nuxt/ui — reverse-engineered prompt

Build me a polished Vue and Nuxt UI library called Nuxt UI. I want developers to be able to install it, add it to a Nuxt app or a plain Vue app, import the CSS, and immediately use beautiful accessible components styled with Tailwind. Make it feel modern, fast, themeable, and easy to customize, with sensible defaults and dark mode friendly design.

Include a simple docs site or playground that shows how to install it, how to use the main components, and a few starter examples like a landing page, docs page, dashboard, chat, portfolio, changelog, and editor concept. Please include tests and basic contributor notes so someone can keep improving components safely.

Use current Nuxt UI docs online if you need to check patterns. Keep the code organized as a reusable package, not just a one off demo app, and make sure it can be published and used by other projects.