My store, chaiaofficial.com, is built on Shopify and needs three quick but crucial improvements. 1. Homepage video The embedded hero video never loads—it just sits on a blank thumbnail. I need the media file or embed replaced or re-configured so it autoplays (muted) on desktop and gracefully degrades to a static image on slower connections. Please keep page-speed and Core Web Vitals in mind while you work—lazy-loading or a lightweight MP4/WebM swap is fine as long as the result is reliable. 2. Mobile responsiveness The site does open on phones, yet most elements shift, overlap, or disappear. I want a clean, touch-friendly layout that respects the current branding. Tweak Liquid templates, CSS or theme settings so product grids, menus, buttons and the checkout flow render perfectly on common iOS and Android viewports. 3. Clothing size options Products need size selections (XS–XL for tops, 24–32 for bottoms). Create the necessary product options/variants and ensure the size chart link appears on each product page. No bulk-editing apps—do it natively or via Shopify CSV so inventory tracking still works. Acceptance criteria • Video loads and plays on desktop; static fallback shows on unsupported devices. • Site passes Google’s Mobile-Friendly Test with no overlapping content warnings. • All apparel products display clear, selectable clothing sizes and update price/stock correctly. You’ll work in a collaborator account; please outline any theme code changes so I can track future updates. Looking for someone who can wrap this up within a day or two using standard Shopify tools, Liquid, CSS, and a pinch of JavaScript if needed.