),
+            contentAlignment = Alignment.Center
+        ) {
+            Icon(
+                imageVector = Icons.Default.FavoriteBorder,
+                contentDescription = "Add to wishlist",
+                modifier = Modifier.size(20.dp),
+                tint = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+        }
+    }
+}
+
+// ─── Title, rating, price ──────────────────────────────────────────────────────
+@Composable
+private fun ProductInfoSection(
+    product: Product,
+    spacing: Spacing
+) {
+    Column(
+        modifier = Modifier.padding(spacing.md),
+        verticalArrangement = Arrangement.spacedBy(spacing.xs)
+    ) {
+        // Title — Stitch: body-md, 2 lines max
+        Text(
+            text = product.title,
+            style = MaterialTheme.typography.bodyMedium,
+            maxLines = 2,
+            overflow = TextOverflow.Ellipsis,
+            color = MaterialTheme.colorScheme.onSurface
+        )
+        RatingRow(rating = product.rating)
+        // Price — Stitch: title-lg style, primary color
+        Text(
+            // Explicit Locale.US: avoids ImplicitDefaultLocale and keeps digits
+            // consistent regardless of device locale (comma vs. dot separators).
+            text = "₹${String.format(Locale.US, "%.0f", product.price)}",
+            style = MaterialTheme.typography.titleMedium,
+            color = MaterialTheme.colorScheme.primary
+        )
+    }
+}
+
+// ─── Rating row — matches Stitch: number first, filled star, count ────────────
+@Composable
+private fun RatingRow(rating: Float) {
+    Row(
+        verticalAlignment = Alignment.CenterVertically,
+        horizontalArrangement = Arrangement.spacedBy(2.dp)
+    ) {
+        // Stitch: rating number in secondary color
+        Text(
+            // Explicit Locale.US: avoids ImplicitDefaultLocale.
+            text = String.format(Locale.US, "%.1f", rating),
+            style = MaterialTheme.typography.labelMedium,
+            color = MaterialTheme.colorScheme.secondary
+        )
+        // Stitch: filled star icon in secondary color
+        Icon(
+            imageVector = Icons.Default.Star,
+            contentDescription = null,
+            modifier = Modifier.size(14.dp),
+            tint = MaterialTheme.colorScheme.secondary
+        )
+        // Stitch: review count in outline-variant color
+        Text(
+            text = "(${(rating * REVIEW_COUNT_MULTIPLIER).toInt()})",
+            style = MaterialTheme.typography.labelMedium,
+            color = MaterialTheme.colorScheme.outlineVariant
+        )
+    }
+}
diff --git a/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Productgrid.kt b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Productgrid.kt
new file mode 100644
index 0000000..fb91052
--- /dev/null
+++ b/feature/catalog/src/main/java/com/example/catalogapp/feature/catalog/components/Productgrid.kt
@@ -0,0 +1,39 @@
+package com.example.catalogapp.feature.catalog.components
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.lazy.grid.GridCells
+import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
+import androidx.compose.foundation.lazy.grid.items
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import com.example.catalogapp.core.designsystem.components.rememberDebouncedOnClick
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+import com.example.catalogapp.domain.product.Product
+
+// ─── Product grid ─────────────────────────────────────────────────────────────
+@Composable
+internal fun ProductGrid(
+    products: List<Product>,
+    onProductClick: (Int) -> Unit
+) {
+    val spacing = CatalogTheme.spacing
+    LazyVerticalGrid(
+        columns = GridCells.Fixed(2),
+        contentPadding = PaddingValues(spacing.md),
+        horizontalArrangement = Arrangement.spacedBy(spacing.md),
+        verticalArrangement = Arrangement.spacedBy(spacing.md),
+        modifier = Modifier.fillMaxSize()
+    ) {
+        items(
+            items = products,
+            key = { product -> product.id }
+        ) { product ->
+            ProductCard(
+                product = product,
+                onClick = rememberDebouncedOnClick { onProductClick(product.id) }
+            )
+        }
+    }
+}
diff --git a/feature/catalog/src/test/java/com/example/catalogapp/feature/catalog/CatalogViewModelTest.kt b/feature/catalog/src/test/java/com/example/catalogapp/feature/catalog/CatalogViewModelTest.kt
new file mode 100644
index 0000000..4b782a4
--- /dev/null
+++ b/feature/catalog/src/test/java/com/example/catalogapp/feature/catalog/CatalogViewModelTest.kt
@@ -0,0 +1,206 @@
+package com.example.catalogapp.feature.catalog
+
+import com.example.catalogapp.domain.product.GetProductsUseCase
+import com.example.catalogapp.domain.product.Product
+import io.mockk.every
+import io.mockk.mockk
+import io.mockk.verify
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.flowOf
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.test.StandardTestDispatcher
+import kotlinx.coroutines.test.advanceUntilIdle
+import kotlinx.coroutines.test.resetMain
+import kotlinx.coroutines.test.runTest
+import kotlinx.coroutines.test.setMain
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Before
+import org.junit.Test
+
+@OptIn(ExperimentalCoroutinesApi::class)
+class CatalogViewModelTest {
+
+    private val testDispatcher = StandardTestDispatcher()
+    private val getProductsUseCase: GetProductsUseCase = mockk()
+    private lateinit var viewModel: CatalogViewModel
+
+    private val fakeProducts = listOf(
+        Product(1, "Backpack", 109.95, "Great bag", "men's clothing", "", 3.9f),
+        Product(2, "Gold Ring", 4500.0, "22K gold", "jewelery", "", 4.5f)
+    )
+
+    @Before
+    fun setUp() {
+        Dispatchers.setMain(testDispatcher)
+    }
+
+    @After
+    fun tearDown() {
+        Dispatchers.resetMain()
+    }
+
+    @Test
+    fun `initial state before loading has empty products and no error`() = runTest {
+        every { getProductsUseCase() } returns flowOf(fakeProducts)
+        viewModel = CatalogViewModel(getProductsUseCase)
+
+        // Don't advance — check the default state before any coroutine runs
+        val initialState = viewModel.uiState.value
+        assertNull(initialState.error)
+        // Either loading or empty initially — both are valid before coroutines run
+        assertFalse(initialState.showError)
+        assertFalse(initialState.showProducts)
+    }
+
+    @Test
+    fun `LoadProducts intent loads products successfully`() = runTest {
+        every { getProductsUseCase() } returns flowOf(fakeProducts)
+        viewModel = CatalogViewModel(getProductsUseCase)
+
+        advanceUntilIdle()
+
+        val state = viewModel.uiState.value
+        assertFalse(state.isLoading)
+        assertNull(state.error)
+        assertEquals(2, state.products.size)
+        assertTrue(state.showProducts)
+        assertFalse(state.showLoading)
+        assertFalse(state.showError)
+        assertFalse(state.showEmpty)
+    }
+
+    @Test
+    fun `SelectCategory intent filters products correctly`() = runTest {
+        every { getProductsUseCase() } returns flowOf(fakeProducts)
+        viewModel = CatalogViewModel(getProductsUseCase)
+        advanceUntilIdle()
+
+        viewModel.processIntent(CatalogIntent.SelectCategory("jewelery"))
+        advanceUntilIdle()
+
+        val state = viewModel.uiState.value
+        assertEquals("jewelery", state.selectedCategory)
+        assertEquals(1, state.filteredProducts.size)
+        assertEquals("Gold Ring", state.filteredProducts[0].title)
+    }
+
+    @Test
+    fun `SelectCategory All shows all products`() = runTest {
+        every { getProductsUseCase() } returns flowOf(fakeProducts)
+        viewModel = CatalogViewModel(getProductsUseCase)
+        advanceUntilIdle()
+
+        viewModel.processIntent(CatalogIntent.SelectCategory("jewelery"))
+        viewModel.processIntent(CatalogIntent.SelectCategory("All"))
+        advanceUntilIdle()
+
+        assertEquals(2, viewModel.uiState.value.filteredProducts.size)
+    }
+
+    @Test
+    fun `error from use case updates state correctly`() = runTest {
+        every { getProductsUseCase() } returns kotlinx.coroutines.flow.flow {
+            throw RuntimeException("Network error")
+        }
+        viewModel = CatalogViewModel(getProductsUseCase)
+        advanceUntilIdle()
+
+        val state = viewModel.uiState.value
+        assertFalse(state.isLoading)
+        assertTrue(state.showError)
+        assertEquals("Network error", state.error)
+        assertTrue(state.products.isEmpty())
+    }
+
+    @Test
+    fun `categories derived from products include All plus unique categories`() = runTest {
+        every { getProductsUseCase() } returns flowOf(fakeProducts)
+        viewModel = CatalogViewModel(getProductsUseCase)
+        advanceUntilIdle()
+
+        val categories = viewModel.uiState.value.categories
+        assertTrue(categories.contains("All"))
+        assertTrue(categories.contains("men's clothing"))
+        assertTrue(categories.contains("jewelery"))
+        assertEquals(3, categories.size)
+    }
+
+    @Test
+    fun `ProductClicked intent sends NavigateToDetail effect`() = runTest {
+        every { getProductsUseCase() } returns flowOf(fakeProducts)
+        viewModel = CatalogViewModel(getProductsUseCase)
+        advanceUntilIdle()
+
+        // Collect effect before sending intent
+        var receivedEffect: CatalogEffect? = null
+        val job = launch {
+            viewModel.effect.collect { receivedEffect = it }
+        }
+
+        viewModel.processIntent(CatalogIntent.ProductClicked(productId = 1))
+        advanceUntilIdle()
+        job.cancel()
+
+        assertTrue(receivedEffect is CatalogEffect.NavigateToDetail)
+        assertEquals(1, (receivedEffect as CatalogEffect.NavigateToDetail).productId)
+    }
+
+    @Test
+    fun `RefreshProducts intent re-fetches products via use case`() = runTest {
+        every { getProductsUseCase() } returns flowOf(fakeProducts)
+        viewModel = CatalogViewModel(getProductsUseCase)
+        advanceUntilIdle()
+
+        viewModel.processIntent(CatalogIntent.RefreshProducts)
+        advanceUntilIdle()
+
+        val state = viewModel.uiState.value
+        assertFalse(state.isRefreshing)
+        assertEquals(2, state.products.size)
+        // getProductsUseCase() should fire once on init, once on refresh —
+        // this is what actually distinguishes a real refresh from the old no-op
+        verify(exactly = 2) { getProductsUseCase() }
+    }
+
+    @Test
+    fun `RefreshProducts intent surfaces error without wiping existing products`() = runTest {
+        every { getProductsUseCase() } returns flowOf(fakeProducts)
+        viewModel = CatalogViewModel(getProductsUseCase)
+        advanceUntilIdle()
+
+        every { getProductsUseCase() } returns kotlinx.coroutines.flow.flow {
+            throw RuntimeException("Refresh failed")
+        }
+        viewModel.processIntent(CatalogIntent.RefreshProducts)
+        advanceUntilIdle()
+
+        val state = viewModel.uiState.value
+        assertFalse(state.isRefreshing)
+        assertEquals("Refresh failed", state.error)
+        // Products from the successful initial load must survive a failed refresh
+        assertEquals(2, state.products.size)
+    }
+    @Test
+    fun `SearchClicked intent sends NavigateToSearch effect`() = runTest {
+        every { getProductsUseCase() } returns flowOf(fakeProducts)
+        viewModel = CatalogViewModel(getProductsUseCase)
+        advanceUntilIdle()
+
+        viewModel.processIntent(CatalogIntent.SearchClicked)
+        advanceUntilIdle()
+
+        var receivedEffect: CatalogEffect? = null
+        val job = launch {
+            viewModel.effect.collect { receivedEffect = it }
+        }
+        advanceUntilIdle()
+        job.cancel()
+
+        assertTrue(receivedEffect is CatalogEffect.NavigateToSearch)
+    }
+}
diff --git a/feature/catalog/src/test/java/com/example/catalogapp/feature/catalog/ExampleUnitTest.kt b/feature/catalog/src/test/java/com/example/catalogapp/feature/catalog/ExampleUnitTest.kt
new file mode 100644
index 0000000..cf88897
--- /dev/null
+++ b/feature/catalog/src/test/java/com/example/catalogapp/feature/catalog/ExampleUnitTest.kt
@@ -0,0 +1,17 @@
+package com.example.catalogapp.feature.catalog
+
+import org.junit.Test
+
+import org.junit.Assert.*
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+class ExampleUnitTest {
+    @Test
+    fun addition_isCorrect() {
+        assertEquals(4, 2 + 2)
+    }
+}
diff --git a/feature/detail/.gitignore b/feature/detail/.gitignore
new file mode 100644
index 0000000..42afabf
--- /dev/null
+++ b/feature/detail/.gitignore
@@ -0,0 +1 @@
+/build
\ No newline at end of file
diff --git a/feature/detail/build.gradle.kts b/feature/detail/build.gradle.kts
new file mode 100644
index 0000000..a95cf8b
--- /dev/null
+++ b/feature/detail/build.gradle.kts
@@ -0,0 +1,62 @@
+plugins {
+    alias(libs.plugins.android.library)
+    alias(libs.plugins.kotlin.compose)
+    alias(libs.plugins.hilt)
+    alias(libs.plugins.ksp)
+    alias(libs.plugins.detekt)
+    jacoco
+}
+
+android {
+    namespace = "com.example.catalogapp.feature.detail"
+    compileSdk = 36
+
+    defaultConfig {
+        minSdk = 24
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    buildFeatures {
+        compose = true
+        buildConfig = true
+    }
+}
+
+jacoco {
+    toolVersion = "0.8.12"
+}
+
+detekt {
+    config.setFrom(files("$rootDir/config/detekt/detekt.yml"))
+    buildUponDefaultConfig = true
+    source.setFrom("src/main/java")
+}
+
+dependencies {
+    implementation(project(":domain:product"))
+    implementation(project(":core:common"))
+    implementation(project(":core:designsystem"))
+
+    implementation(platform(libs.androidx.compose.bom))
+    implementation(libs.androidx.compose.ui)
+    implementation(libs.androidx.compose.material3)
+    implementation(libs.androidx.compose.ui.tooling.preview)
+    implementation(libs.androidx.compose.foundation)
+    implementation(libs.androidx.compose.material.icons.extended)
+    debugImplementation(libs.androidx.compose.ui.tooling)
+
+    implementation(libs.androidx.lifecycle.runtime.ktx)
+    implementation(libs.hilt.android)
+    ksp(libs.hilt.compiler)
+    implementation(libs.hilt.navigation.compose)
+    implementation(libs.kotlinx.coroutines.android)
+    implementation(libs.coil.compose)
+
+    testImplementation(libs.junit)
+    testImplementation(libs.mockk)
+    testImplementation(libs.kotlinx.coroutines.test)
+}
diff --git a/feature/detail/consumer-rules.pro b/feature/detail/consumer-rules.pro
new file mode 100644
index 0000000..e69de29
diff --git a/feature/detail/proguard-rules.pro b/feature/detail/proguard-rules.pro
new file mode 100644
index 0000000..481bb43
--- /dev/null
+++ b/feature/detail/proguard-rules.pro
@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile
\ No newline at end of file
diff --git a/feature/detail/src/androidTest/java/com/example/catalogapp/feature/detail/ExampleInstrumentedTest.kt b/feature/detail/src/androidTest/java/com/example/catalogapp/feature/detail/ExampleInstrumentedTest.kt
new file mode 100644
index 0000000..85960a8
--- /dev/null
+++ b/feature/detail/src/androidTest/java/com/example/catalogapp/feature/detail/ExampleInstrumentedTest.kt
@@ -0,0 +1,24 @@
+package com.example.catalogapp.feature.detail
+
+import androidx.test.platform.app.InstrumentationRegistry
+import androidx.test.ext.junit.runners.AndroidJUnit4
+
+import org.junit.Test
+import org.junit.runner.RunWith
+
+import org.junit.Assert.*
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+@RunWith(AndroidJUnit4::class)
+class ExampleInstrumentedTest {
+    @Test
+    fun useAppContext() {
+        // Context of the app under test.
+        val appContext = InstrumentationRegistry.getInstrumentation().targetContext
+        assertEquals("com.example.catalogapp.feature.detail.test", appContext.packageName)
+    }
+}
diff --git a/feature/detail/src/main/AndroidManifest.xml b/feature/detail/src/main/AndroidManifest.xml
new file mode 100644
index 0000000..8bdb7e1
--- /dev/null
+++ b/feature/detail/src/main/AndroidManifest.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+</manifest>
diff --git a/feature/detail/src/main/java/com/example/catalogapp/feature/detail/DetailContract.kt b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/DetailContract.kt
new file mode 100644
index 0000000..6491562
--- /dev/null
+++ b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/DetailContract.kt
@@ -0,0 +1,34 @@
+package com.example.catalogapp.feature.detail
+
+import com.example.catalogapp.domain.product.Product
+
+// ─── UI State ─────────────────────────────────────────────────────────────────
+data class DetailUiState(
+    val product: Product? = null,
+    val isLoading: Boolean = false,
+    val error: String? = null,
+    val isWishlisted: Boolean = false,
+    val isDescriptionExpanded: Boolean = false
+) {
+    val showLoading: Boolean get() = isLoading && product == null
+    val showError: Boolean get() = error != null && !isLoading && product == null
+    val showContent: Boolean get() = product != null
+}
+
+// ─── Intent ───────────────────────────────────────────────────────────────────
+sealed class DetailIntent {
+    data class LoadProduct(val productId: Int) : DetailIntent()
+    object RetryLoad : DetailIntent()
+    object NavigateBack : DetailIntent()
+    object ToggleWishlist : DetailIntent()
+    object AddToCart : DetailIntent()
+    object ToggleDescription : DetailIntent()
+    object ShareProduct : DetailIntent()
+}
+
+// ─── Effect ───────────────────────────────────────────────────────────────────
+sealed class DetailEffect {
+    object NavigateBack : DetailEffect()
+    data class ShowSnackbar(val message: String) : DetailEffect()
+    data class ShareProduct(val title: String, val price: Double) : DetailEffect()
+}
diff --git a/feature/detail/src/main/java/com/example/catalogapp/feature/detail/DetailScreen.kt b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/DetailScreen.kt
new file mode 100644
index 0000000..d5f501f
--- /dev/null
+++ b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/DetailScreen.kt
@@ -0,0 +1,155 @@
+package com.example.catalogapp.feature.detail
+
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarHostState
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.example.catalogapp.core.designsystem.components.CatalogErrorState
+import com.example.catalogapp.core.designsystem.components.DetailSkeleton
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+import com.example.catalogapp.domain.product.Product
+import com.example.catalogapp.feature.detail.components.DetailBody
+import com.example.catalogapp.feature.detail.components.DetailBottomBar
+import com.example.catalogapp.feature.detail.components.DetailTopBar
+
+@Composable
+fun DetailScreen(
+    productId: Int,
+    onNavigateBack: () -> Unit,
+    viewModel: DetailViewModel = hiltViewModel()
+) {
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    val snackbarHostState = remember { SnackbarHostState() }
+
+    LaunchedEffect(productId) {
+        viewModel.processIntent(DetailIntent.LoadProduct(productId))
+    }
+
+    LaunchedEffect(Unit) {
+        viewModel.effect.collect { effect ->
+            when (effect) {
+                is DetailEffect.NavigateBack -> onNavigateBack()
+                is DetailEffect.ShowSnackbar ->
+                    snackbarHostState.showSnackbar(effect.message)
+
+                is DetailEffect.ShareProduct -> {}
+            }
+        }
+    }
+
+    DetailContent(
+        uiState = uiState,
+        snackbarHostState = snackbarHostState,
+        onIntent = viewModel::processIntent
+    )
+}
+
+@Composable
+internal fun DetailContent(
+    uiState: DetailUiState,
+    snackbarHostState: SnackbarHostState = remember { SnackbarHostState() },
+    onIntent: (DetailIntent) -> Unit
+) {
+    val scrollState = rememberScrollState()
+
+    Scaffold(
+        snackbarHost = { SnackbarHost(snackbarHostState) },
+        bottomBar = {
+            if (uiState.showContent) {
+                DetailBottomBar(
+                    isWishlisted = uiState.isWishlisted,
+                    onWishlistClick = { onIntent(DetailIntent.ToggleWishlist) },
+                    onAddToCartClick = { onIntent(DetailIntent.AddToCart) }
+                )
+            }
+        }
+    ) { paddingValues ->
+        Box(modifier = Modifier.fillMaxSize()) {
+            when {
+                uiState.showLoading -> DetailSkeleton(
+                    modifier = Modifier
+                        .fillMaxSize()
+                        .padding(bottom = paddingValues.calculateBottomPadding())
+                )
+                uiState.showError -> CatalogErrorState(
+                    message = uiState.error ?: "Unknown error",
+                    onRetry = { onIntent(DetailIntent.RetryLoad) }
+                )
+
+                uiState.showContent -> {
+                    val product = uiState.product!!
+                    DetailBody(
+                        product = product,
+                        uiState = uiState,
+                        onIntent = onIntent,
+                        modifier = Modifier
+                            .fillMaxSize()
+                            .padding(bottom = paddingValues.calculateBottomPadding())
+                            .verticalScroll(scrollState)
+                    )
+                }
+            }
+            // Top bar always on top regardless of content state
+            DetailTopBar(
+                onBackClick = { onIntent(DetailIntent.NavigateBack) },
+                onShareClick = { onIntent(DetailIntent.ShareProduct) }
+            )
+        }
+    }
+}
+
+@Preview(showBackground = true, name = "Detail - Content")
+@Composable
+internal fun DetailContentPreview() {
+    CatalogTheme {
+        DetailContent(
+            uiState = DetailUiState(product = previewProduct),
+            onIntent = {}
+        )
+    }
+}
+
+@Preview(showBackground = true, name = "Detail - Loading")
+@Composable
+internal fun DetailLoadingPreview() {
+    CatalogTheme {
+        DetailContent(
+            uiState = DetailUiState(isLoading = true),
+            onIntent = {}
+        )
+    }
+}
+
+@Preview(showBackground = true, name = "Detail - Error")
+@Composable
+internal fun DetailErrorPreview() {
+    CatalogTheme {
+        DetailContent(
+            uiState = DetailUiState(error = "Product not found"),
+            onIntent = {}
+        )
+    }
+}
+
+internal val previewProduct = Product(
+    id = 1,
+    title = "Titan Celestial Smartwatch - Midnight Edition",
+    price = 12999.0,
+    description = "Experience precision and luxury with the Celestial Midnight Edition. Features a brilliant 1.43\"" +
+            " AMOLED display with 1000 nits brightness.",
+    category = "electronics",
+    imageUrl = "",
+    rating = 4.8f
+)
diff --git a/feature/detail/src/main/java/com/example/catalogapp/feature/detail/DetailViewModel.kt b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/DetailViewModel.kt
new file mode 100644
index 0000000..0a8cdee
--- /dev/null
+++ b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/DetailViewModel.kt
@@ -0,0 +1,92 @@
+package com.example.catalogapp.feature.detail
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.example.catalogapp.domain.product.ProductRepository
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.receiveAsFlow
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+@HiltViewModel
+class DetailViewModel @Inject constructor(
+    private val productRepository: ProductRepository
+) : ViewModel() {
+
+    private val _uiState = MutableStateFlow(DetailUiState())
+    val uiState: StateFlow<DetailUiState> = _uiState.asStateFlow()
+
+    private val _effect = Channel<DetailEffect>(Channel.BUFFERED)
+    val effect = _effect.receiveAsFlow()
+    private var currentProductId: Int? = null
+
+    fun processIntent(intent: DetailIntent) {
+        when (intent) {
+            is DetailIntent.LoadProduct -> loadProduct(intent.productId)
+            is DetailIntent.RetryLoad -> currentProductId?.let { loadProduct(it) }
+            is DetailIntent.NavigateBack -> navigateBack()
+            is DetailIntent.ToggleWishlist -> toggleWishlist()
+            is DetailIntent.AddToCart -> addToCart()
+            is DetailIntent.ToggleDescription -> toggleDescription()
+            is DetailIntent.ShareProduct -> shareProduct()
+        }
+    }
+
+    private fun loadProduct(productId: Int) {
+        currentProductId = productId
+        viewModelScope.launch {
+            _uiState.update { it.copy(isLoading = true, error = null) }
+            val product = productRepository.getProductById(productId)
+            if (product != null) {
+                _uiState.update { it.copy(isLoading = false, product = product) }
+            } else {
+                _uiState.update {
+                    it.copy(
+                        isLoading = false,
+                        error = "Product not found"
+                    )
+                }
+            }
+        }
+    }
+
+    private fun navigateBack() {
+        viewModelScope.launch {
+            _effect.send(DetailEffect.NavigateBack)
+        }
+    }
+
+    private fun toggleWishlist() {
+        _uiState.update { it.copy(isWishlisted = !it.isWishlisted) }
+        viewModelScope.launch {
+            val message = if (_uiState.value.isWishlisted) {
+                "Added to wishlist"
+            } else {
+                "Removed from wishlist"
+            }
+            _effect.send(DetailEffect.ShowSnackbar(message))
+        }
+    }
+
+    private fun addToCart() {
+        viewModelScope.launch {
+            _effect.send(DetailEffect.ShowSnackbar("Added to cart"))
+        }
+    }
+
+    private fun toggleDescription() {
+        _uiState.update { it.copy(isDescriptionExpanded = !it.isDescriptionExpanded) }
+    }
+
+    private fun shareProduct() {
+        val product = _uiState.value.product ?: return
+        viewModelScope.launch {
+            _effect.send(DetailEffect.ShareProduct(product.title, product.price))
+        }
+    }
+}
diff --git a/feature/detail/src/main/java/com/example/catalogapp/feature/detail/ProductFeatureProvider.kt b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/ProductFeatureProvider.kt
new file mode 100644
index 0000000..bfee12b
--- /dev/null
+++ b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/ProductFeatureProvider.kt
@@ -0,0 +1,71 @@
+package com.example.catalogapp.feature.detail
+
+private const val FIRST_N_CHARACTERS_FROM_STRING = 8
+
+data class ProductFeature(val icon: String, val label: String, val value: String)
+
+object ProductFeatureProvider {
+
+    fun getFeaturesForProduct(
+        category: String, rating: Float
+    ): List<ProductFeature> {
+        val ratingFormatted = String.format(java.util.Locale.getDefault(), "%.1f", rating)
+
+        return when {
+            category.contains("electronic", ignoreCase = true) || category.contains(
+                "phone",
+                ignoreCase = true
+            ) || category.contains("laptop", ignoreCase = true) -> listOf(
+                ProductFeature("◆", "Build", "Premium"),
+                ProductFeature("⚡", "Battery", "Long Life"),
+                ProductFeature("★", "Rating", ratingFormatted),
+                ProductFeature("✓", "Warranty", "1 Year")
+            )
+
+            category.contains("jewelery", ignoreCase = true) || category.contains(
+                "jewellery",
+                ignoreCase = true
+            ) || category.contains("jewelry", ignoreCase = true) -> listOf(
+                ProductFeature("◆", "Material", "Certified"),
+                ProductFeature("✦", "Purity", "Hallmark"),
+                ProductFeature("★", "Rating", ratingFormatted),
+                ProductFeature("✓", "Finish", "Polished")
+            )
+
+            category.contains("clothing", ignoreCase = true) || category.contains(
+                "fashion",
+                ignoreCase = true
+            ) || category.contains("wear", ignoreCase = true) -> listOf(
+                ProductFeature("◆", "Fabric", "Premium"),
+                ProductFeature("✦", "Fit", "Regular"),
+                ProductFeature("★", "Rating", ratingFormatted),
+                ProductFeature("✓", "Care", "Easy Wash")
+            )
+
+            category.contains("men", ignoreCase = true) -> listOf(
+                ProductFeature("◆", "Style", "Modern"),
+                ProductFeature("✦", "Fit", "Slim Fit"),
+                ProductFeature("★", "Rating", ratingFormatted),
+                ProductFeature("✓", "Care", "Easy Wash")
+            )
+
+            category.contains("women", ignoreCase = true) -> listOf(
+                ProductFeature("◆", "Style", "Trendy"),
+                ProductFeature("✦", "Fit", "Comfort"),
+                ProductFeature("★", "Rating", ratingFormatted),
+                ProductFeature("✓", "Care", "Easy Wash")
+            )
+
+            else -> listOf(
+                ProductFeature("◆", "Quality", "Premium"),
+                ProductFeature(
+                    "✦",
+                    "Type",
+                    category.take(FIRST_N_CHARACTERS_FROM_STRING)
+                        .replaceFirstChar { it.uppercase() }),
+                ProductFeature("★", "Rating", ratingFormatted),
+                ProductFeature("✓", "Delivery", "Fast")
+            )
+        }
+    }
+}
diff --git a/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailBody.kt b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailBody.kt
new file mode 100644
index 0000000..3a69e86
--- /dev/null
+++ b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailBody.kt
@@ -0,0 +1,48 @@
+package com.example.catalogapp.feature.detail.components
+
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.padding
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+import com.example.catalogapp.domain.product.Product
+import com.example.catalogapp.feature.detail.DetailIntent
+import com.example.catalogapp.feature.detail.DetailUiState
+
+@Composable
+internal fun DetailBody(
+    product: Product,
+    uiState: DetailUiState,
+    onIntent: (DetailIntent) -> Unit,
+    modifier: Modifier = Modifier
+) {
+    val spacing = CatalogTheme.spacing
+    androidx.compose.foundation.layout.Column(modifier = modifier) {
+        // Hero image — full bleed, 4:5 aspect ratio
+        DetailHeroImage(
+            imageUrl = product.imageUrl,
+            title = product.title
+        )
+        // Content card overlapping hero by -mt-12 (48dp)
+        Box(
+            modifier = Modifier.padding(horizontal = spacing.md)
+        ) {
+            DetailContentCard(
+                product = product,
+                isDescriptionExpanded = uiState.isDescriptionExpanded,
+                onToggleDescription = { onIntent(DetailIntent.ToggleDescription) }
+            )
+        }
+        // Reviews section — OUTSIDE the white card, in surface background
+        Box(
+            modifier = Modifier.padding(
+                top = spacing.md,
+                start = spacing.md,
+                end = spacing.md,
+                bottom = spacing.xl
+            )
+        ) {
+            DetailReviewsSection()
+        }
+    }
+}
diff --git a/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailBottomBar.kt b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailBottomBar.kt
new file mode 100644
index 0000000..65d8572
--- /dev/null
+++ b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailBottomBar.kt
@@ -0,0 +1,128 @@
+package com.example.catalogapp.feature.detail.components
+
+import androidx.compose.foundation.BorderStroke
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.navigationBarsPadding
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Favorite
+import androidx.compose.material.icons.filled.FavoriteBorder
+import androidx.compose.material.icons.filled.ShoppingBag
+import androidx.compose.material3.Button
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedButton
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.components.rememberDebouncedOnClick
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+
+private const val BOTTOM_BAR_HEIGHT = 96
+private const val WISHLIST_BUTTON_SIZE = 56
+private const val WISHLIST_CORNER = 24
+private const val CART_BUTTON_HEIGHT = 56
+private const val CART_BUTTON_CORNER = 24
+private const val CART_ICON_SIZE = 24
+
+@Composable
+internal fun DetailBottomBar(
+    isWishlisted: Boolean,
+    onWishlistClick: () -> Unit,
+    onAddToCartClick: () -> Unit,
+    modifier: Modifier = Modifier
+) {
+    val spacing = CatalogTheme.spacing
+    Surface(
+        modifier = modifier
+            .fillMaxWidth()
+            .navigationBarsPadding(),
+        color = MaterialTheme.colorScheme.surface.copy(alpha = 0.9f),
+        tonalElevation = 0.dp,
+        shadowElevation = 0.dp
+    ) {
+        Row(
+            modifier = Modifier
+                .fillMaxWidth()
+                .height(BOTTOM_BAR_HEIGHT.dp)
+                .padding(horizontal = spacing.md, vertical = spacing.md),
+            horizontalArrangement = Arrangement.spacedBy(spacing.md),
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            WishlistButton(isWishlisted = isWishlisted, onClick = onWishlistClick)
+            AddToCartButton(onClick = onAddToCartClick, modifier = Modifier.weight(1f))
+        }
+    }
+}
+
+@Composable
+private fun WishlistButton(isWishlisted: Boolean, onClick: () -> Unit) {
+    OutlinedButton(
+        onClick = rememberDebouncedOnClick(onClick),
+        modifier = Modifier.size(WISHLIST_BUTTON_SIZE.dp),
+        shape = RoundedCornerShape(WISHLIST_CORNER.dp),
+        border = BorderStroke(2.dp, MaterialTheme.colorScheme.primary),
+        colors = ButtonDefaults.outlinedButtonColors(
+            contentColor = MaterialTheme.colorScheme.primary
+        ),
+        contentPadding = PaddingValues(0.dp)
+    ) {
+        Icon(
+            imageVector = if (isWishlisted) Icons.Default.Favorite else Icons.Default.FavoriteBorder,
+            contentDescription = if (isWishlisted) "Remove from wishlist" else "Add to wishlist",
+            tint = MaterialTheme.colorScheme.primary
+        )
+    }
+}
+
+@Composable
+private fun AddToCartButton(onClick: () -> Unit, modifier: Modifier = Modifier) {
+    val spacing = CatalogTheme.spacing
+    Button(
+        onClick = rememberDebouncedOnClick(onClick),
+        modifier = modifier.height(CART_BUTTON_HEIGHT.dp),
+        shape = RoundedCornerShape(CART_BUTTON_CORNER.dp),
+        colors = ButtonDefaults.buttonColors(
+            containerColor = MaterialTheme.colorScheme.secondaryContainer,
+            contentColor = MaterialTheme.colorScheme.onSecondaryContainer
+        )
+    ) {
+        Icon(
+            imageVector = Icons.Default.ShoppingBag,
+            contentDescription = null,
+            modifier = Modifier.size(CART_ICON_SIZE.dp)
+        )
+        Spacer(modifier = Modifier.width(spacing.sm))
+        Text(
+            text = "Add to Cart",
+            style = MaterialTheme.typography.titleMedium,
+            fontWeight = FontWeight.SemiBold
+        )
+    }
+}
+
+@Preview(showBackground = true)
+@Composable
+internal fun DetailBottomBarPreview() {
+    CatalogTheme {
+        DetailBottomBar(
+            isWishlisted = false,
+            onWishlistClick = {},
+            onAddToCartClick = {}
+        )
+    }
+}
diff --git a/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailContentCard.kt b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailContentCard.kt
new file mode 100644
index 0000000..56381be
--- /dev/null
+++ b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailContentCard.kt
@@ -0,0 +1,72 @@
+package com.example.catalogapp.feature.detail.components
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.offset
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.Card
+import androidx.compose.material3.CardDefaults
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+import com.example.catalogapp.domain.product.Product
+import com.example.catalogapp.feature.detail.previewProduct
+
+private const val CARD_CORNER = 24
+private const val CARD_OVERLAP_DP = 28
+
+@Composable
+internal fun DetailContentCard(
+    product: Product,
+    isDescriptionExpanded: Boolean,
+    onToggleDescription: () -> Unit,
+    modifier: Modifier = Modifier
+) {
+    val spacing = CatalogTheme.spacing
+    // Stitch: -mt-12 (28dp negative offset), rounded-3xl, surface-container-lowest, p-lg
+    Card(
+        modifier = modifier
+            .fillMaxWidth()
+            .offset(y = (-CARD_OVERLAP_DP).dp),
+        shape = RoundedCornerShape(CARD_CORNER.dp),
+        colors = CardDefaults.cardColors(
+            containerColor = MaterialTheme.colorScheme.surfaceContainerLowest
+        ),
+        elevation = CardDefaults.cardElevation(defaultElevation = 2.dp)
+    ) {
+        Column(modifier = Modifier.fillMaxWidth()) {
+            // Product header: brand, title, rating, availability
+            DetailProductHeader(product = product)
+            // Price row
+            DetailPriceSection(price = product.price)
+            Spacer(modifier = Modifier.height(spacing.lg))
+            // Features bento 2-column grid
+            DetailFeaturesGrid(product = product)
+            Spacer(modifier = Modifier.height(spacing.xl))
+            // Collapsible description
+            DetailDescriptionSection(
+                description = product.description,
+                isExpanded = isDescriptionExpanded,
+                onToggle = onToggleDescription
+            )
+            Spacer(modifier = Modifier.height(spacing.md))
+        }
+    }
+}
+
+@Preview(showBackground = true)
+@Composable
+internal fun DetailContentCardPreview() {
+    CatalogTheme {
+        DetailContentCard(
+            product = previewProduct,
+            isDescriptionExpanded = false,
+            onToggleDescription = {}
+        )
+    }
+}
diff --git a/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailDescriptionSection.kt b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailDescriptionSection.kt
new file mode 100644
index 0000000..4fc05f1
--- /dev/null
+++ b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailDescriptionSection.kt
@@ -0,0 +1,69 @@
+package com.example.catalogapp.feature.detail.components
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.tooling.preview.Preview
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+import com.example.catalogapp.feature.detail.previewProduct
+
+private const val COLLAPSED_MAX_LINES = 3
+
+@Composable
+internal fun DetailDescriptionSection(
+    description: String,
+    isExpanded: Boolean,
+    onToggle: () -> Unit,
+    modifier: Modifier = Modifier
+) {
+    val spacing = CatalogTheme.spacing
+    Column(
+        modifier = modifier
+            .fillMaxWidth()
+            .padding(horizontal = spacing.lg)
+    ) {
+        // Stitch: font-title-lg text-title-lg
+        Text(
+            text = "Description",
+            style = MaterialTheme.typography.titleLarge,
+            color = MaterialTheme.colorScheme.onSurface
+        )
+        Spacer(modifier = Modifier.height(spacing.sm))
+        // Stitch: text-on-surface-variant font-body-lg line-clamp-3 when collapsed
+        Text(
+            text = description,
+            style = MaterialTheme.typography.bodyLarge,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            maxLines = if (isExpanded) Int.MAX_VALUE else COLLAPSED_MAX_LINES,
+            overflow = if (isExpanded) TextOverflow.Visible else TextOverflow.Ellipsis
+        )
+        // Stitch: text-primary font-label-lg "Read More / Read Less"
+        TextButton(onClick = onToggle) {
+            Text(
+                text = if (isExpanded) "Read Less" else "Read More",
+                style = MaterialTheme.typography.labelLarge,
+                color = MaterialTheme.colorScheme.primary
+            )
+        }
+    }
+}
+
+@Preview(showBackground = true)
+@Composable
+internal fun DetailDescriptionPreview() {
+    CatalogTheme {
+        DetailDescriptionSection(
+            description = previewProduct.description,
+            isExpanded = false,
+            onToggle = {}
+        )
+    }
+}
diff --git a/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailFeaturesGrid.kt b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailFeaturesGrid.kt
new file mode 100644
index 0000000..126f581
--- /dev/null
+++ b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailFeaturesGrid.kt
@@ -0,0 +1,120 @@
+package com.example.catalogapp.feature.detail.components
+
+import androidx.compose.foundation.border
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+import com.example.catalogapp.domain.product.Product
+import com.example.catalogapp.feature.detail.ProductFeature
+import com.example.catalogapp.feature.detail.ProductFeatureProvider
+import com.example.catalogapp.feature.detail.previewProduct
+
+private const val FEATURE_TILE_CORNER = 16
+
+@Composable
+internal fun DetailFeaturesGrid(
+    product: Product,
+    modifier: Modifier = Modifier
+) {
+    val spacing = CatalogTheme.spacing
+    val features = ProductFeatureProvider.getFeaturesForProduct(
+        category = product.category,
+        rating = product.rating
+    )
+
+    // Fixed 2x2 grid using two Rows — no LazyVerticalGrid needed for 4 static items
+    // LazyVerticalGrid inside verticalScroll causes unbounded height conflict
+    Column(
+        modifier = modifier
+            .fillMaxWidth()
+            .padding(horizontal = spacing.lg),
+        verticalArrangement = Arrangement.spacedBy(spacing.sm)
+    ) {
+        Row(
+            modifier = Modifier.fillMaxWidth(),
+            horizontalArrangement = Arrangement.spacedBy(spacing.sm)
+        ) {
+            FeatureTile(
+                feature = features[0],
+                modifier = Modifier.weight(1f)
+            )
+            FeatureTile(
+                feature = features[1],
+                modifier = Modifier.weight(1f)
+            )
+        }
+        Row(
+            modifier = Modifier.fillMaxWidth(),
+            horizontalArrangement = Arrangement.spacedBy(spacing.sm)
+        ) {
+            FeatureTile(
+                feature = features[2],
+                modifier = Modifier.weight(1f)
+            )
+            FeatureTile(
+                feature = features[3],
+                modifier = Modifier.weight(1f)
+            )
+        }
+    }
+}
+
+@Composable
+private fun FeatureTile(
+    feature: ProductFeature,
+    modifier: Modifier = Modifier
+) {
+    val spacing = CatalogTheme.spacing
+    // Stitch: bg-surface-container-low p-md rounded-2xl border border-outline-variant/30
+    Surface(
+        modifier = modifier.border(
+            width = 0.5.dp,
+            color = MaterialTheme.colorScheme.outlineVariant.copy(alpha = 0.3f),
+            shape = RoundedCornerShape(FEATURE_TILE_CORNER.dp)
+        ),
+        shape = RoundedCornerShape(FEATURE_TILE_CORNER.dp),
+        color = MaterialTheme.colorScheme.surfaceContainerLow
+    ) {
+        Column(
+            modifier = Modifier.padding(spacing.md),
+            horizontalAlignment = Alignment.CenterHorizontally,
+            verticalArrangement = Arrangement.spacedBy(spacing.xs)
+        ) {
+            Text(
+                text = feature.icon,
+                style = MaterialTheme.typography.titleLarge,
+                color = MaterialTheme.colorScheme.primary
+            )
+            Text(
+                text = feature.label,
+                style = MaterialTheme.typography.labelMedium,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+            Text(
+                text = feature.value,
+                style = MaterialTheme.typography.labelLarge,
+                fontWeight = FontWeight.SemiBold,
+                color = MaterialTheme.colorScheme.onSurface
+            )
+        }
+    }
+}
+
+@Preview(showBackground = true)
+@Composable
+internal fun DetailFeaturesGridPreview() {
+    CatalogTheme { DetailFeaturesGrid(product = previewProduct) }
+}
diff --git a/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailHeroImage.kt b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailHeroImage.kt
new file mode 100644
index 0000000..6390763
--- /dev/null
+++ b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailHeroImage.kt
@@ -0,0 +1,61 @@
+package com.example.catalogapp.feature.detail.components
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.aspectRatio
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Brush
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.tooling.preview.Preview
+import com.example.catalogapp.core.designsystem.components.CatalogAsyncImage
+import com.example.catalogapp.core.designsystem.components.DetailHeroImageDefaults.GRADIENT_START_FRACTION
+import com.example.catalogapp.core.designsystem.components.DetailHeroImageDefaults.HERO_ASPECT_HEIGHT
+import com.example.catalogapp.core.designsystem.components.DetailHeroImageDefaults.HERO_ASPECT_WIDTH
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+
+@Composable
+internal fun DetailHeroImage(
+    imageUrl: String,
+    title: String,
+    modifier: Modifier = Modifier
+) {
+    Box(
+        modifier = modifier
+            .fillMaxWidth()
+            // Stitch: aspect-[4/5] same as product card
+            .aspectRatio(HERO_ASPECT_WIDTH / HERO_ASPECT_HEIGHT)
+    ) {
+        CatalogAsyncImage(
+            imageUrl = imageUrl,
+            contentDescription = title,
+            modifier = Modifier.fillMaxSize()
+        )
+        // Stitch: bg-gradient-to-t from-surface via-transparent to-transparent opacity-60
+        // Gradient fades from surface color at bottom to transparent at top
+        Box(
+            modifier = Modifier
+                .fillMaxSize()
+                .background(
+                    brush = Brush.verticalGradient(
+                        colorStops = arrayOf(
+                            0f to Color.Transparent,
+                            GRADIENT_START_FRACTION to Color.Transparent,
+                            1f to MaterialTheme.colorScheme.surface.copy(alpha = 0.6f)
+                        )
+                    )
+                )
+        )
+    }
+}
+
+@Preview(showBackground = true)
+@Composable
+internal fun DetailHeroImagePreview() {
+    CatalogTheme {
+        DetailHeroImage(imageUrl = "", title = "Preview Product")
+    }
+}
diff --git a/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailPriceSection.kt b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailPriceSection.kt
new file mode 100644
index 0000000..4867bcc
--- /dev/null
+++ b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailPriceSection.kt
@@ -0,0 +1,65 @@
+package com.example.catalogapp.feature.detail.components
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextDecoration
+import androidx.compose.ui.tooling.preview.Preview
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+import java.util.Locale
+
+private const val DISCOUNT_PERCENT = 18
+private const val PERCENT_DIVISOR = 100.0
+
+@Composable
+internal fun DetailPriceSection(
+    price: Double,
+    modifier: Modifier = Modifier
+) {
+    val spacing = CatalogTheme.spacing
+    val originalPrice = price * (1 + DISCOUNT_PERCENT / PERCENT_DIVISOR)
+
+    // Stitch: flex items-baseline gap-md mt-lg
+    Row(
+        modifier = modifier
+            .fillMaxWidth()
+            .padding(horizontal = spacing.lg),
+        verticalAlignment = Alignment.Bottom,
+        horizontalArrangement = Arrangement.spacedBy(spacing.md)
+    ) {
+        // Stitch: text-headline-lg-mobile font-bold text-on-surface
+        Text(
+            text = "₹${String.format(Locale.getDefault(), "%,.0f", price)}",
+            style = MaterialTheme.typography.headlineMedium,
+            fontWeight = FontWeight.Bold,
+            color = MaterialTheme.colorScheme.onSurface
+        )
+        // Stitch: text-on-surface-variant line-through text-title-lg
+        Text(
+            text = "₹${String.format(Locale.getDefault(), "%,.0f", originalPrice)}",
+            style = MaterialTheme.typography.titleLarge,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            textDecoration = TextDecoration.LineThrough
+        )
+        // Stitch: text-secondary font-bold text-title-lg
+        Text(
+            text = "$DISCOUNT_PERCENT% OFF",
+            style = MaterialTheme.typography.titleLarge,
+            fontWeight = FontWeight.Bold,
+            color = MaterialTheme.colorScheme.secondary
+        )
+    }
+}
+
+@Preview(showBackground = true)
+@Composable
+internal fun DetailPriceSectionPreview() {
+    CatalogTheme { DetailPriceSection(price = 12999.0) }
+}
diff --git a/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailProductHeader.kt b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailProductHeader.kt
new file mode 100644
index 0000000..73be1cf
--- /dev/null
+++ b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailProductHeader.kt
@@ -0,0 +1,140 @@
+package com.example.catalogapp.feature.detail.components
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Star
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+import com.example.catalogapp.domain.product.Product
+import com.example.catalogapp.feature.detail.previewProduct
+import java.util.Locale
+
+private const val STAR_SIZE = 18
+private const val BADGE_DOT_SIZE = 8
+private const val EMERALD_LIGHT = 0xFFD1FAE5
+private const val EMERALD_DARK = 0xFF065F46
+private const val EMERALD_DOT = 0xFF059669
+
+@Composable
+internal fun DetailProductHeader(
+    product: Product,
+    modifier: Modifier = Modifier
+) {
+    val spacing = CatalogTheme.spacing
+    Column(
+        modifier = modifier.padding(spacing.lg),
+        verticalArrangement = Arrangement.spacedBy(spacing.sm)
+    ) {
+        // Stitch: text-primary font-label-lg tracking-widest uppercase
+        Text(
+            text = product.category.uppercase(),
+            style = MaterialTheme.typography.labelLarge,
+            color = MaterialTheme.colorScheme.primary,
+            letterSpacing = 3.sp,
+            fontWeight = FontWeight.Medium
+        )
+        // Stitch: font-headline-lg-mobile = Hanken Grotesk 28sp bold
+        Text(
+            text = product.title,
+            style = MaterialTheme.typography.headlineMedium,
+            color = MaterialTheme.colorScheme.onSurface,
+            fontWeight = FontWeight.Bold
+        )
+        Spacer(modifier = Modifier.height(spacing.xs))
+        Row(
+            horizontalArrangement = Arrangement.spacedBy(spacing.md),
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            RatingPill(rating = product.rating)
+            InStockBadge()
+        }
+    }
+}
+
+@Composable
+private fun RatingPill(rating: Float) {
+    val spacing = CatalogTheme.spacing
+    // Stitch: bg-surface-container-high px-3 py-1 rounded-full
+    Row(
+        modifier = Modifier
+            .background(
+                color = MaterialTheme.colorScheme.surfaceContainerHigh,
+                shape = CircleShape
+            )
+            .padding(horizontal = 12.dp, vertical = spacing.xs),
+        verticalAlignment = Alignment.CenterVertically,
+        horizontalArrangement = Arrangement.spacedBy(spacing.xs)
+    ) {
+        // Stitch: filled amber star 18sp
+        Icon(
+            imageVector = Icons.Default.Star,
+            contentDescription = null,
+            modifier = Modifier.size(STAR_SIZE.dp),
+            tint = MaterialTheme.colorScheme.secondary
+        )
+        Text(
+            text = String.format(Locale.getDefault(), "%.1f", rating),
+            style = MaterialTheme.typography.labelLarge,
+            fontWeight = FontWeight.Bold,
+            color = MaterialTheme.colorScheme.onSurface
+        )
+        Text(
+            text = "(${(rating * 200).toInt()} reviews)",
+            style = MaterialTheme.typography.labelMedium,
+            color = MaterialTheme.colorScheme.onSurfaceVariant
+        )
+    }
+}
+
+@Composable
+private fun InStockBadge() {
+    val spacing = CatalogTheme.spacing
+    // Stitch: bg-emerald-100 text-emerald-800 px-3 py-1 rounded-full with pulse dot
+    Row(
+        modifier = Modifier
+            .background(
+                color = Color(EMERALD_LIGHT),
+                shape = CircleShape
+            )
+            .padding(horizontal = 12.dp, vertical = spacing.xs),
+        verticalAlignment = Alignment.CenterVertically,
+        horizontalArrangement = Arrangement.spacedBy(spacing.xs)
+    ) {
+        Box(
+            modifier = Modifier
+                .size(BADGE_DOT_SIZE.dp)
+                .background(color = Color(EMERALD_DOT), shape = CircleShape)
+        )
+        Text(
+            text = "In Stock",
+            style = MaterialTheme.typography.labelLarge,
+            fontWeight = FontWeight.SemiBold,
+            color = Color(EMERALD_DARK)
+        )
+    }
+}
+
+@Preview(showBackground = true)
+@Composable
+internal fun DetailProductHeaderPreview() {
+    CatalogTheme { DetailProductHeader(product = previewProduct) }
+}
diff --git a/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailReviewsSection.kt b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailReviewsSection.kt
new file mode 100644
index 0000000..a37b069
--- /dev/null
+++ b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailReviewsSection.kt
@@ -0,0 +1,192 @@
+package com.example.catalogapp.feature.detail.components
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.border
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Star
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+
+private const val REVIEW_CARD_CORNER = 16
+private const val AVATAR_SIZE = 40
+private const val STAR_SIZE = 14
+private const val EMPTY_STAR_ALPHA = 0.2f
+private const val TOTAL_STARS = 5
+
+private data class ReviewData(
+    val name: String,
+    val rating: Int,
+    val review: String,
+    val date: String
+)
+
+private val sampleReviews = listOf(
+    ReviewData(
+        name = "Rohan Sharma",
+        rating = 5,
+        review = "\"The build quality is absolutely phenomenal. " +
+                "It feels much more expensive than it is. " +
+                "Highly recommend for anyone looking for a premium product.\"",
+        date = "2 days ago"
+    ),
+    ReviewData(
+        name = "Ananya Verma",
+        rating = 4,
+        review = "\"Absolutely love the battery life! " +
+                "The software is fluid and the tracking seems very accurate " +
+                "compared to my other devices.\"",
+        date = "1 week ago"
+    )
+)
+
+@Composable
+internal fun DetailReviewsSection(modifier: Modifier = Modifier) {
+    val spacing = CatalogTheme.spacing
+    Column(modifier = modifier.fillMaxWidth()) {
+        // Section header
+        Row(
+            modifier = Modifier.fillMaxWidth(),
+            horizontalArrangement = Arrangement.SpaceBetween,
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            Text(
+                text = "Customer Reviews",
+                style = MaterialTheme.typography.titleLarge,
+                color = MaterialTheme.colorScheme.onSurface
+            )
+            TextButton(onClick = { }) {
+                Text(
+                    text = "See All",
+                    style = MaterialTheme.typography.labelLarge,
+                    color = MaterialTheme.colorScheme.primary
+                )
+            }
+        }
+        Spacer(modifier = Modifier.height(spacing.md))
+        Column(verticalArrangement = Arrangement.spacedBy(spacing.md)) {
+            sampleReviews.forEach { review ->
+                ReviewCard(review = review)
+            }
+        }
+    }
+}
+
+@Composable
+private fun ReviewCard(review: ReviewData) {
+    val spacing = CatalogTheme.spacing
+    // Stitch: bg-surface-container p-lg rounded-2xl border border-outline-variant/20 shadow-sm
+    Column(
+        modifier = Modifier
+            .fillMaxWidth()
+            .background(
+                color = MaterialTheme.colorScheme.surfaceContainer,
+                shape = RoundedCornerShape(REVIEW_CARD_CORNER.dp)
+            )
+            .border(
+                width = 0.5.dp,
+                color = MaterialTheme.colorScheme.outlineVariant.copy(alpha = EMPTY_STAR_ALPHA),
+                shape = RoundedCornerShape(REVIEW_CARD_CORNER.dp)
+            )
+            .padding(spacing.lg)
+    ) {
+        Row(
+            modifier = Modifier.fillMaxWidth(),
+            horizontalArrangement = Arrangement.SpaceBetween,
+            verticalAlignment = Alignment.Top
+        ) {
+            Row(
+                horizontalArrangement = Arrangement.spacedBy(spacing.md),
+                verticalAlignment = Alignment.CenterVertically
+            ) {
+                ReviewerAvatar(name = review.name)
+                Column {
+                    Text(
+                        text = review.name,
+                        style = MaterialTheme.typography.labelLarge,
+                        fontWeight = FontWeight.Bold,
+                        color = MaterialTheme.colorScheme.onSurface
+                    )
+                    // Stitch: stars in text-secondary-container (amber)
+                    StarRow(rating = review.rating)
+                }
+            }
+            Text(
+                text = review.date,
+                style = MaterialTheme.typography.labelMedium,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+        }
+        Spacer(modifier = Modifier.height(spacing.md))
+        Text(
+            text = review.review,
+            style = MaterialTheme.typography.bodyMedium,
+            color = MaterialTheme.colorScheme.onSurfaceVariant
+        )
+    }
+}
+
+@Composable
+private fun ReviewerAvatar(name: String) {
+    // Stitch: w-10 h-10 rounded-full — initials avatar since we don't have real user images
+    Box(
+        modifier = Modifier
+            .size(AVATAR_SIZE.dp)
+            .background(
+                color = MaterialTheme.colorScheme.primaryContainer,
+                shape = CircleShape
+            ),
+        contentAlignment = Alignment.Center
+    ) {
+        Text(
+            text = name.first().toString(),
+            style = MaterialTheme.typography.titleSmall,
+            fontWeight = FontWeight.Bold,
+            color = MaterialTheme.colorScheme.onPrimaryContainer
+        )
+    }
+}
+
+@Composable
+private fun StarRow(rating: Int) {
+    Row(horizontalArrangement = Arrangement.spacedBy(1.dp)) {
+        repeat(TOTAL_STARS) { index ->
+            Icon(
+                imageVector = Icons.Default.Star,
+                contentDescription = null,
+                modifier = Modifier.size(STAR_SIZE.dp),
+                // Stitch: filled stars in secondary-container (amber), empty star muted
+                tint = if (index < rating) {
+                    MaterialTheme.colorScheme.secondaryContainer
+                } else {
+                    MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = EMPTY_STAR_ALPHA)
+                }
+            )
+        }
+    }
+}
+
+@Preview(showBackground = true)
+@Composable
+internal fun DetailReviewsSectionPreview() {
+    CatalogTheme { DetailReviewsSection() }
+}
diff --git a/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailTopBar.kt b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailTopBar.kt
new file mode 100644
index 0000000..1ad31b1
--- /dev/null
+++ b/feature/detail/src/main/java/com/example/catalogapp/feature/detail/components/DetailTopBar.kt
@@ -0,0 +1,102 @@
+package com.example.catalogapp.feature.detail.components
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.statusBarsPadding
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material.icons.filled.Share
+import androidx.compose.material.icons.filled.ShoppingCart
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.components.rememberDebouncedOnClick
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+
+private const val TOP_BAR_BUTTON_SIZE = 40
+
+@Composable
+internal fun DetailTopBar(
+    onBackClick: () -> Unit,
+    onShareClick: () -> Unit,
+    modifier: Modifier = Modifier
+) {
+    val spacing = CatalogTheme.spacing
+    // Stitch: fixed overlay, transparent, surface/20 circle buttons
+    Row(
+        modifier = modifier
+            .fillMaxWidth()
+            .statusBarsPadding()
+            .padding(horizontal = spacing.md, vertical = spacing.sm),
+        horizontalArrangement = Arrangement.SpaceBetween,
+        verticalAlignment = Alignment.CenterVertically
+    ) {
+        TopBarButton(
+            onClick = rememberDebouncedOnClick(onBackClick)
+        ) {
+            Icon(
+                imageVector = Icons.AutoMirrored.Filled.ArrowBack,
+                contentDescription = null,
+                modifier = Modifier.size(24.dp),
+                tint = MaterialTheme.colorScheme.onSurface
+            )
+        }
+
+        Row(horizontalArrangement = Arrangement.spacedBy(spacing.sm)) {
+            TopBarButton(onClick = rememberDebouncedOnClick(onShareClick)) {
+                Icon(
+                    imageVector = Icons.Default.Share,
+                    contentDescription = null,
+                    modifier = Modifier.size(24.dp),
+                    tint = MaterialTheme.colorScheme.onSurface
+                )
+            }
+            TopBarButton(onClick = rememberDebouncedOnClick { }) {
+                Icon(
+                    imageVector = Icons.Default.ShoppingCart,
+                    contentDescription = null,
+                    modifier = Modifier.size(24.dp),
+                    tint = MaterialTheme.colorScheme.onSurface
+                )
+            }
+        }
+    }
+}
+
+@Composable
+private fun TopBarButton(
+    onClick: () -> Unit,
+    content: @Composable () -> Unit
+) {
+    Box(
+        modifier = Modifier
+            .size(TOP_BAR_BUTTON_SIZE.dp)
+            .background(
+                color = MaterialTheme.colorScheme.surface.copy(alpha = 0.75f),
+                shape = CircleShape
+            )
+            .clickable { onClick() },
+        contentAlignment = Alignment.Center
+    ) {
+        content()
+    }
+}
+
+@Preview(showBackground = true)
+@Composable
+internal fun DetailTopBarPreview() {
+    CatalogTheme {
+        DetailTopBar(onBackClick = {}, onShareClick = {})
+    }
+}
diff --git a/feature/detail/src/test/java/com/example/catalogapp/feature/detail/DetailViewModelTest.kt b/feature/detail/src/test/java/com/example/catalogapp/feature/detail/DetailViewModelTest.kt
new file mode 100644
index 0000000..f57282d
--- /dev/null
+++ b/feature/detail/src/test/java/com/example/catalogapp/feature/detail/DetailViewModelTest.kt
@@ -0,0 +1,144 @@
+package com.example.catalogapp.feature.detail
+
+import com.example.catalogapp.domain.product.Product
+import com.example.catalogapp.domain.product.ProductRepository
+import io.mockk.coEvery
+import io.mockk.mockk
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.test.StandardTestDispatcher
+import kotlinx.coroutines.test.advanceUntilIdle
+import kotlinx.coroutines.test.resetMain
+import kotlinx.coroutines.test.runTest
+import kotlinx.coroutines.test.setMain
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Before
+import org.junit.Test
+
+@OptIn(ExperimentalCoroutinesApi::class)
+class DetailViewModelTest {
+
+    private val testDispatcher = StandardTestDispatcher()
+    private val productRepository: ProductRepository = mockk()
+    private lateinit var viewModel: DetailViewModel
+
+    private val fakeProduct = Product(
+        id = 1,
+        title = "Test Product",
+        price = 999.0,
+        description = "Test description",
+        category = "electronics",
+        imageUrl = "https://example.com/image.png",
+        rating = 4.5f
+    )
+
+    @Before
+    fun setUp() {
+        Dispatchers.setMain(testDispatcher)
+        viewModel = DetailViewModel(productRepository)
+    }
+
+    @After
+    fun tearDown() {
+        Dispatchers.resetMain()
+    }
+
+    @Test
+    fun `initial state is correct`() = runTest {
+        val state = viewModel.uiState.value
+        assertNull(state.product)
+        assertFalse(state.isLoading)
+        assertNull(state.error)
+        assertFalse(state.isWishlisted)
+        assertFalse(state.isDescriptionExpanded)
+    }
+
+    @Test
+    fun `LoadProduct sets loading then shows product on success`() = runTest {
+        coEvery { productRepository.getProductById(1) } returns fakeProduct
+
+        viewModel.processIntent(DetailIntent.LoadProduct(1))
+        advanceUntilIdle()
+
+        val state = viewModel.uiState.value
+        assertFalse(state.isLoading)
+        assertNotNull(state.product)
+        assertEquals("Test Product", state.product?.title)
+        assertTrue(state.showContent)
+        assertFalse(state.showLoading)
+        assertFalse(state.showError)
+    }
+
+    @Test
+    fun `LoadProduct sets error when product not found`() = runTest {
+        coEvery { productRepository.getProductById(99) } returns null
+
+        viewModel.processIntent(DetailIntent.LoadProduct(99))
+        advanceUntilIdle()
+
+        val state = viewModel.uiState.value
+        assertFalse(state.isLoading)
+        assertNull(state.product)
+        assertEquals("Product not found", state.error)
+        assertTrue(state.showError)
+    }
+
+    @Test
+    fun `ToggleWishlist toggles isWishlisted state`() = runTest {
+        coEvery { productRepository.getProductById(1) } returns fakeProduct
+        viewModel.processIntent(DetailIntent.LoadProduct(1))
+        advanceUntilIdle()
+
+        assertFalse(viewModel.uiState.value.isWishlisted)
+        viewModel.processIntent(DetailIntent.ToggleWishlist)
+        assertTrue(viewModel.uiState.value.isWishlisted)
+        viewModel.processIntent(DetailIntent.ToggleWishlist)
+        assertFalse(viewModel.uiState.value.isWishlisted)
+    }
+
+    @Test
+    fun `ToggleDescription toggles isDescriptionExpanded state`() = runTest {
+        assertFalse(viewModel.uiState.value.isDescriptionExpanded)
+        viewModel.processIntent(DetailIntent.ToggleDescription)
+        assertTrue(viewModel.uiState.value.isDescriptionExpanded)
+        viewModel.processIntent(DetailIntent.ToggleDescription)
+        assertFalse(viewModel.uiState.value.isDescriptionExpanded)
+    }
+
+    @Test
+    fun `NavigateBack sends NavigateBack effect`() = runTest {
+        viewModel.processIntent(DetailIntent.NavigateBack)
+        advanceUntilIdle()
+
+        var receivedEffect: DetailEffect? = null
+        val job = launch {
+            viewModel.effect.collect { receivedEffect = it }
+        }
+        advanceUntilIdle()
+        job.cancel()
+
+        assertTrue(receivedEffect is DetailEffect.NavigateBack)
+    }
+
+    @Test
+    fun `AddToCart sends ShowSnackbar effect with correct message`() = runTest {
+        viewModel.processIntent(DetailIntent.AddToCart)
+        advanceUntilIdle()
+
+        var receivedEffect: DetailEffect? = null
+        val job = launch {
+            viewModel.effect.collect { receivedEffect = it }
+        }
+        advanceUntilIdle()
+        job.cancel()
+
+        assertTrue(receivedEffect is DetailEffect.ShowSnackbar)
+        assertEquals("Added to cart", (receivedEffect as DetailEffect.ShowSnackbar).message)
+    }
+}
diff --git a/feature/detail/src/test/java/com/example/catalogapp/feature/detail/ExampleUnitTest.kt b/feature/detail/src/test/java/com/example/catalogapp/feature/detail/ExampleUnitTest.kt
new file mode 100644
index 0000000..20135a6
--- /dev/null
+++ b/feature/detail/src/test/java/com/example/catalogapp/feature/detail/ExampleUnitTest.kt
@@ -0,0 +1,17 @@
+package com.example.catalogapp.feature.detail
+
+import org.junit.Test
+
+import org.junit.Assert.*
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+class ExampleUnitTest {
+    @Test
+    fun addition_isCorrect() {
+        assertEquals(4, 2 + 2)
+    }
+}
diff --git a/feature/search/.gitignore b/feature/search/.gitignore
new file mode 100644
index 0000000..42afabf
--- /dev/null
+++ b/feature/search/.gitignore
@@ -0,0 +1 @@
+/build
\ No newline at end of file
diff --git a/feature/search/build.gradle.kts b/feature/search/build.gradle.kts
new file mode 100644
index 0000000..f998d99
--- /dev/null
+++ b/feature/search/build.gradle.kts
@@ -0,0 +1,79 @@
+plugins {
+    alias(libs.plugins.android.library)
+    alias(libs.plugins.kotlin.compose)
+    alias(libs.plugins.hilt)
+    alias(libs.plugins.ksp)
+    alias(libs.plugins.detekt)
+    jacoco
+}
+
+android {
+    namespace = "com.example.catalogapp.feature.search"
+    compileSdk {
+        version = release(36) {
+            minorApiLevel = 1
+        }
+    }
+
+    defaultConfig {
+        minSdk = 24
+
+        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+        consumerProguardFiles("consumer-rules.pro")
+    }
+
+    buildTypes {
+        release {
+            isMinifyEnabled = false
+            proguardFiles(
+                getDefaultProguardFile("proguard-android-optimize.txt"),
+                "proguard-rules.pro"
+            )
+        }
+    }
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
+    }
+
+    buildFeatures {
+        compose = true
+    }
+}
+
+jacoco {
+    toolVersion = "0.8.12"
+}
+
+detekt {
+    config.setFrom(files("$rootDir/config/detekt/detekt.yml"))
+    buildUponDefaultConfig = true
+    source.setFrom("src/main/java")
+}
+
+dependencies {
+    implementation(project(":domain:product"))
+    implementation(project(":core:common"))
+    implementation(project(":core:designsystem"))
+
+    implementation(platform(libs.androidx.compose.bom))
+    implementation(libs.androidx.compose.ui)
+    implementation(libs.androidx.compose.material3)
+    implementation(libs.androidx.compose.ui.tooling.preview)
+    implementation(libs.androidx.compose.foundation)
+    implementation(libs.androidx.compose.material.icons.extended)
+    implementation(libs.androidx.compose.ui.text)
+    debugImplementation(libs.androidx.compose.ui.tooling)
+
+    implementation(libs.androidx.lifecycle.runtime.ktx)
+    implementation(libs.hilt.android)
+    ksp(libs.hilt.compiler)
+    implementation(libs.hilt.navigation.compose)
+    implementation(libs.kotlinx.coroutines.android)
+    implementation(libs.coil.compose)
+
+    testImplementation(libs.junit)
+    testImplementation(libs.mockk)
+    testImplementation(libs.kotlinx.coroutines.test)
+}
+
diff --git a/feature/search/consumer-rules.pro b/feature/search/consumer-rules.pro
new file mode 100644
index 0000000..e69de29
diff --git a/feature/search/proguard-rules.pro b/feature/search/proguard-rules.pro
new file mode 100644
index 0000000..481bb43
--- /dev/null
+++ b/feature/search/proguard-rules.pro
@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile
\ No newline at end of file
diff --git a/feature/search/src/androidTest/java/com/example/catalogapp/feature/search/ExampleInstrumentedTest.kt b/feature/search/src/androidTest/java/com/example/catalogapp/feature/search/ExampleInstrumentedTest.kt
new file mode 100644
index 0000000..0215517
--- /dev/null
+++ b/feature/search/src/androidTest/java/com/example/catalogapp/feature/search/ExampleInstrumentedTest.kt
@@ -0,0 +1,24 @@
+package com.example.catalogapp.feature.search
+
+import androidx.test.platform.app.InstrumentationRegistry
+import androidx.test.ext.junit.runners.AndroidJUnit4
+
+import org.junit.Test
+import org.junit.runner.RunWith
+
+import org.junit.Assert.*
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+@RunWith(AndroidJUnit4::class)
+class ExampleInstrumentedTest {
+    @Test
+    fun useAppContext() {
+        // Context of the app under test.
+        val appContext = InstrumentationRegistry.getInstrumentation().targetContext
+        assertEquals("com.example.catalogapp.feature.search.test", appContext.packageName)
+    }
+}
diff --git a/feature/search/src/main/AndroidManifest.xml b/feature/search/src/main/AndroidManifest.xml
new file mode 100644
index 0000000..8bdb7e1
--- /dev/null
+++ b/feature/search/src/main/AndroidManifest.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+</manifest>
diff --git a/feature/search/src/main/java/com/example/catalogapp/feature/search/SearchContract.kt b/feature/search/src/main/java/com/example/catalogapp/feature/search/SearchContract.kt
new file mode 100644
index 0000000..49149bc
--- /dev/null
+++ b/feature/search/src/main/java/com/example/catalogapp/feature/search/SearchContract.kt
@@ -0,0 +1,28 @@
+package com.example.catalogapp.feature.search
+
+import com.example.catalogapp.domain.product.Product
+
+data class SearchUiState(
+    val query: String = "",
+    val allProducts: List<Product> = emptyList(),
+    val filteredProducts: List<Product> = emptyList(),
+    val recentSearches: List<String> = emptyList(),
+    val availableCategories: List<String> = emptyList(),
+    val isLoading: Boolean = false,
+    val hasSearched: Boolean = false,
+    val error: String? = null
+)
+
+sealed class SearchIntent {
+    data class QueryChanged(val query: String) : SearchIntent()
+    data object ClearQuery : SearchIntent()
+    data class ProductClicked(val productId: Int) : SearchIntent()
+    data class RecentSearchClicked(val query: String) : SearchIntent()
+    data object ClearRecentSearches : SearchIntent()
+    data object RetryLoad : SearchIntent()
+}
+
+sealed class SearchEffect {
+    data class NavigateToDetail(val productId: Int) : SearchEffect()
+    data object DismissKeyboard : SearchEffect()
+}
diff --git a/feature/search/src/main/java/com/example/catalogapp/feature/search/SearchScreen.kt b/feature/search/src/main/java/com/example/catalogapp/feature/search/SearchScreen.kt
new file mode 100644
index 0000000..2685ebf
--- /dev/null
+++ b/feature/search/src/main/java/com/example/catalogapp/feature/search/SearchScreen.kt
@@ -0,0 +1,202 @@
+package com.example.catalogapp.feature.search
+
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.WindowInsets
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.navigationBarsPadding
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.statusBarsPadding
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Scaffold
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalSoftwareKeyboardController
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import com.example.catalogapp.core.designsystem.components.CatalogEmptyState
+import com.example.catalogapp.core.designsystem.components.CatalogLoadingState
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+import com.example.catalogapp.domain.product.Product
+import com.example.catalogapp.feature.search.components.RecentSearchesSection
+import com.example.catalogapp.feature.search.components.SearchBar
+import com.example.catalogapp.feature.search.components.SearchErrorState
+import com.example.catalogapp.feature.search.components.SearchPromptState
+import com.example.catalogapp.feature.search.components.SearchResultsList
+
+@Composable
+fun SearchScreen(
+    onNavigateToDetail: (Int) -> Unit,
+    viewModel: SearchViewModel = hiltViewModel()
+) {
+    val uiState by viewModel.uiState.collectAsState()
+    val keyboardController = LocalSoftwareKeyboardController.current
+
+    LaunchedEffect(Unit) {
+        viewModel.effect.collect { effect ->
+            when (effect) {
+                is SearchEffect.NavigateToDetail -> onNavigateToDetail(effect.productId)
+                is SearchEffect.DismissKeyboard -> keyboardController?.hide()
+            }
+        }
+    }
+
+    SearchContent(
+        uiState = uiState,
+        onIntent = viewModel::processIntent
+    )
+
+}
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+internal fun SearchContent(
+    uiState: SearchUiState,
+    onIntent: (SearchIntent) -> Unit
+) {
+    Scaffold(
+        contentWindowInsets = WindowInsets(0, 0, 0, 0),
+        topBar = {
+            Box(
+                modifier = Modifier
+                    .statusBarsPadding()
+                    .padding(horizontal = 16.dp, vertical = 8.dp)
+            ) {
+                SearchBar(
+                    query = uiState.query,
+                    onQueryChanged = { onIntent(SearchIntent.QueryChanged(it)) },
+                    onClear = { onIntent(SearchIntent.ClearQuery) }
+                )
+            }
+        }
+    ) { paddingValues ->
+        Box(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(paddingValues)
+                .padding(horizontal = 16.dp)
+                .navigationBarsPadding()
+        ) {
+            when {
+                uiState.error != null -> SearchErrorState(
+                    message = uiState.error,
+                    onRetry = { onIntent(SearchIntent.RetryLoad) }
+                )
+
+                uiState.isLoading -> CatalogLoadingState()
+                uiState.query.isBlank() -> {
+                    if (uiState.recentSearches.isNotEmpty()) {
+                        RecentSearchesSection(
+                            recentSearches = uiState.recentSearches,
+                            onRecentClicked = { onIntent(SearchIntent.RecentSearchClicked(it)) },
+                            onClearAll = { onIntent(SearchIntent.ClearRecentSearches) }
+                        )
+                    } else {
+                        SearchPromptState(
+                            categories = uiState.availableCategories,
+                            onCategoryClicked = { onIntent(SearchIntent.RecentSearchClicked(it)) }
+                        )
+                    }
+                }
+
+                uiState.hasSearched && uiState.filteredProducts.isEmpty() -> CatalogEmptyState(
+                    message = "No products found."
+                )
+
+                else -> SearchResultsList(
+                    products = uiState.filteredProducts,
+                    onProductClicked = { onIntent(SearchIntent.ProductClicked(it)) }
+                )
+            }
+        }
+    }
+}
+
+@Preview(showBackground = true, name = "Content - error")
+@Composable
+internal fun SearchContentErrorPreview() {
+    CatalogTheme {
+        SearchContent(
+            uiState = SearchUiState(error = "Couldn't load products. Try again."),
+            onIntent = {}
+        )
+    }
+}
+
+@Preview(showBackground = true, name = "Content - loading")
+@Composable
+internal fun SearchContentLoadingPreview() {
+    CatalogTheme {
+        SearchContent(
+            uiState = SearchUiState(isLoading = true),
+            onIntent = {}
+        )
+    }
+}
+
+@Preview(showBackground = true, name = "Content - empty query, no recents")
+@Composable
+internal fun SearchContentEmptyQueryNoRecentsPreview() {
+    CatalogTheme {
+        SearchContent(
+            uiState = SearchUiState(),
+            onIntent = {}
+        )
+    }
+}
+
+@Preview(showBackground = true, name = "Content - empty query, with recents")
+@Composable
+internal fun SearchContentWithRecentsPreview() {
+    CatalogTheme {
+        SearchContent(
+            uiState = SearchUiState(
+                recentSearches = listOf("Silver earrings", "Running shoes")
+            ),
+            onIntent = {}
+        )
+    }
+}
+
+@Preview(showBackground = true, name = "Content - no results found")
+@Composable
+internal fun SearchContentNoResultsPreview() {
+    CatalogTheme {
+        SearchContent(
+            uiState = SearchUiState(
+                query = "xyz123",
+                hasSearched = true,
+                filteredProducts = emptyList()
+            ),
+            onIntent = {}
+        )
+    }
+}
+
+@Preview(showBackground = true, name = "Content - results found")
+@Composable
+internal fun SearchContentWithResultsPreview() {
+    CatalogTheme {
+        SearchContent(
+            uiState = SearchUiState(
+                query = "silver",
+                hasSearched = true,
+                filteredProducts = listOf(
+                    Product(
+                        id = 1,
+                        title = "Sleek Silver Drop Earrings",
+                        price = 120.0,
+                        description = "Minimalist silver drop earrings.",
+                        category = "Jewelry",
+                        imageUrl = "",
+                        rating = 4.8f
+                    )
+                )
+            ),
+            onIntent = {}
+        )
+    }
+}
diff --git a/feature/search/src/main/java/com/example/catalogapp/feature/search/SearchViewModel.kt b/feature/search/src/main/java/com/example/catalogapp/feature/search/SearchViewModel.kt
new file mode 100644
index 0000000..0569d5c
--- /dev/null
+++ b/feature/search/src/main/java/com/example/catalogapp/feature/search/SearchViewModel.kt
@@ -0,0 +1,120 @@
+package com.example.catalogapp.feature.search
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.example.catalogapp.domain.product.GetProductsUseCase
+import com.example.catalogapp.domain.product.SearchProductsUseCase
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.FlowPreview
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.catch
+import kotlinx.coroutines.flow.debounce
+import kotlinx.coroutines.flow.distinctUntilChanged
+import kotlinx.coroutines.flow.receiveAsFlow
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+private const val DEBOUNCE_MILLIS = 300L
+private const val MAX_RECENT_SEARCHES = 5
+private const val LOAD_ERROR_MESSAGE =
+    "Couldn't load products. Check your connection and try again."
+
+@HiltViewModel
+class SearchViewModel @Inject constructor(
+    private val getProductsUseCase: GetProductsUseCase,
+    private val searchProductsUseCase: SearchProductsUseCase
+) : ViewModel() {
+
+    private val _uiState = MutableStateFlow(SearchUiState())
+    val uiState: StateFlow<SearchUiState> = _uiState.asStateFlow()
+
+    private val _effect = Channel<SearchEffect>(Channel.BUFFERED)
+    val effect = _effect.receiveAsFlow()
+
+    private val queryFlow = MutableStateFlow("")
+
+    init {
+        loadCachedProducts()
+        observeQueryChanges()
+    }
+
+    fun processIntent(intent: SearchIntent) {
+        when (intent) {
+            is SearchIntent.QueryChanged -> onQueryChanged(intent.query)
+            is SearchIntent.ClearQuery -> onQueryChanged("")
+            is SearchIntent.ProductClicked -> onProductClicked(intent.productId)
+            is SearchIntent.RecentSearchClicked -> onQueryChanged(intent.query)
+            is SearchIntent.ClearRecentSearches -> clearRecentSearches()
+            is SearchIntent.RetryLoad -> loadCachedProducts()
+        }
+    }
+
+    private fun loadCachedProducts() {
+        viewModelScope.launch {
+            _uiState.update { it.copy(isLoading = true, error = null) }
+            getProductsUseCase()
+                .catch { exception ->
+                    _uiState.update {
+                        it.copy(isLoading = false, error = exception.message ?: LOAD_ERROR_MESSAGE)
+                    }
+                }
+                .collect { products ->
+                    _uiState.update {
+                        it.copy(
+                            allProducts = products,
+                            availableCategories = products.map { p -> p.category }.distinct(),
+                            isLoading = false,
+                            error = null
+                        )
+                    }
+                }
+        }
+    }
+
+    @OptIn(FlowPreview::class)
+    private fun observeQueryChanges() {
+        viewModelScope.launch {
+            queryFlow
+                .debounce(DEBOUNCE_MILLIS)
+                .distinctUntilChanged()
+                .collect { query -> filterProducts(query) }
+        }
+    }
+
+    private fun onQueryChanged(query: String) {
+        _uiState.update { it.copy(query = query) }
+        queryFlow.value = query
+    }
+
+    private fun filterProducts(query: String) {
+        if (query.isBlank()) {
+            _uiState.update { it.copy(filteredProducts = emptyList(), hasSearched = false) }
+            return
+        }
+        val currentState = _uiState.value
+        val matches = searchProductsUseCase(currentState.allProducts, query)
+        _uiState.update { it.copy(filteredProducts = matches, hasSearched = true) }
+        if (matches.isNotEmpty()) addRecentSearch(query)
+    }
+
+    private fun addRecentSearch(query: String) {
+        val updated = listOf(query) + _uiState.value.recentSearches.filterNot { it == query }
+        _uiState.update { it.copy(recentSearches = updated.take(MAX_RECENT_SEARCHES)) }
+    }
+
+    private fun clearRecentSearches() {
+        _uiState.update { it.copy(recentSearches = emptyList()) }
+    }
+
+    private fun onProductClicked(productId: Int) {
+        viewModelScope.launch {
+            _effect.send(SearchEffect.DismissKeyboard)
+            _effect.send(SearchEffect.NavigateToDetail(productId))
+        }
+    }
+}
+
diff --git a/feature/search/src/main/java/com/example/catalogapp/feature/search/components/RecentSearchesSection.kt b/feature/search/src/main/java/com/example/catalogapp/feature/search/components/RecentSearchesSection.kt
new file mode 100644
index 0000000..c91c331
--- /dev/null
+++ b/feature/search/src/main/java/com/example/catalogapp/feature/search/components/RecentSearchesSection.kt
@@ -0,0 +1,109 @@
+package com.example.catalogapp.feature.search.components
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.FlowRow
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.History
+import androidx.compose.material3.AssistChip
+import androidx.compose.material3.AssistChipDefaults
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.components.rememberDebouncedOnClick
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+
+private const val CHIP_CORNER_RADIUS_PERCENT = 50
+
+@Composable
+internal fun RecentSearchesSection(
+    recentSearches: List<String>,
+    onRecentClicked: (String) -> Unit,
+    onClearAll: () -> Unit
+) {
+    if (recentSearches.isEmpty()) return
+
+    Column {
+        Row(
+            modifier = Modifier.fillMaxWidth(),
+            horizontalArrangement = Arrangement.SpaceBetween,
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            Text(
+                text = "RECENT SEARCHES",
+                style = MaterialTheme.typography.labelMedium,
+                color = MaterialTheme.colorScheme.outline
+            )
+            TextButton(onClick = rememberDebouncedOnClick(onClearAll)) {
+                Text("Clear all")
+            }
+        }
+        FlowRow(
+            horizontalArrangement = Arrangement.spacedBy(8.dp),
+        ) {
+            recentSearches.forEach { search ->
+                RecentSearchChip(text = search, onClick = rememberDebouncedOnClick { onRecentClicked(search) })
+            }
+        }
+    }
+}
+
+@Composable
+private fun RecentSearchChip(text: String, onClick: () -> Unit) {
+    AssistChip(
+        onClick = onClick,
+        label = { Text(text) },
+        leadingIcon = { Icon(Icons.Default.History, contentDescription = null) },
+        shape = androidx.compose.foundation.shape.RoundedCornerShape(CHIP_CORNER_RADIUS_PERCENT),
+        colors = AssistChipDefaults.assistChipColors(
+            containerColor = MaterialTheme.colorScheme.surfaceContainerHigh
+        )
+    )
+}
+
+@Preview(showBackground = true, name = "RecentSearches - populated, wraps to 2 rows")
+@Composable
+internal fun RecentSearchesPopulatedPreview() {
+    CatalogTheme {
+        RecentSearchesSection(
+            recentSearches = listOf(
+                "Silver earrings", "Running shoes", "Smartwatch",
+                "Leather jacket", "Wireless headphones"
+            ),
+            onRecentClicked = {},
+            onClearAll = {}
+        )
+    }
+}
+
+@Preview(showBackground = true, name = "RecentSearches - single item")
+@Composable
+internal fun RecentSearchesSingleItemPreview() {
+    CatalogTheme {
+        RecentSearchesSection(
+            recentSearches = listOf("Silver earrings"),
+            onRecentClicked = {},
+            onClearAll = {}
+        )
+    }
+}
+
+@Preview(showBackground = true, name = "RecentSearches - empty (renders nothing)")
+@Composable
+internal fun RecentSearchesEmptyPreview() {
+    CatalogTheme {
+        RecentSearchesSection(
+            recentSearches = emptyList(),
+            onRecentClicked = {},
+            onClearAll = {}
+        )
+    }
+}
diff --git a/feature/search/src/main/java/com/example/catalogapp/feature/search/components/SearchBar.kt b/feature/search/src/main/java/com/example/catalogapp/feature/search/components/SearchBar.kt
new file mode 100644
index 0000000..79b8f20
--- /dev/null
+++ b/feature/search/src/main/java/com/example/catalogapp/feature/search/components/SearchBar.kt
@@ -0,0 +1,86 @@
+package com.example.catalogapp.feature.search.components
+
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.text.KeyboardActions
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Close
+import androidx.compose.material.icons.filled.Search
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.OutlinedTextFieldDefaults
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.focus.FocusRequester
+import androidx.compose.ui.focus.focusRequester
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.input.ImeAction
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.components.rememberDebouncedOnClick
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+
+private val SEARCH_BAR_CORNER_RADIUS = 28.dp
+
+@Composable
+fun SearchBar(
+    query: String,
+    onQueryChanged: (String) -> Unit,
+    onClear: () -> Unit
+) {
+    val focusRequester = remember { FocusRequester() }
+
+    LaunchedEffect(Unit) {
+        focusRequester.requestFocus()
+    }
+
+    OutlinedTextField(
+        value = query,
+        onValueChange = onQueryChanged,
+        modifier = Modifier
+            .fillMaxWidth()
+            .focusRequester(focusRequester),
+        shape = RoundedCornerShape(SEARCH_BAR_CORNER_RADIUS),
+        placeholder = { Text("Search products...", style = MaterialTheme.typography.bodyLarge) },
+        leadingIcon = { Icon(Icons.Default.Search, contentDescription = null) },
+        trailingIcon = {
+            if (query.isNotEmpty()) {
+                IconButton(onClick = rememberDebouncedOnClick(onClear)) {
+                    Icon(Icons.Default.Close, contentDescription = "Clear search")
+                }
+            }
+        },
+        singleLine = true,
+        textStyle = MaterialTheme.typography.bodyLarge,
+        keyboardOptions = KeyboardOptions(imeAction = ImeAction.Search),
+        keyboardActions = KeyboardActions(onSearch = { }),
+        colors = OutlinedTextFieldDefaults.colors(
+            unfocusedContainerColor = MaterialTheme.colorScheme.surfaceContainerHigh,
+            focusedContainerColor = MaterialTheme.colorScheme.surfaceContainerHigh,
+            unfocusedBorderColor = Color.Transparent,
+            focusedBorderColor = MaterialTheme.colorScheme.primary
+        )
+    )
+}
+
+@Preview(showBackground = true, name = "SearchBar - empty")
+@Composable
+internal fun SearchBarEmptyPreview() {
+    CatalogTheme {
+        SearchBar(query = "", onQueryChanged = {}, onClear = {})
+    }
+}
+
+@Preview(showBackground = true, name = "SearchBar - with query")
+@Composable
+internal fun SearchBarWithQueryPreview() {
+    CatalogTheme {
+        SearchBar(query = "silver earrings", onQueryChanged = {}, onClear = {})
+    }
+}
diff --git a/feature/search/src/main/java/com/example/catalogapp/feature/search/components/SearchErrorState.kt b/feature/search/src/main/java/com/example/catalogapp/feature/search/components/SearchErrorState.kt
new file mode 100644
index 0000000..47d0cef
--- /dev/null
+++ b/feature/search/src/main/java/com/example/catalogapp/feature/search/components/SearchErrorState.kt
@@ -0,0 +1,55 @@
+package com.example.catalogapp.feature.search.components
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ErrorOutline
+import androidx.compose.material3.Button
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.components.rememberDebouncedOnClick
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+
+@Composable
+fun SearchErrorState(message: String, onRetry: () -> Unit) {
+    Column(
+        modifier = Modifier
+            .fillMaxWidth()
+            .padding(top = 64.dp),
+        horizontalAlignment = Alignment.CenterHorizontally
+    ) {
+        Icon(
+            Icons.Default.ErrorOutline,
+            contentDescription = null,
+            tint = MaterialTheme.colorScheme.error,
+            modifier = Modifier.size(48.dp)
+        )
+        Spacer(modifier = Modifier.height(16.dp))
+        Text(text = message, style = MaterialTheme.typography.bodyMedium)
+        Spacer(modifier = Modifier.height(16.dp))
+        Button(onClick = rememberDebouncedOnClick(onRetry)) {
+            Text("Retry")
+        }
+    }
+}
+
+@Preview(showBackground = true, name = "ErrorState")
+@Composable
+internal fun SearchErrorStatePreview() {
+    CatalogTheme {
+        SearchErrorState(
+            message = "Couldn't load products. Check your connection and try again.",
+            onRetry = {}
+        )
+    }
+}
diff --git a/feature/search/src/main/java/com/example/catalogapp/feature/search/components/SearchPromptState.kt b/feature/search/src/main/java/com/example/catalogapp/feature/search/components/SearchPromptState.kt
new file mode 100644
index 0000000..c1c944e
--- /dev/null
+++ b/feature/search/src/main/java/com/example/catalogapp/feature/search/components/SearchPromptState.kt
@@ -0,0 +1,87 @@
+package com.example.catalogapp.feature.search.components
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.FlowRow
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Search
+import androidx.compose.material3.AssistChip
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.components.rememberDebouncedOnClick
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+
+private val PROMPT_TOP_PADDING = 48.dp
+private val PROMPT_ICON_SIZE = 64.dp
+
+@Composable
+internal fun SearchPromptState(
+    categories: List<String>,
+    onCategoryClicked: (String) -> Unit
+) {
+    Column(
+        modifier = Modifier
+            .fillMaxWidth()
+            .padding(top = PROMPT_TOP_PADDING),
+        horizontalAlignment = Alignment.CenterHorizontally
+    ) {
+        Icon(
+            Icons.Default.Search,
+            contentDescription = null,
+            tint = MaterialTheme.colorScheme.outlineVariant,
+            modifier = Modifier.size(PROMPT_ICON_SIZE)
+        )
+        Spacer(modifier = Modifier.height(16.dp))
+        Text(
+            text = "Search for products",
+            style = MaterialTheme.typography.titleMedium
+        )
+        Text(
+            text = "Try a name, or browse a category below",
+            style = MaterialTheme.typography.bodyMedium,
+            color = MaterialTheme.colorScheme.onSurfaceVariant
+        )
+        Spacer(modifier = Modifier.height(24.dp))
+        FlowRow(horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+            categories.forEach { category ->
+                AssistChip(
+                    onClick = rememberDebouncedOnClick { onCategoryClicked(category) },
+                    label = { Text(category) }
+                )
+            }
+        }
+    }
+}
+
+@Preview(showBackground = true, name = "SearchPromptState - with categories")
+@Composable
+internal fun SearchPromptStatePreview() {
+    CatalogTheme {
+        SearchPromptState(
+            categories = listOf("Electronics", "Jewelry", "Footwear", "Men's Clothing"),
+            onCategoryClicked = {}
+        )
+    }
+}
+
+@Preview(showBackground = true, name = "SearchPromptState - single category")
+@Composable
+internal fun SearchPromptStateSingleCategoryPreview() {
+    CatalogTheme {
+        SearchPromptState(
+            categories = listOf("Electronics"),
+            onCategoryClicked = {}
+        )
+    }
+}
diff --git a/feature/search/src/main/java/com/example/catalogapp/feature/search/components/SearchResultCard.kt b/feature/search/src/main/java/com/example/catalogapp/feature/search/components/SearchResultCard.kt
new file mode 100644
index 0000000..d3b8b2e
--- /dev/null
+++ b/feature/search/src/main/java/com/example/catalogapp/feature/search/components/SearchResultCard.kt
@@ -0,0 +1,126 @@
+package com.example.catalogapp.feature.search.components
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.RowScope
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ChevronRight
+import androidx.compose.material.icons.filled.Star
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.platform.LocalLocale
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.components.CatalogAsyncImage
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+import com.example.catalogapp.domain.product.Product
+
+private val CARD_CORNER_RADIUS = 12.dp
+private val IMAGE_SIZE = 96.dp
+
+@Composable
+fun SearchResultCard(product: Product, onClick: () -> Unit) {
+    Row(
+        modifier = Modifier
+            .fillMaxWidth()
+            .clip(RoundedCornerShape(CARD_CORNER_RADIUS))
+            .background(MaterialTheme.colorScheme.surfaceContainerLowest)
+            .clickable(onClick = onClick)
+            .padding(8.dp),
+        verticalAlignment = Alignment.CenterVertically
+    ) {
+        CatalogAsyncImage(
+            imageUrl = product.imageUrl,
+            contentDescription = product.title,
+            modifier = Modifier
+                .size(IMAGE_SIZE)
+                .clip(RoundedCornerShape(8.dp))
+                .background(MaterialTheme.colorScheme.surfaceVariant)
+        )
+        Spacer(modifier = Modifier.width(16.dp))
+        SearchResultInfo(product)
+        Icon(Icons.Default.ChevronRight, contentDescription = null)
+    }
+}
+
+@Composable
+private fun RowScope.SearchResultInfo(product: Product) {
+    Column(modifier = Modifier.weight(1f)) {
+        Row(
+            modifier = Modifier.fillMaxWidth(),
+            horizontalArrangement = Arrangement.SpaceBetween
+        ) {
+            Text(
+                text = product.category.uppercase(LocalLocale.current.platformLocale),
+                style = MaterialTheme.typography.titleMedium,
+                color = MaterialTheme.colorScheme.secondary
+            )
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                Icon(
+                    Icons.Default.Star,
+                    contentDescription = null,
+                    tint = MaterialTheme.colorScheme.secondaryContainer,
+                    modifier = Modifier.size(16.dp)
+                )
+                Text(
+                    text = String.format(
+                        LocalLocale.current.platformLocale,
+                        "%.1f",
+                        product.rating,
+                    ),
+                    style = MaterialTheme.typography.labelMedium,
+                    color = MaterialTheme.colorScheme.secondaryContainer
+                )
+            }
+        }
+        Text(
+            text = product.title,
+            style = MaterialTheme.typography.titleSmall,
+            maxLines = 1,
+            overflow = TextOverflow.Ellipsis,
+            modifier = Modifier.padding(top = 4.dp)
+        )
+        Spacer(modifier = Modifier.height(4.dp))
+        Text(
+            text =
+                String.format(LocalLocale.current.platformLocale, "$%.2f", product.price),
+            style = MaterialTheme.typography.bodyMedium,
+            color = MaterialTheme.colorScheme.primary
+        )
+    }
+}
+
+@Preview(showBackground = true, name = "ResultCard - long title")
+@Composable
+internal fun SearchResultCardLongTitlePreview() {
+    CatalogTheme {
+        SearchResultCard(
+            product = Product(
+                id = 1,
+                title = "Extremely Long Product Title That Might Wrap To Two Lines",
+                price = 999.99,
+                description = "A product with a very long name to test text wrapping.",
+                category = "Electronics",
+                imageUrl = "",
+                rating = 4.5f
+            ),
+            onClick = {}
+        )
+    }
+}
diff --git a/feature/search/src/main/java/com/example/catalogapp/feature/search/components/SearchResultsList.kt b/feature/search/src/main/java/com/example/catalogapp/feature/search/components/SearchResultsList.kt
new file mode 100644
index 0000000..cd85f4b
--- /dev/null
+++ b/feature/search/src/main/java/com/example/catalogapp/feature/search/components/SearchResultsList.kt
@@ -0,0 +1,89 @@
+package com.example.catalogapp.feature.search.components
+
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import com.example.catalogapp.core.designsystem.components.rememberDebouncedOnClick
+import com.example.catalogapp.core.designsystem.theme.CatalogTheme
+import com.example.catalogapp.domain.product.Product
+
+@Composable
+fun SearchResultsList(
+    products: List<Product>,
+    onProductClicked: (Int) -> Unit
+) {
+    LazyColumn(
+        contentPadding = PaddingValues(vertical = 16.dp),
+        verticalArrangement = Arrangement.spacedBy(12.dp)
+    ) {
+        items(products, key = { it.id }) { product ->
+            SearchResultCard(
+                product = product,
+                onClick = rememberDebouncedOnClick { onProductClicked(product.id) })
+        }
+    }
+}
+
+@Preview(showBackground = true, name = "ResultsList - multiple items")
+@Composable
+internal fun SearchResultsListPreview() {
+    CatalogTheme {
+        SearchResultsList(
+            products = listOf(
+                Product(
+                    id = 1,
+                    title = "Sleek Silver Drop Earrings",
+                    price = 120.0,
+                    description = "Minimalist silver drop earrings.",
+                    category = "Jewelry",
+                    imageUrl = "",
+                    rating = 4.8f
+                ),
+                Product(
+                    id = 2,
+                    title = "Nitro Pulse Runner Pro",
+                    price = 185.0,
+                    description = "High-performance running shoes.",
+                    category = "Footwear",
+                    imageUrl = "",
+                    rating = 4.9f
+                ),
+                Product(
+                    id = 3,
+                    title = "Aura Smartwatch Gen-4",
+                    price = 349.99,
+                    description = "Fitness-focused smartwatch.",
+                    category = "Electronics",
+                    imageUrl = "",
+                    rating = 4.7f
+                )
+            ),
+            onProductClicked = {}
+        )
+    }
+}
+
+@Preview(showBackground = true, name = "ResultsList - single item")
+@Composable
+internal fun SearchResultsListSingleItemPreview() {
+    CatalogTheme {
+        SearchResultsList(
+            products = listOf(
+                Product(
+                    id = 1,
+                    title = "Sleek Silver Drop Earrings",
+                    price = 120.0,
+                    description = "Minimalist silver drop earrings.",
+                    category = "Jewelry",
+                    imageUrl = "",
+                    rating = 4.8f
+                )
+            ),
+            onProductClicked = {}
+        )
+    }
+}
diff --git a/feature/search/src/test/java/com/example/catalogapp/feature/search/ExampleUnitTest.kt b/feature/search/src/test/java/com/example/catalogapp/feature/search/ExampleUnitTest.kt
new file mode 100644
index 0000000..fdb0736
--- /dev/null
+++ b/feature/search/src/test/java/com/example/catalogapp/feature/search/ExampleUnitTest.kt
@@ -0,0 +1,17 @@
+package com.example.catalogapp.feature.search
+
+import org.junit.Test
+
+import org.junit.Assert.*
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+class ExampleUnitTest {
+    @Test
+    fun addition_isCorrect() {
+        assertEquals(4, 2 + 2)
+    }
+}
diff --git a/feature/search/src/test/java/com/example/catalogapp/feature/search/SearchViewModelTest.kt b/feature/search/src/test/java/com/example/catalogapp/feature/search/SearchViewModelTest.kt
new file mode 100644
index 0000000..2b45bf2
--- /dev/null
+++ b/feature/search/src/test/java/com/example/catalogapp/feature/search/SearchViewModelTest.kt
@@ -0,0 +1,260 @@
+package com.example.catalogapp.feature.search
+
+import com.example.catalogapp.domain.product.GetProductsUseCase
+import com.example.catalogapp.domain.product.Product
+import com.example.catalogapp.domain.product.SearchProductsUseCase
+import io.mockk.coEvery
+import io.mockk.every
+import io.mockk.mockk
+import junit.framework.TestCase.assertEquals
+import junit.framework.TestCase.assertNull
+import junit.framework.TestCase.assertTrue
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.flowOf
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.test.StandardTestDispatcher
+import kotlinx.coroutines.test.resetMain
+import kotlinx.coroutines.test.runTest
+import kotlinx.coroutines.test.setMain
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+
+@ExperimentalCoroutinesApi
+class SearchViewModelTest {
+
+    private val testDispatcher = StandardTestDispatcher()
+    private lateinit var getProductsUseCase: GetProductsUseCase
+    private lateinit var searchProductsUseCase: SearchProductsUseCase
+    private lateinit var viewModel: SearchViewModel
+
+    private val sampleProducts = listOf(
+        Product(
+            id = 1, title = "Silver Earrings", price = 120.0,
+            description = "d", category = "Jewelry", imageUrl = "", rating = 4.8f
+        ),
+        Product(
+            id = 2, title = "Running Shoes", price = 185.0,
+            description = "d", category = "Footwear", imageUrl = "", rating = 4.9f
+        )
+    )
+
+    @Before
+    fun setup() {
+        Dispatchers.setMain(testDispatcher)
+        getProductsUseCase = mockk()
+        searchProductsUseCase = mockk()
+        coEvery { getProductsUseCase() } returns flowOf(sampleProducts)
+        viewModel = SearchViewModel(getProductsUseCase, searchProductsUseCase)
+    }
+
+    @After
+    fun tearDown() {
+        Dispatchers.resetMain()
+    }
+
+    // --- Loading ---
+
+    @Test
+    fun `cached products load successfully on init`() = runTest(testDispatcher) {
+        testDispatcher.scheduler.advanceUntilIdle()
+
+        val state = viewModel.uiState.value
+        assertEquals(2, state.allProducts.size)
+        assertTrue(!state.isLoading)
+        assertNull(state.error)
+    }
+
+    @Test
+    fun `available categories are derived and deduplicated from loaded products`() =
+        runTest(testDispatcher) {
+            testDispatcher.scheduler.advanceUntilIdle()
+
+            val categories = viewModel.uiState.value.availableCategories
+            assertEquals(2, categories.size)
+            assertTrue(categories.contains("Jewelry"))
+            assertTrue(categories.contains("Footwear"))
+        }
+
+    // --- Debounce — proves timing, delegates matching to the mocked use case ---
+
+    @Test
+    fun `debounce - use case only invoked after 300ms of no new input`() = runTest(testDispatcher) {
+        every { searchProductsUseCase(any(), any()) } returns listOf(sampleProducts[0])
+        testDispatcher.scheduler.advanceUntilIdle()
+
+        viewModel.processIntent(SearchIntent.QueryChanged("s"))
+        testDispatcher.scheduler.advanceTimeBy(100)
+        viewModel.processIntent(SearchIntent.QueryChanged("si"))
+        testDispatcher.scheduler.advanceTimeBy(100)
+        viewModel.processIntent(SearchIntent.QueryChanged("silver"))
+
+        assertTrue(viewModel.uiState.value.filteredProducts.isEmpty())
+
+        testDispatcher.scheduler.advanceTimeBy(301)
+        assertEquals(1, viewModel.uiState.value.filteredProducts.size)
+    }
+
+    @Test
+    fun `rapid clear then retype does not leak a stale filter result`() = runTest(testDispatcher) {
+        every { searchProductsUseCase(any(), "shoes") } returns listOf(sampleProducts[1])
+        every { searchProductsUseCase(any(), "silver") } returns listOf(sampleProducts[0])
+        testDispatcher.scheduler.advanceUntilIdle()
+
+        viewModel.processIntent(SearchIntent.QueryChanged("shoes"))
+        testDispatcher.scheduler.advanceTimeBy(50)
+        viewModel.processIntent(SearchIntent.ClearQuery)
+        testDispatcher.scheduler.advanceTimeBy(50)
+        viewModel.processIntent(SearchIntent.QueryChanged("silver"))
+        testDispatcher.scheduler.advanceTimeBy(301)
+
+        val state = viewModel.uiState.value
+        assertEquals(1, state.filteredProducts.size)
+        assertEquals("Silver Earrings", state.filteredProducts.first().title)
+    }
+
+    // --- State transitions around the use case boundary ---
+
+    @Test
+    fun `empty query resets filtered results and hasSearched without calling use case`() =
+        runTest(testDispatcher) {
+            testDispatcher.scheduler.advanceUntilIdle()
+
+            viewModel.processIntent(SearchIntent.ClearQuery)
+            testDispatcher.scheduler.advanceTimeBy(301)
+
+            val state = viewModel.uiState.value
+            assertTrue(state.filteredProducts.isEmpty())
+            assertTrue(!state.hasSearched)
+        }
+
+    @Test
+    fun `no matches from use case sets hasSearched true with empty results`() =
+        runTest(testDispatcher) {
+            every { searchProductsUseCase(any(), any()) } returns emptyList()
+            testDispatcher.scheduler.advanceUntilIdle()
+
+            viewModel.processIntent(SearchIntent.QueryChanged("nonexistent"))
+            testDispatcher.scheduler.advanceTimeBy(301)
+
+            val state = viewModel.uiState.value
+            assertTrue(state.filteredProducts.isEmpty())
+            assertTrue(state.hasSearched)
+        }
+
+    // --- Recent searches ---
+
+    @Test
+    fun `successful match adds query to recent searches`() = runTest(testDispatcher) {
+        every { searchProductsUseCase(any(), any()) } returns listOf(sampleProducts[1])
+        testDispatcher.scheduler.advanceUntilIdle()
+
+        viewModel.processIntent(SearchIntent.QueryChanged("shoes"))
+        testDispatcher.scheduler.advanceTimeBy(301)
+
+        assertTrue(viewModel.uiState.value.recentSearches.contains("shoes"))
+    }
+
+    @Test
+    fun `query with no matches is not added to recent searches`() = runTest(testDispatcher) {
+        every { searchProductsUseCase(any(), any()) } returns emptyList()
+        testDispatcher.scheduler.advanceUntilIdle()
+
+        viewModel.processIntent(SearchIntent.QueryChanged("nonexistent"))
+        testDispatcher.scheduler.advanceTimeBy(301)
+
+        assertTrue(viewModel.uiState.value.recentSearches.isEmpty())
+    }
+
+    @Test
+    fun `duplicate recent search moves to front instead of duplicating`() =
+        runTest(testDispatcher) {
+            every { searchProductsUseCase(any(), "shoes") } returns listOf(sampleProducts[1])
+            every { searchProductsUseCase(any(), "silver") } returns listOf(sampleProducts[0])
+            testDispatcher.scheduler.advanceUntilIdle()
+
+            viewModel.processIntent(SearchIntent.QueryChanged("shoes"))
+            testDispatcher.scheduler.advanceTimeBy(301)
+            viewModel.processIntent(SearchIntent.QueryChanged("silver"))
+            testDispatcher.scheduler.advanceTimeBy(301)
+            viewModel.processIntent(SearchIntent.QueryChanged("shoes"))
+            testDispatcher.scheduler.advanceTimeBy(301)
+
+            val recents = viewModel.uiState.value.recentSearches
+            assertEquals("shoes", recents.first())
+            assertEquals(1, recents.count { it == "shoes" })
+        }
+
+    @Test
+    fun `clear recent searches empties the list`() = runTest(testDispatcher) {
+        every { searchProductsUseCase(any(), any()) } returns listOf(sampleProducts[1])
+        testDispatcher.scheduler.advanceUntilIdle()
+
+        viewModel.processIntent(SearchIntent.QueryChanged("shoes"))
+        testDispatcher.scheduler.advanceTimeBy(301)
+        viewModel.processIntent(SearchIntent.ClearRecentSearches)
+
+        assertTrue(viewModel.uiState.value.recentSearches.isEmpty())
+    }
+
+    @Test
+    fun `recent search click re-triggers filter for that query`() = runTest(testDispatcher) {
+        every { searchProductsUseCase(any(), "silver") } returns listOf(sampleProducts[0])
+        testDispatcher.scheduler.advanceUntilIdle()
+
+        viewModel.processIntent(SearchIntent.RecentSearchClicked("silver"))
+        testDispatcher.scheduler.advanceTimeBy(301)
+
+        val state = viewModel.uiState.value
+        assertEquals("silver", state.query)
+        assertEquals(1, state.filteredProducts.size)
+    }
+
+    // --- Effects ---
+
+    @Test
+    fun `product click emits DismissKeyboard then NavigateToDetail effects`() =
+        runTest(testDispatcher) {
+            val effects = mutableListOf<SearchEffect>()
+            val job = launch { viewModel.effect.collect { effects.add(it) } }
+
+            viewModel.processIntent(SearchIntent.ProductClicked(1))
+            testDispatcher.scheduler.advanceUntilIdle()
+
+            assertEquals(SearchEffect.DismissKeyboard, effects[0])
+            assertEquals(SearchEffect.NavigateToDetail(1), effects[1])
+            job.cancel()
+        }
+
+    // --- Error / retry ---
+
+    @Test
+    fun `load failure sets error state and clears loading`() = runTest(testDispatcher) {
+        coEvery { getProductsUseCase() } returns flow { throw Exception("network down") }
+        val vm = SearchViewModel(getProductsUseCase, searchProductsUseCase)
+        testDispatcher.scheduler.advanceUntilIdle()
+
+        val state = vm.uiState.value
+        assertTrue(state.error != null)
+        assertTrue(!state.isLoading)
+    }
+
+    @Test
+    fun `retry after failure reloads products successfully`() = runTest(testDispatcher) {
+        coEvery { getProductsUseCase() } returns flow { throw Exception("network down") }
+        val vm = SearchViewModel(getProductsUseCase, searchProductsUseCase)
+        testDispatcher.scheduler.advanceUntilIdle()
+        assertTrue(vm.uiState.value.error != null)
+
+        coEvery { getProductsUseCase() } returns flowOf(sampleProducts)
+        vm.processIntent(SearchIntent.RetryLoad)
+        testDispatcher.scheduler.advanceUntilIdle()
+
+        val state = vm.uiState.value
+        assertNull(state.error)
+        assertEquals(2, state.allProducts.size)
+    }
+}
+
diff --git a/gradle.properties b/gradle.properties
index 2d6942d..edaaf1c 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -13,3 +13,4 @@ org.gradle.jvmargs=-Xmx2048m -Dfile.encoding=UTF-8
 # org.gradle.parallel=true
 # Kotlin code style for this project: "official" or "obsolete":
 kotlin.code.style=official
+org.gradle.configuration-cache=true
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index d5025de..48ddfd6 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -1,6 +1,7 @@
 [versions]
 agp = "9.1.1"
 coreKtx = "1.15.0"
+coil = "2.7.0"
 junit = "4.13.2"
 junitVersion = "1.3.0"
 espressoCore = "3.7.0"
@@ -11,7 +12,8 @@ composeBom = "2024.09.00"
 coroutines = "1.9.0"
 retrofit = "2.11.0"
 okhttp = "4.12.0"
-room = "2.6.1"
+robolectric = "4.14.1"
+room = "2.8.4"
 lifecycle = "2.8.7"
 navigation = "2.8.5"
 mockk = "1.13.13"
@@ -19,9 +21,19 @@ appcompat = "1.7.1"
 material = "1.14.0"
 hilt = "2.59.2"
 ksp = "2.3.6"
+detekt = "1.23.7"
+kotlin-serialization = "2.2.10"
+foundation = "1.11.4"
+uiText = "1.11.4"
+workmanager = "2.9.1"
+hilt-work = "1.2.0"
+gson = "2.11.0"
+workTesting = "2.11.2"
+coreKtxVersion = "1.7.0"
 
 [libraries]
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
+androidx-work-testing = { module = "androidx.work:work-testing", version.ref = "workTesting" }
 junit = { group = "junit", name = "junit", version.ref = "junit" }
 androidx-junit = { group = "androidx.test.ext", name = "junit", version.ref = "junitVersion" }
 androidx-espresso-core = { group = "androidx.test.espresso", name = "espresso-core", version.ref = "espressoCore" }
@@ -48,6 +60,24 @@ androidx-appcompat = { group = "androidx.appcompat", name = "appcompat", version
 material = { group = "com.google.android.material", name = "material", version.ref = "material" }
 hilt-android = { group = "com.google.dagger", name = "hilt-android", version.ref = "hilt" }
 hilt-compiler = { group = "com.google.dagger", name = "hilt-android-compiler", version.ref = "hilt" }
+robolectric = { module = "org.robolectric:robolectric", version.ref = "robolectric" }
+room-runtime = { group = "androidx.room", name = "room-runtime", version.ref = "room" }
+room-ktx = { group = "androidx.room", name = "room-ktx", version.ref = "room" }
+room-compiler = { group = "androidx.room", name = "room-compiler", version.ref = "room" }
+androidx-google-fonts = { group = "androidx.compose.ui", name = "ui-text-google-fonts", version = "1.7.8" }
+hilt-navigation-compose = { group = "androidx.hilt", name = "hilt-navigation-compose", version = "1.2.0" }
+lifecycle-viewmodel-compose = { group = "androidx.lifecycle", name = "lifecycle-viewmodel-compose", version.ref = "lifecycle" }
+coil-compose = { group = "io.coil-kt", name = "coil-compose", version.ref = "coil" }
+androidx-navigation-compose = { group = "androidx.navigation", name = "navigation-compose", version.ref = "navigation" }
+androidx-compose-material-icons-extended = { group = "androidx.compose.material", name = "material-icons-extended" }
+kotlinx-serialization-json = { group = "org.jetbrains.kotlinx", name = "kotlinx-serialization-json", version = "1.7.3" }
+androidx-compose-foundation = { group = "androidx.compose.foundation", name = "foundation", version.ref = "foundation" }
+androidx-compose-ui-text = { group = "androidx.compose.ui", name = "ui-text", version.ref = "uiText" }
+androidx-work-runtime-ktx = { group = "androidx.work", name = "work-runtime-ktx", version.ref = "workmanager" }
+hilt-work = { group = "androidx.hilt", name = "hilt-work", version.ref = "hilt-work" }
+hilt-work-compiler = { group = "androidx.hilt", name = "hilt-compiler", version.ref = "hilt-work" }
+gson = { group = "com.google.code.gson", name = "gson", version.ref = "gson" }
+core-ktx = { group = "androidx.test", name = "core-ktx", version.ref = "coreKtxVersion" }
 
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }
@@ -57,4 +87,6 @@ kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }
 kotlin-jvm = { id = "org.jetbrains.kotlin.jvm", version.ref = "kotlin" }
 hilt = { id = "com.google.dagger.hilt.android", version.ref = "hilt" }
 ksp = { id = "com.google.devtools.ksp", version.ref = "ksp" }
+detekt = { id = "io.gitlab.arturbosch.detekt", version.ref = "detekt" }
+kotlin-serialization = { id = "org.jetbrains.kotlin.plugin.serialization", version.ref = "kotlin-serialization" }
 
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..8bdaf60
Binary files /dev/null and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/settings.gradle.kts b/settings.gradle.kts
index e1ea7e3..5691d6c 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -25,11 +25,10 @@ dependencyResolutionManagement {
 rootProject.name = "CatalogApp"
 include(":app")
 include(":core:network")
-include(":core:database")
-include(":core:designsystem")
 include(":core:common")
-include(":data:product")
 include(":domain:product")
+include(":data:product")
+include(":core:designsystem")
 include(":feature:catalog")
 include(":feature:detail")
 include(":feature:search")