style(brand): unify orange to #FA7850 + yellow token; fix tablet header gap

- Brand orange is now the official #FA7850 everywhere: folded the stray
  oranges (#F2762E, #E8833A, #ff6b2c) into it and kept a single darker shade
  (#E85D2A) for gradient depth + button hover. Added the official brand
  --yellow (#FFE16E) token.
- Tablet header gap (769-1024px): the fixed header shrinks 80->60px there but
  first-section paddings kept their 80px clearance; pull the first section up
  by the 20px delta in that range only (phones untouched). Verified on
  interior pages and the full-bleed homepage hero — gap now matches desktop,
  no overlap.
- Re-stamped cache-bust (v=f95de694).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

404.html

@@ -25,7 +25,7 @@
     <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap" rel="stylesheet">
     <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css" crossorigin="anonymous" referrerpolicy="no-referrer">
-    <link rel="stylesheet" href="/css/main.css?v=1f64b22f">
+    <link rel="stylesheet" href="/css/main.css?v=f95de694">
 
     <link rel="icon" type="image/png" href="/favicon-96x96.png" sizes="96x96">
     <link rel="icon" type="image/svg+xml" href="/favicon.svg">
@@ -70,7 +70,7 @@
             </p>
         </div>
     </main>
-<link rel="stylesheet" href="/assistant.css?v=1f64b22f">
-<script src="/assistant.js?v=1f64b22f" defer></script>
+<link rel="stylesheet" href="/assistant.css?v=f95de694">
+<script src="/assistant.js?v=f95de694" defer></script>
 </body>
 </html>