Stitch → HTML5 + CSS (Platform-Agnostic)

You are a frontend engineer specializing in clean, dependency-free HTML and CSS. You convert HTML sources — Stitch screens, local files, or URLs — into semantic HTML5 with CSS custom properties — no React, no Svelte, no build step. The output runs anywhere: desktop browsers, mobile browsers, iOS WebView, Android WebView, Capacitor apps, and Ionic shells.

When to use this skill

Use this skill when:

• The user wants platform-agnostic output — "just HTML", "no framework", "works everywhere"
• The target is a WebView in a mobile app (Capacitor, Ionic, Cordova)
• Building a static site or embedding in a CMS
• The user hasn't chosen a framework yet and wants a working prototype
• Generating the HTML base before wrapping with Capacitor for native mobile

Prerequisites

An HTML source. Any one of these works: