[tibastral2]

I don't recommend css. Css is BLOATED. And tailwind makes it a little less bloated, but it's still not strongly typed, and not very re-usable, especially in code.

But your approach is from the past man, really... .btn is not reusable among pages / projects / etc. => it's always different, and when you understand that specificity wars is the main problem of css, you will not want to use your idea again.

It LOOKS cool to have a <button class="btn"> inside your html. because it's more readable. But it's NOT explicit. You fragment truth into different pieces. and it makes it IMPOSSIBLE to test things in isolation.

One last thing. Using all the "last features" of css is just putting you in a place where you depend on the browser carriers to handle things for you when I prefer personnaly to rely on myself and my craft. But that's a personal one ;)