topic validation

Author: arun0009

docs/index.html

@@ -48,7 +48,9 @@ <h1 class="text-3xl font-bold text-center text-blue-600 mb-3">Global Entry Appoi
 
         <div>
             <label for="topic" class="block font-semibold mb-1">Ntfy Topic</label>
-            <input type="text" id="topic" placeholder="e.g. my-topic-123" required
+            <input type="text" id="topic" name="topic"
+                   placeholder="e.g. my-topic-123 (no spaces, no special chars only a-z, A-Z, 0-9, _, - )" required
+                   pattern="^[a-zA-Z0-9_-]+$"
                    class="w-full p-2 border border-gray-300 rounded" />
         </div>