Maybe you think moving from static CSS files to (mostly-static) CSS preprocessing was a huge revolution for your app's styling. I've got news for you. You're still stuck in quicksand.
If you want more out of your CSS, it should be dynamically templated, not just build-processed. Render the CSS on-the-fly, responding to run-time conditions, either on the server or in the browser. And that's just the beginning. Imagine modifying CSS structure and rule-relationships in process, re-compiling then re-rendering? Yep.
Are you still excited because your CSS automatically re-compiles on save? CSS.past. Open your eyes to the next big things in CSS. You don't need more fancy features and coding constructs IN your CSS file, you just need super-charged CSS tools. Welcome to CSS templating.
We haven't scratched the surface of what CSS can do for us yet. It's time we get scratching.