CaDDS or Config and Data Driven Styling is a styling methodology based on styling a complete project from one single config file. It might sound odd, but it's possible without making it too complicated.
The idea is to create a config file which holds all the styling for a project. By including this file into another with some different defaults, you can completely alter the outcome and create themes.
The idea is to create css which can be altered as much as possible and be able to build that css just using a config file.
To use the CADDS styling you need to make sure your project has a few things in stock; Knowledge of the CSS cascade, BEM and install CaDDS and Sass in your project.
npm install cadds sass