Check out the style-elements[0] package and the author's talk at Elm Europe introducing it[1]. It outputs HTML and CSS but doesn't base its semantics on either.

It has a clean-slate design, and there's a ton of buzz in the Elm community about it. :)

[0] http://package.elm-lang.org/packages/mdgriffith/style-elemen...

[1] https://www.youtube.com/watch?v=NYb2GDWMIm0