.scss File — Sassy CSS

SCSS (Sassy CSS) is the most popular syntax variant of Sass (Syntactically Awesome Style Sheets), a CSS preprocessor that extends CSS with programming features. SCSS files use a superset of CSS syntax — all valid CSS is also valid SCSS — plus variables ($color: #333), nesting for hierarchical selectors, mixins for reusable style groups, functions for computed values, partials for modular file organization, extends for inheritance, and control flow (if/else, for, each, while). SCSS must be compiled to standard CSS before browsers can use it, typically through the sass CLI tool, webpack, Vite, or other build tools. SCSS has been the dominant CSS preprocessor since the early 2010s, used by major CSS frameworks including Bootstrap (v4+), Foundation, and Bulma. The format enables DRY (Don't Repeat Yourself) CSS development with modular architecture patterns like BEM, SMACSS, and ITCSS. SCSS variables and mixins are powerful for maintaining consistent design tokens (colors, spacing, typography) across large projects. While modern CSS custom properties have reduced some need for preprocessors, SCSS's nesting, mixins, and modular organization remain valuable for large-scale CSS architecture.