diff --git a/frontend/src/pages/ChatPage.tsx b/frontend/src/pages/ChatPage.tsx
index 8c8a7d8..22e2d6c 100644
--- a/frontend/src/pages/ChatPage.tsx
+++ b/frontend/src/pages/ChatPage.tsx
@@ -80,6 +80,14 @@ const ChatPage: React.FC = () => {
   const typingTimeoutRef = useRef<NodeJS.Timeout | null>(null);
   const fileInputRef = useRef<HTMLInputElement>(null);
 
+  // Prevent body scroll on mobile so navbar and bottom tabs stay fixed
+  useEffect(() => {
+    document.body.style.overflow = 'hidden';
+    return () => {
+      document.body.style.overflow = '';
+    };
+  }, []);
+
   const loadMessages = useCallback(async () => {
     try {
       const res = await getMessages(mode);