fix responsive

static/index.html

@@ -142,8 +142,8 @@ body { z-index:1; }
 .rec-dot { width:7px; height:7px; border-radius:50%; background:var(--accent-red); animation:blink-dot 0.8s ease-in-out infinite alternate; }
 @keyframes blink-dot { from{opacity:1} to{opacity:0.2} }
 @media (max-width: 768px) {
-  #sidebar { display:none; }
-  #chat-area { border-right:none; }
+  #sidebar { display:none !important; width:0 !important; min-width:0 !important; padding:0 !important; border:none !important; overflow:hidden !important; }
+  #chat-area { border-right:none; flex:1; }
   #messages { padding:16px; }
   #input-area { padding:10px 12px; }
   .msg { max-width:92%; }