Add timer

index.html

@@ -18,6 +18,13 @@
         <div id="topicsContainer" class="space-y-3 sm:space-y-4">
             <!-- Topics will be inserted here -->
         </div>
+
+        <div class="mt-6 text-center">
+            <button id="timerBtn" class="bg-green-600 hover:bg-green-700 text-white font-semibold py-2 sm:py-3 px-4 sm:px-6 rounded-lg shadow-lg transition duration-300 ease-in-out transform hover:scale-105">
+                Start Timer
+            </button>
+            <div id="timerDisplay" class="text-4xl sm:text-5xl font-bold text-blue-800 mt-4"></div>
+        </div>
     </div>
 
     <script src="js/index.js"></script>