Modern Kurti Store Website help to setup payment gateway

I’m ready to refresh my online kurti shop with a sleek, modern-minimal interface that feels light, intuitive, and mobile-first. The build revolves around three core screens: All pages ia already setup. i need help in payment gateway Clean typography, plenty of white space, and a muted color palette that lets fabric patterns stand out are key. Please implement responsive HTML/CSS/JS, or propose a lightweight CMS (Shopify, WooCommerce, or similar) if you think it will speed up product updates. Load time under three seconds and basic SEO tags are part of the acceptance criteria. Hand-off should include all source files plus a quick walk-through of how I can update images, prices, and descriptions on my own.