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This blog post by Chris Coyier outlines the CSS at CodePen. CodePen uses SCSS as its preprocessor and
According to Mark Otto, co-creator of Bootstrap and designer at GitHub, the code-hosting site uses SCSS as its preprocessor. The site has over 100 individual source stylesheets that then gets compiled down to only two stylesheets for production.
Ian Feather wrote about CSS development at Lonely Planet (the travel guide publisher). The site uses Sass and follows a modified
Hootsuite, a social-media-management app, has over 40 engineers, and four of them are dedicated to HTML and CSS. The app’s preprocessor is LESS, follows a CSS philosophy inspired by BEM and
Brian Lovin, Product Manager at Buffer, wrote about their app’s CSS where he mentions they use
This blog post by Bobby Grace, designer at Trello, a web-based project management application, talks about the app’s CSS. The post outlines the stylesheet file structure, the tools they use (like CSS Shrink to reduce their stylesheets’ file sizes) their CSS-coding style, and more.