Fix contact form styles + narrow screen nav clipping

- Alias .form-group to .form-field in main.css so contact form inputs get full styling
- Hide header Get Estimate btn on <=480px (mobile drawer has CTA, prevents logo+btn+hamburger overflow)
- Tighten header-inner gap to space-4 on <=480px
- Drop redundant btn-sm padding override from 360px rule (btn now hidden at that width)

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

assets/css/components.css

@@ -1479,12 +1479,14 @@ details.faq-item p {
   .header-logo-sub { display: none; }
 }
 
-/* Ultra-narrow phones (iPhone SE portrait, 320px) : tighten header */
+/* Narrow phones: drop Get Estimate btn, hamburger + logo only */
+@media (max-width: 480px) {
+  .header-cta .btn--sm { display: none; }
+  .header-inner { gap: var(--space-4); }
+}
+
+/* Ultra-narrow phones (320px) */
 @media (max-width: 360px) {
-  .header-cta .btn--sm {
-    padding-inline: 0.75rem;
-    font-size: 0.75rem;
-  }
   .header-logo img { height: 36px !important; }
   .container { padding-inline: 0.875rem; }
 }