The Issue with Preprocessing CSS Custom Properties

CSS has Custom Properties now. We’ve written about them a bunch lately. Browser support is good, but of course, old non-evergreen browsers like Internet Explorer don’t have them and never will. I can see the appeal of authoring with “future CSS", and letting a preprocessor backport it to CSS that is compatible with older browsers. Babel for CSS! Why not?!
It makes me nervous though – because it’s only some use cases of Custom Properties that you can preprocess. …

The Issue with Preprocessing CSS Custom Properties is a post from CSS-Tricks

Link: https://css-tricks.com/issue-preprocessing-css-custom-properties/