googlecodelabs/tools ? reverse-engineered prompt

Build me a codelab authoring and publishing tool that lets me create interactive tutorials from either a Google Doc or a Markdown file, then export them into a polished web version and markdown version.

I want a simple way to preview the codelab locally while I am editing, then serve it as a static site that I can host anywhere. It should support the usual codelab style with step by step instructions, code blocks, screenshots, and a nice responsive layout that works on desktop and mobile. If possible, also include a landing page or summary page for a set of codelabs, so I can publish multiple tutorials in one place.

Please make it easy to run locally, and include clear instructions for building, previewing, and publishing. If you need to check current docs or best practices, go ahead and look them up online.