CSS Anchor Positioning: allow anchor-size() in inset and margin Properties

Category: CSS
Type: Chromium catches up
Status: Enabled by default (Chrome 132)
Intent stage: None

Breaking change: No
Enterprise impact: None
Spec maturity: Working draft
Web Platform Tests: Yes

WPT details: https://wpt.fyi/css/css-anchor-position/anchor-size-parse-valid.html https://wpt.fyi/css/css-anchor-position/anchor-size-001.html

Summary

Allow anchor-size() values for inset and margin properties. Originally, anchor-size() was only allowed in sizing properties. The specification was changed to allow anchor-size() in insets and margins as well.

Standards & signals

Specification: https://drafts.csswg.org/css-anchor-position-1/#anchor-size-fn
Firefox: No signal
Safari: No signal
Web developers: No signals
Tracking bug: https://crbug.com/346521300

Ecosystem

Web Platform Tests: https://wpt.fyi/results/?q=css%2Fcss-anchor-position
Chrome Platform Showcase: https://chrome-platform-showcase.paulkinlan-ea.deno.net/features
GenDN reference: https://gendn.paulkinlan-ea.deno.net/features
chrome.dev demos search: https://www.google.com/search?q=site%3Achrome.dev+CSS%20Anchor%20Positioning%3A%20allow%20anchor-size()%20in%20inset%20and%20margin%20Properties
MDN Web Docs: https://developer.mozilla.org/en-US/search?q=CSS%20Anchor%20Positioning%3A%20allow%20anchor-size()%20in%20inset%20and%20margin%20Properties
Baseline status: https://webstatus.dev/?q=CSS%20Anchor%20Positioning%3A%20allow%20anchor-size()%20in%20inset%20and%20margin%20Properties

View on chromestatus.com