Reasonable System for CSS Stylesheet Structure… a bit of a mouthful but some useful tips like
Use classnames whenever possible. Tag selectors are fine, but they may come at a small performance penalty and may not be as descriptive.
I’m sure one of the linters I use complains when I do this anyway.
I definitely buy into splitting css (and development in general) into components and then using build tools to bundle and minify the files, rather than trying to put them all in one huge file. The only problem with this approach is they need to be easy to find, which can be tricky when you start having a lot of components.