.sass File — Indented Sass Syntax

SASS (Syntactically Awesome Style Sheets) in its original indented syntax uses whitespace and newlines instead of curly braces and semicolons to define CSS rules. Created by Hampton Catlin and designed by Natalie Weizenbaum in 2006, the indented .sass syntax was the original Sass format before the SCSS syntax was introduced. SASS files use indentation to nest selectors (similar to Python or YAML), eliminating the need for curly braces, and line breaks replace semicolons between property declarations. The indented syntax is more concise than SCSS but less familiar to developers coming from CSS, since all valid CSS is valid SCSS but not valid SASS. Both .sass and .scss files support the same feature set — variables, mixins, extends, functions, imports, and control directives — just with different syntactic styles. The indented syntax has a smaller user base than SCSS but is preferred by developers who value brevity and clean visual structure, particularly in the Ruby community where Sass originated. The sass compiler processes both syntaxes identically, producing the same CSS output. Both formats can import from each other within the same project.