Mobile Responsive Website Upgrade

My current website works fine on desktop, but falls short on phones and tablets, so I need a developer who can focus on giving it true mobile responsiveness. The aim is to raise the overall user experience—smooth layouts, touch-friendly elements and fast, fluid scrolling on every modern device... (Budget: $15 - $25 USD, Jobs: Bootstrap, CSS, Frontend Development, HTML, HTML5, JavaScript, Mobile App Development, Web Development)