Website CSS/JS Visual Revamp

I need the public-facing look of my current site to mirror a demo design, and I can inject custom code directly from the CMS. No database work, template restructuring, or plug-in installations are required—just clean, modular front-end tweaks... (Budget: $250 - $750 USD, Jobs: CSS, Frontend Development, HTML, JavaScript, jQuery, PHP, Web Development, Website Optimization)