Style guides written and maintained by top tech companies
github.com
A mostly reasonable approach to CSS and Sass
Dropbox’s (S)CSS authoring style guide
make.wordpress.org
A baseline for collaboration and review within various aspects of the WordPress open source project and community
google.github.io
This document defines formatting and style rules for HTML and CSS
codeguide.co
Standards for developing consistent, flexible, and sustainable HTML and CSS.
This is the Code Style guide for CSS
This is the coding style guide we use for writing CSS & Sass in Workable.
codepen.io
Inspired by Mark Otto's tour of GitHub's CSS and Ian Feather's tour of Lonely Planet's CSS
