diff --git a/chatserver/templates/index.html b/chatserver/templates/index.html
index 86ae479..46a4d96 100644
--- a/chatserver/templates/index.html
+++ b/chatserver/templates/index.html
@@ -106,7 +106,7 @@
         }
     </style>
 </head>
-<body class="light-mode">
+<body class="dark-mode">
     <!-- Top Bar -->
     <div id="topBar">
         <span id="userInfo">Username: <strong id="currentUsername"></strong> | Chat Room: <strong id="currentChatRoom"></strong></span>
@@ -127,9 +127,14 @@
     </div>
 
     <script>
-        // Ask the user for the server URL
-        const serverUrl = prompt("Enter the WebSocket server URL (e.g., http://localhost:5000):") || 'http://localhost:5000';
-        const socket = io(serverUrl); // Connect to the WebSocket server
+        // Determine the default server URL based on the web client's host
+        const defaultServerUrl = `${window.location.protocol}//${window.location.hostname}:5000`;
+
+        // Ask the user for the server URL, defaulting to the web client's host
+        const serverUrl = prompt(`Enter the WebSocket server URL (default: ${defaultServerUrl}):`) || defaultServerUrl;
+
+        // Connect to the WebSocket server
+        const socket = io(serverUrl);
 
         const chatDiv = document.getElementById('chat');
         const messageInput = document.getElementById('message');
@@ -212,11 +217,17 @@
             if (body.classList.contains('light-mode')) {
                 body.classList.remove('light-mode');
                 body.classList.add('dark-mode');
+                localStorage.setItem('theme', 'dark-mode'); // Save preference
             } else {
                 body.classList.remove('dark-mode');
                 body.classList.add('light-mode');
+                localStorage.setItem('theme', 'light-mode'); // Save preference
             }
         }
+
+        // Apply saved theme on page load
+        const savedTheme = localStorage.getItem('theme') || 'dark-mode'; // Default to dark mode
+        document.body.classList.add(savedTheme);
     </script>
 </body>
 </html>
\ No newline at end of file