Fix large font on chapter links in other sections

Scope the 1.8rem font-size rule to only the .chapters-section
so parenthetical chapter references in other sections don't
get enlarged.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

kjvstudy_org/templates/book.html

@@ -4,7 +4,7 @@
 
 {% block head %}
 <style>
-section h2 + p a {
+.chapters-section h2 + p a {
     font-size: 1.8rem;
     font-weight: 500;
 }
@@ -331,7 +331,7 @@ document.addEventListener('DOMContentLoaded', function() {
 </div>
 {% endif %}
 
-<section>
+<section class="chapters-section">
     <h2>Chapters</h2>
     <p>
         <label for="mn-popular" class="margin-toggle">⊕</label>