Fix mobile content margins

Reduce left/right padding on screens under 640px to prevent content from being squished. Body and content padding reduced from 20px to 8px per side, and info section viewport-relative padding reduced from 10vw to 4vw.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Author: wow-miley

src/commonMain/resources/index.css

@@ -687,6 +687,21 @@ button {
     }
 }
 
+@media (max-width: 640px) {
+    html,
+    body {
+        padding: 0 8px;
+    }
+
+    .content {
+        padding: 0 8px;
+    }
+
+    .info {
+        padding: 24px 4vw;
+    }
+}
+
 @media (max-width: 430px) {
     .footer {
         height: 50px;