Fix accessibility violations: color contrast, aside nesting

- Improve text contrast from #666/#888/#999 to #555/#6b6b6b across site (WCAG AA)
- Fix aside nesting in all 10 blog articles (aside→div in related-articles)
- Fix aside nesting in quote sidebar
- Update CRO enhancement CSS/JS inline colors

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

blog/articles/contract-review-automation-law-firms.php

@@ -58,14 +58,14 @@ include($_SERVER['DOCUMENT_ROOT'] . '/includes/nav.php');
             <p>If your firm reviews significant volumes of any contract type and you want to understand what an automated review system would look like for your practice, we are happy to walk through the options.</p>
 
         </div>
-            <aside class="related-articles">
+            <div class="related-articles">
                 <h2>Related Articles</h2>
                 <ul>
                     <li><a href="/blog/articles/due-diligence-automation-law-firms">How Law Firms Can Automate Due Diligence Document Review</a></li>
                     <li><a href="/blog/articles/ma-due-diligence-automation-corporate-law">M&amp;A Due Diligence Automation for Corporate Law Firms</a></li>
                     <li><a href="/blog/articles/cost-of-manual-data-work-professional-services">The Real Cost of Manual Data Work</a></li>
                 </ul>
-            </aside>
+            </div>
         <footer class="article-footer">
             <p>Written by <strong>UK AI Automation</strong> — <a href="/quote">Get a Quote</a></p>
         </footer>