CSS WG Blog CSS Values and Units Level 4 Update

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CSS Values and Units Level 4 Update

By fantasai December 31, 2021 (Permalink)
Categories: publications

The CSS Working Group has published an updated Working Draft of CSS Values and Units Level 4. This specification defines the CSS property definition grammar, and
the value types that are common across many specs, such as <length> or

This update defers the toggle() and attr() functions to Level 5, and includes a first draft of integration with the Fetch specification. Other changes since the last WD are largely error corrections and refinement of existing features, see full changes list. We expect this to be the full feature set for Level 4, and will be working to resolve the remaining open issues in preparation for a transition to Candidate Recommendation.

Existing Level 4 additions since Level 3 include mix() notation, src() notation, a variety of new viepwort units, typographic units for ideographic characters and line-height-relative measurements, and a slew of math functions including comparisons, rounding, and trigonometry. Future additions will go into Level 5.

Please send feedback by either filing an issue in GitHub (preferable) or sending mail to the (archived) public mailing list www-style@w3.org with the spec code ([css-values-4]) and your comment topic in the subject line. (Alternatively, you can email one of the editors and ask them to forward your comment.)

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Last updated 2021-12-31 23:51:18