Yanling Wang modernized the layout system in the mozilla/gecko-dev repository by migrating masonry layouts from deprecated masonry-* CSS properties to a CSS Grid-based approach. This refactor improved layout consistency, responsiveness, and maintainability for components using masonry patterns. Yanling utilized CSS, HTML, and JavaScript to align the codebase with grid-based templating and sizing, removing outdated properties and redundant test files to reduce technical debt. The work focused on future-proofing the layout architecture, enabling easier scalability and cleaner code. Over the month, Yanling’s contributions demonstrated a methodical approach to web platform testing and standards-driven front-end engineering practices.