HTML is made to be flexible by using CSS, LaTeX is a typesetting program. It sets the whole document to look nice in one specific view, which is the final PDF. Or mre precisely, LaTeX works best for printed media
There are efforts for web maths, which would close the gap considerably for rendering science articles.
Most of the other LaTeX features can be achieved with HTML, CSS and maybe JS. Or even Markdown + preprocessor.
it can be achieved, but at what cost? you need to waste time with css and js to get something latex gets you out of the box.
The question was is there something like latex for frontend, and is the "monospace web" it?
"html does the thing" can technically be a true answer, if you completely ignore any contextual understanding.
I'm looking for a simpler solution, not one that would waste more time.
You are asking for a responsive weblayout, which excludes any format that LaTeX outputs.
Latex is a typesetting engine that does the job before presenting anything and not while presenting it. Its layouts are not responsive by design.
So your question if there is something like LaTeX for frontend is just misplaced, because the working method of LaTex does not fit into a responsive weblayout frontend.
What LaTeX features do you want in a frontend? How do you want to write code and how do you want the layout to happen?
What you describe sounds more like static site generation with math handling and perhaps references. There are markdown extensions that can handle such things. For rendering there is e.g. https://www.mathjax.org/
This is a bit like insisting on using latex without ever touching packages, and then asking for the functionality of packages anyway. At least for the CSS part.
