google/WebFundamentals ? reverse-engineered prompt

Build me a clean, working version of the old Google Web Fundamentals site so it feels like a polished documentation hub for web best practices, HTML, CSS, JavaScript, mobile web, and progressive web apps.

I want a homepage, topic pages, and article pages that are easy to browse, with a simple navigation layout, responsive design, and readable typography. It should be able to run locally for development, generate the pages from the existing content files, and handle markdown or HTML articles without breaking. Please keep the styling modern but close to a developer documentation site, and make sure the content structure is easy to update later.

If anything is unclear from the existing files, inspect the repo and figure out the simplest way to get it working, and look up current docs online if you need to.