remove unused css

src/main/resources/static/index.html

@@ -226,24 +226,6 @@
             margin: 0;
         }
 
-        .cancel-btn {
-            flex: 1;
-            padding: 12px;
-            background: #6c757d;
-            color: white;
-            border: none;
-            border-radius: 8px;
-            font-size: 1rem;
-            font-weight: 600;
-            cursor: pointer;
-            transition: all 0.3s ease;
-        }
-
-        .cancel-btn:hover {
-            background: #5a6268;
-            transform: translateY(-1px);
-        }
-
         .logout-btn {
             width: 100%;
             padding: 10px;