Solid is BuzzFeed's CSS style guide. Influenced by frameworks like Basscss, Solid uses immutable, atomic CSS classes to rapidly prototype and develop features, providing consistent styling options along with the flexibility to create new layouts and designs without the need to write additional CSS. Additionally, a few globally-reusable HTML and CSS components are available to help new apps spin up quickly without having to reinvent the wheel each time (with more on the way).
You can check out the code and on GitHub.
In your project directory:
npm install --save bf-solid
Use Sass to build solid into your project. We use grunt sass, here's a sample configuration.