Improve deployment safety and chat reliability

frontend/css/style.css

@@ -398,6 +398,8 @@ textarea {
   display: flex;
   flex-direction: column;
   height: calc(100vh - 57px);
+  /* dvh follows the mobile toolbar as it collapses; vh above is the fallback */
+  height: calc(100dvh - 57px);
 }
 
 .chat-messages {
@@ -1040,6 +1042,13 @@ tr:hover td {
     padding: 12px 16px;
   }
 
+  /* iOS Safari zooms the whole page in when a focused field is under 16px */
+  input,
+  select,
+  textarea {
+    font-size: 16px;
+  }
+
   .message {
     max-width: 88%;
   }