Someone posted here, thanks for that!! It immediately reminded me of HAML: https://harcstack.org/

I like HAML a lot, it was the most pleasant to develop with. And it shares a lot in common with Stylus. They both shared things in common.

NO NEED FOR: Curly braces, parentheses and semicolons. The cool thing, it was all optional and I wasn't forced to make use of all shortcuts!

I developed my own CSS Framework in 2003, shared with some UX guy at Yahoo, who incorporated it into YUI mostly as is, after I waived all rights. Most of that became internet standard. Later I had my own PHP based CSS scaffolding framework in 2005 that could also generate grids (before flex-box). SCASS/LESS was really similar to my framework, when it came out.

But I disliked it, it just looked like PHP mixed with CSS. I thought why accept the ugly syntax, despite a compiler being available?

The best ever existed is: HAML + Stylus + (HARC?)

See the beauty of it: https://stylus-lang.com/docs/selectors.html

Now compare with HAML https://haml.info/

I think https://harcstack.org/ makes a good successor.

Svelte already has a Pug preprocessor :)

I used to use it years ago. So much nicer than HTML.

vue allows other languages in .vue files for both css & html similar to js