Improve header ad responsiveness and appearance on all devices

Update HeaderAd.tsx to use responsive ad attributes, set width to 100% with a max-width of 728px, and add data-ad-format="auto" and data-full-width-responsive="true" for better ad rendering.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 45a1dcfc-f8a2-475a-a6b9-96fbb841dc27
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/60d372ff-2c10-46c7-b01b-10c3435136b0/45a1dcfc-f8a2-475a-a6b9-96fbb841dc27/C7qkn51

client/src/components/HeaderAd.tsx

@@ -21,13 +21,20 @@ export default function HeaderAd() {
   }, []);
 
   return (
-    <div className="w-full flex justify-center py-1 bg-bunny-dark" ref={adRef}>
-      {/* Fixed Header/Footer Ad */}
+    <div className="w-full flex justify-center py-1 px-2 bg-bunny-dark" ref={adRef}>
+      {/* Responsive Header Ad */}
       <ins 
         className="adsbygoogle"
-        style={{ display: 'inline-block', width: '728px', height: '90px' }}
+        style={{ 
+          display: 'inline-block', 
+          width: '100%', 
+          maxWidth: '728px',
+          height: '90px'
+        }}
         data-ad-client="ca-pub-4465464714854276"
         data-ad-slot="7241323742"
+        data-ad-format="auto"
+        data-full-width-responsive="true"
       />
     </div>
   );