One-Page Site Refinement

I already have a live, single-page website that acts purely as an informational hub. All of the content is in place—mainly text and images—but the page needs a round of professional polish so it feels tighter, loads faster, and looks consistent on every screen size... (Budget: $250 - $750 USD, Jobs: CSS, HTML, JavaScript, PHP, Typography, Web Design, Web Development, Website Design, Website Optimization, WordPress)