CSS on its own can be fun, but stylesheets are getting larger, more complex, and harder to maintain. This is where a preprocessor can help. Sass lets you use features that don't exist in CSS yet like variables, nesting, mixins, inheritance and other nifty goodies that make writing CSS fun again.
that's from the Sass website, while I agree that may have been true 10 years ago, CSS has come a long way since then :) i think most of Sass's features (as listed here) are all things CSS3 has since taken care of. so, without further ado, my case:
SCSS (example from their website)