Fix mobile top spacing (double header offset) + CTA/newsletter gap

On mobile, body already has padding-top:60px to clear the fixed header, but
every page ALSO added its own clearance — doubling it and leaving a ~60px
white gap under the menu (content sat too low). Trimmed each page's mobile
top offset so it relies on the body padding (matching .article-page, which
was already correct): page-content, support/hub/legal pages, and the
news-hub / news-article / blog / member heroes. Content now sits ~32-42px
under the header.

Also add a 32px top gap to .newsletter-cta on mobile so it no longer
touches the CTA/content above it.

CSS only.

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

css/pages/_blog.css

@@ -193,7 +193,7 @@
     .blog-feat--lg .blog-feat-thumb { min-height: 200px; }
 }
 @media (max-width: 768px) {
-    .blog-hero { padding: 92px 20px 32px; }
+    .blog-hero { padding: 32px 20px 32px; } /* body offsets the fixed header on mobile */
     .blog-hero h1 { font-size: 30px; }
     .blog-grid { columns: 1; }
 }