Firstile CSS is a modular, Sass-based CSS framework that provides a structured approach to building CSS stylesheets. This project is built around a robust system of components, each categorizing a specific set of HTML elements. These components include normalization, base, style collections, and modules, enabling you to apply consistent, modular styling. Moreover, they ensure that only the relevant custom variables are included in the root context, optimizing your stylesheet and maintaining a clean, efficient codebase. Firstile CSS is perfect when you want to create a bunch of optimal CSS files each requiring specific styling goals.