diff --git a/Web/css/modern.css b/Web/css/modern.css
index 2164d0d..fa4e0ba 100644
--- a/Web/css/modern.css
+++ b/Web/css/modern.css
@@ -8,7 +8,7 @@
 }
 
 body {
-    background: linear-gradient(135deg, var(--bg-dark), var(--bg-dark2));
+    background: linear-gradient(135deg, var(--bg-dark), var(--primary-blue));
     color: var(--text-light);
     min-height: 100vh;
     font-family: system-ui, sans-serif;
@@ -50,6 +50,16 @@ a:hover, .btn:hover, .nav-link:hover {
     border-color: rgba(255,255,255,0.1) !important;
 }
 
+/* Main window styling (window within window) */
+.custom-container.dark-box {
+    margin: 2rem;
+    background: linear-gradient(135deg, rgba(0,0,0,0.45), rgba(59,130,246,0.2));
+    border: 2px solid var(--primary-blue);
+    border-radius: var(--border-radius);
+    padding: 1rem;
+    backdrop-filter: blur(6px);
+}
+
 /* Light mode overrides */
 html[data-bs-theme="light"] {
     --bg-light: #f8f9fa;