udate index.css

web/css/index.css

@@ -36,14 +36,14 @@
 
 body {
     font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
-    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+    background: var(--bg-primary);
     height: 100vh;
     overflow: hidden;
     transition: background 0.3s ease;
 }
 
 [data-theme="dark"] body {
-    background: linear-gradient(135deg, #2c3e50 0%, #3498db 100%);
+    background: var(--bg-primary);
 }
 
 /* Auth Container */