Allows custom counter styles (@counter-style rules) to be defined with shadow trees, and properly referenced within shadow trees or across shadow boundaries.
Motivation
Currently, if we want to use a custom counter style in shadow trees, the counter style must be defined in the global namespace (i.e., in the light DOM), which breaks encapsulation. This can be fixed if we allow shadow trees to define their own custom counter styles and handle name scoping and conflicts correctly.
Documentation
Specification
Specification currently under development in a Working Group
Status in Chromium
Enabled by default
(tracking bug)
Consensus & Standardization
After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.
Owner
Intent to Prototype url
Intent to Prototype threadSearch tags
css, counter, counter-style, shadow,Last updated on 2021-12-20
Comments
This is part of the feature https://chromestatus.com/feature/5692693659254784. They were implemented together during prototyping. However, this feature was held back from shipping because the spec wasn't ready until a later CSSWG resolution https://github.com/w3c/csswg-drafts/issues/1995#issuecomment-848941922.