feat(ui): add smooth collapse animation for subscriptions list

Replace display toggle with CSS transitions for subscriptions list collapse

js/script.js

@@ -778,12 +778,12 @@ function bindEvents() { // Bind events to the DOM elements
         const subscriptionsList = document.querySelector('.subscriptions-list');
         const chevron = subscriptionTitle.querySelector('i');
         
-        if (subscriptionsList.style.display === 'none') {
-            subscriptionsList.style.display = 'block';
-            chevron.style.transform = 'rotate(0deg)';
-        } else {
-            subscriptionsList.style.display = 'none';
+        subscriptionsList.classList.toggle('collapsed');
+        
+        if (subscriptionsList.classList.contains('collapsed')) {
             chevron.style.transform = 'rotate(-90deg)';
+        } else {
+            chevron.style.transform = 'rotate(0deg)';
         }
     });
 }