Depends on 3 packages(full list with versions):

Clay

build Hackage

Clay is a CSS preprocessor like LESS and Sass, but implemented as an embedded domain specific language (EDSL) in Haskell. This means that all CSS selectors and style rules are first class Haskell functions, which makes reuse and composability easy.

The project is described on the project homepage.

The API documentation can be found in the top level module Clay.