JSS is a more powerful abstraction over CSS. It uses JavaScript as a language to describe styles in a declarative and maintainable way. It is a high performance JS to CSS compiler which works at runtime and server-side. This core library is low level and framework agnostic. It is about 6KB (minified and gzipped) and is extensible via plugins API.
Feel free to ask any JSS related questions on twitter by using hashtag #cssinjs and mentioning @oleg008, watch my latest talk about “Unique Value Proposition of CSSinJS” and try it on a playground.
If you are a Sass (SCSS) user, this course will show how to express popular Sass language features using latest JavaScript features: Convert SCSS (Sass) to CSS-in-JS.