jnsahaj/tweakcn ? reverse-engineered prompt

Build me a website that works as a visual theme editor for shadcn/ui components. I've noticed a lot of sites using shadcn/ui look the same, so this tool should help developers create a unique style visually.

The app should have a main preview area that displays all the common components like buttons, cards, inputs, and alerts. On the side, there should be a control panel with sliders and color pickers to adjust the theme. Users should be able to change things like primary colors, border radius, and fonts, and see the components in the preview update in real-time.

It should also come with a few beautiful starter themes or presets that people can choose from and then customize further to make their own. The goal is to make it easy to create a distinct visual identity for a project. Let's build this using Next.js and Tailwind CSS.