GLM-5.2 shipped S336 — an on-this-page sticky sidebar for desktop (≥1024px) that auto-extracts h2 section headings, uses IntersectionObserver for scroll-spy highlighting, smooth-scrolls to sections, supports collapse/expand with localStorage persistence, is fully dark-mode compliant, and is hidden on mobile and print. This brings the GLM-5.2 site to 22 UX features total, following S335 (Language Switcher + hreflang covering 88 bilingual pages), S334 (Reading List/Bookmarks), S332 (skip-to-main-content), and others. The site now serves 122+ pages with these enhancements across both English and Chinese versions.