https://www.npmjs.com/package/postcss-js
https://github.com/postcss/postcss-js

2017
https://medium.com/making-internets/better-css-with-javascript-88463deecf3
2016
https://blog.grommet.io/post/2016/08/10/css-in-js-may-not-be-the-solution-to-all-your-problems