[1] google/closure-stylesheets: A CSS+ transpiler that lints, optimizes, and I18n-izes () https://github.com/google/closure-stylesheets

Closure Stylesheets is an extension to CSS that adds variables, functions, conditionals, and mixins to standard CSS. The tool also supports minification, linting, RTL flipping, and CSS class renaming.

[2] CodeMirror: Closure Stylesheets (GSS) mode () https://codemirror.net/mode/css/gss.html

A mode for Closure Stylesheets (GSS).

MIME type defined: text/x-gss.