diff --git a/DECISIONS.md b/DECISIONS.md
index 7d78665..9b84911 100644
--- a/DECISIONS.md
+++ b/DECISIONS.md
@@ -118,3 +118,9 @@ Implementation details:
 - The round resets when all distinct user IDs present in the topic's entries have been picked.
 - Toggling fair mode off clears the tracking array.
 - State is persisted in localStorage alongside existing topic data.
+
+## Responsive Add-Entry / Add-User / Add-Topic Forms
+
+_Date: 2026-05-07_
+
+Made the add-entry form (`.add-entry-form`) and the sidebar input rows (`.input-row`) wrap on narrow viewports so the **Add** button is never pushed off-screen on mobile. Specifically, `flex-wrap: wrap` is enabled on both rows; `.input-field` uses `flex: 1 1 120px` with `min-width: 0` so inputs can shrink and reflow instead of overflowing; and on viewports ≤ 480px the entry form's submit button stretches to full width on its own row for an easier mobile tap target. Rationale: the previous fixed single-row flex layout assumed enough horizontal space for input + user-select + button, which fails on phone-width screens. Wrapping is preferred over horizontal scrolling for accessibility and usability.
diff --git a/css/styles.css b/css/styles.css
index 556b93f..bc71262 100644
--- a/css/styles.css
+++ b/css/styles.css
@@ -359,11 +359,13 @@ body {
 
 .input-row {
   display: flex;
+  flex-wrap: wrap;
   gap: 8px;
 }
 
 .input-field {
-  flex: 1;
+  flex: 1 1 120px;
+  min-width: 0;
   background: var(--clr-input-bg);
   border: 2px solid var(--clr-border);
   border-radius: var(--radius-sm);
@@ -535,9 +537,14 @@ body {
 /* ---------- Add Entry Form ---------- */
 .add-entry-form {
   display: flex;
+  flex-wrap: wrap;
   gap: 8px;
 }
 
+.add-entry-form .btn {
+  flex: 0 0 auto;
+}
+
 /* ---------- Entries List ---------- */
 .entries-list {
   display: flex;
@@ -888,4 +895,8 @@ body {
   .topic-item {
     flex-shrink: 0;
   }
+
+  .add-entry-form .btn[type="submit"] {
+    flex: 1 1 100%;
+  }
 }