Website Functionality & Navigation Overhaul Phase 2

My current site works, but only just—I’m now ready to tighten up the codebase and make the user journey smoother. The priority is functionality: pages should load snappily, interactive elements must behave... (Budget: £100 - £1000 GBP, Jobs: CSS, Frontend Development, HTML, PHP, User Experience Research, Web Development, Website Design, Website Optimization)