CSS is great and can be really powerful but it’s lacking some pretty significant features that are needed to keep it moving forward. Things like variables, reusability, math calculations, nesting, etc. These things are achieved with Sass. We chose to use Sass over Less primarily because of the syntax differences but both accomplish the same purpose. With Sass (we use SCSS but they are the same) we can define mixins, which are small reusable components in our files. We can import and use variables for things like responsive breakpoints or color variables.
By far the most significant piece to using Sass is the ability to logically nest rules within rules. Transpiled it looks the same but it’s much easier to read and update when these files are nested. It’s fast, intuitive, and easy to learn so we don’t require developers with special skills to be able to support it.
Package Name: Sass
Website: https://sass-lang.com/