Fix UI

Author: zxdong262

src/views/parts/download.pug

@@ -1,4 +1,3 @@
-
 // Main download section with OS detection
 .download-main.mg3t
   .download-hero
@@ -202,18 +201,30 @@ script.
   document.addEventListener('DOMContentLoaded', function() {
     const tabButtons = document.querySelectorAll('.tab-btn');
     const tabPanels = document.querySelectorAll('.tab-panel');
-    
+
+    function activateTab(tabName) {
+      tabButtons.forEach(btn => {
+        const isTarget = btn.getAttribute('data-tab') === tabName;
+        btn.classList.toggle('active', isTarget);
+      });
+      tabPanels.forEach(panel => {
+        const isTarget = panel.getAttribute('data-tab') === tabName;
+        panel.classList.toggle('active', isTarget);
+      });
+    }
+
+    // Set default tab based on detected OS
+    try {
+      const os = typeof detectOS === 'function' ? detectOS() : 'windows';
+      activateTab(os);
+    } catch (e) {
+      activateTab('windows');
+    }
+
     tabButtons.forEach(button => {
       button.addEventListener('click', function() {
         const targetTab = this.getAttribute('data-tab');
-        
-        // Remove active class from all buttons and panels
-        tabButtons.forEach(btn => btn.classList.remove('active'));
-        tabPanels.forEach(panel => panel.classList.remove('active'));
-        
-        // Add active class to clicked button and corresponding panel
-        this.classList.add('active');
-        document.querySelector(`.tab-panel[data-tab="${targetTab}"]`).classList.add('active');
+        activateTab(targetTab);
       });
     });
   });