I've gotten good with Sass, but I make a strong effort not to get overly comfortable with any technology. Sticking with any library for more than 6 months is how I'll know it's time to quit tech and work on my carpentry skills.
> PostCSS is a tool for transforming CSS with JS plugins. These plugins can support variables and mixins, transpile future CSS syntax, inline images, and more.
> [...] PostCSS can do the same work as preprocessors like Sass, Less, and Stylus. But PostCSS is modular, 3-30 times faster, and much more powerful.
