Reduce border-radius from 10px to 4px for subtler corners

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: etzm

assets/css/style.css

@@ -18,7 +18,7 @@
   --font-mono: "DM Mono", monospace;
   --max-width: 1100px;
   --nav-height: 64px;
-  --radius: 10px;
+  --radius: 4px;
   --shadow: 0 2px 16px rgba(123, 45, 142, 0.08);
 }