The Cascading Style Sheets (CSS) Working Group has published a Last Call Working Draft of CSS Custom Properties for Cascading Variables Module Level 1. This module introduces cascading variables as a new primitive value type that is accepted by all CSS properties, and custom properties for defining them. CSS is a language for describing the rendering of structured documents (such as HTML and XML) on screen, on paper, in speech, etc. Comments are welcome through 3 June 2014. Learn more about the Style Activity.