Website Fixes & Feature Enhancements

My website is already live on a custom HTML / CSS / JS stack, but several areas need attention. Some links land on 404s, a few pages have layout glitches, and certain interactive elements no longer behave as expected... (Budget: ₹600 - ₹1500 INR, Jobs: CSS, Frontend Development, HTML, JavaScript, PHP, React.js, React.js Framework, Web Design, Web Development, Website Optimization)