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CSS Root Font Units: 'rex', 'rch', 'ric', 'rlh'

Category

CSS

Type

Chromium catches up

Status

Enabled by default (Chrome 111)

Intent stage

Prepare to ship

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

WPT details: https://wpt.fyi/results/css/css-values/rlh-invalidation.html?label=experimental&label=master&aligned https://wpt.fyi/results/css/css-values/rch-invalidation.html?label=experimental&label=master&aligned https://wpt.fyi/results/css/css-values/ric-invalidation.html?label=experimental&label=master&aligned https://wpt.fyi/results/css/css-values/rex-invalidation.html?label=experimental&label=master&aligned

Summary

Adds root font units. Previously, only 'rem' has been supported in Chrome. This feature adds root element variants of ex, ch, ic, and lh.

Motivation

There is already support for non-root versions of these elements and per standard there should also be root versions

Standards & signals

• Specification: https://www.w3.org/TR/css-values-4/#font-relative-lengths
• Firefox: Positive
• Safari: Support
• Web developers: No signals
• Tracking bug: https://bugs.chromium.org/p/chromium/issues/detail?id=1381037

Ecosystem

• Web Platform Tests: https://wpt.fyi/results/?q=css%2Fcss-values%2Frlh-invalidation
• 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%20Root%20Font%20Units%3A%20'rex'%2C%20'rch'%2C%20'ric'%2C%20'rlh'
• MDN Web Docs: https://developer.mozilla.org/en-US/search?q=CSS%20Root%20Font%20Units%3A%20'rex'%2C%20'rch'%2C%20'ric'%2C%20'rlh'
• Baseline status: https://webstatus.dev/?q=CSS%20Root%20Font%20Units%3A%20'rex'%2C%20'rch'%2C%20'ric'%2C%20'rlh'

View on chromestatus.com