The CSS Working Group has published the following three First Public Working Drafts:
- CSS Containment Module Level 3: This CSS module describes the ‘contain’ property, which indicates that the element’s subtree is independent of the rest of the page. This enables heavy optimizations by user agents when used well.
- CSS Conditional Rules Module Level 5: This module contains the features of CSS for conditional processing of parts of style sheets, based on capabilities of the processor or the environment the style sheet is being applied in. It includes and extends the functionality of CSS Conditional 4 [css-conditional-4], adding the generalized conditional rule ‘@when’ and the chained conditional rule ‘@else’, as well as introducing font processing queries to the supports query syntax used in ‘@supports’ rules.
- CSS Cascading and Inheritance Level 6: This CSS module describes how to collate style rules and assign values to all properties on all elements. By way of cascading and inheritance, values are propagated for all properties on all elements. New in this level is § 2.5 Scoped Styles.
CSS is a language for describing the rendering of structured documents (such as HTML and XML) on screen, on paper, etc.