website design – Looking for HTML and CSS generating software

Apologies if this isn’t the right SE forum for my question, but it doesn’t seem to fit anywhere.

I’m creating a web app and am trying to find a drag-and-drop editor that generates HTML and CSS so I can copy the code, which would save a lot of time. I had a look round google and there seem to be a lot of codeless website builders, and a lot of web design and mockup tools, but nothing in between.

I need something that enables creating pages with HTML, importing CSS libraries (preferably Bootstrap), and copying the generated code to be included in my source code, no javascript or backend functionality needed. If anyone’s come across software like this I’d love to know.

(I know that SE isn’t the place for asking opinions on software, but this is a question on whether any software actually exists rather than if it’s good.)