diff --git a/index.html b/index.html
index a36c4dd..e3811ff 100644
--- a/index.html
+++ b/index.html
@@ -18,6 +18,7 @@
         <a href="#signal">Signal</a>
         <a href="#drift">Drift</a>
         <a href="#arrival">Arrival</a>
+        <a href="#fallback">Fallback</a>
       </nav>
     </header>
 
@@ -56,6 +57,17 @@ <h2>도착</h2>
           <p>중앙 maintainer bot이 다음 장면, 접근성, fallback 개선을 작은 PR로 제안합니다.</p>
         </div>
       </section>
+
+      <section id="fallback" class="chapter scene scene-d">
+        <div class="scene-card">
+          <span>04</span>
+          <h2>대체 항로</h2>
+          <p>
+            모션이 꺼져도 모든 장면은 순서대로 읽히며, no-JS 검증이 스토리의 기본 항로를
+            지킵니다.
+          </p>
+        </div>
+      </section>
     </main>
   </body>
 </html>
diff --git a/styles.css b/styles.css
index 72ef5af..17648f5 100644
--- a/styles.css
+++ b/styles.css
@@ -189,6 +189,15 @@
     --scene-bg: #fffdf7;
   }
 
+  .scene-d {
+    --scene-accent: 52 121 96;
+    --scene-glow-position: 30% 68%;
+    --scene-glow-alpha: 11%;
+    --scene-sweep-alpha: 8%;
+    --scene-sweep-stop: 56%;
+    --scene-bg: #f7fff9;
+  }
+
   .scene-card {
     --scroll-animation: reveal-card;
     --scroll-animation-range: entry 8% cover 42%;