Take a look at Pinegrow [0] (I'm the author). It is a desktop app that lets you visually work with standard HTML & CSS files and supports frameworks such as Bootstrap, Tailwind CSS or just plain old CSS. There are also more advanced features, for example live SASS compilation, components, interactions and even exporting WordPress themes and blocks.
Any plan to compile this to webassembly and make it run in the browser? Webflow is killing it. I had no idea there were other options.
To be clear, I... don't even know why I want that? Desktop software runs faster than webapps do. But for some reason I feel like people these days simply prefer to not download stuff. Weird.
Tried Pinegrow(and similar UI tools), didnt like it. They expect you to still know all the low level details, at which point you might as well write straigth css
[0] https://pinegrow.com