Enhance WordPress Site Performance & Responsive Design

WordPress experience required. The site is currently offline (taken off hosting intentionally) — all work is done locally on a copy I'll send you (files + DB dump). Deploy via LocalWP, XAMPP, MAMP or Docker, your choice... (Budget: €50000 - €100000 EUR, Jobs: CSS, Docker, Documentation, HTML, PHP, Web Development, Website Optimization, WordPress)