Messages column: account for body padding-bottom in sticky height

static/index.html

@@ -205,10 +205,12 @@
   }
 
   /* --- Messages (right column) --- */
-  /* Sticky chat that fills the available viewport height. */
+  /* Sticky chat that fills the available viewport height.
+     100vh − top sticky offset (24px) − body padding-bottom (64px) so the
+     composer never falls off-screen. */
   .messages-col {
     position: sticky; top: 24px;
-    height: calc(100vh - 48px);
+    height: calc(100vh - 88px);
     display: flex; flex-direction: column;
   }
   .messages-col .section-title { flex: 0 0 auto; }