Originally CSS was handled directly by browser without any processing beforehand, modern CSS tooling has empowered CSS with many features beyond the language itself to fix CSS problems at scale and often baked inside web frameworks.
The evolution of CSS tooling started with CSS preprocessors like Sass and recently blossomed with PostCSS and web bundlers.
There are countless ways to setup CSS tooling properly depending the combination of following factors:
Setting up and customizing CSS transformation to your specific use case takes time. It’s recommended to use a web framework that has following popular tools configured perfectly:
PostCSS has been widely adopted in modern web development, flexible enough to integrate with any task runners and module bundlers, has more than 200 plugins, and will have a great impact on how we write CSS in a foreseeable future.