Is that `attr()` at all or just the expanded version which allows different units and fallbacks?
https://developer.mozilla.org/en-US/docs/Web/CSS/attr#Browse... goes back far enough that I'd be surprised if they'd drop a feature which has been around for such a long period of time or that the browsers vendors would do anything other than ignore the spec until it was corrected.
https://developer.mozilla.org/en-US/docs/Web/CSS/attr#Browse... goes back far enough that I'd be surprised if they'd drop a feature which has been around for such a long period of time or that the browsers vendors would do anything other than ignore the spec until it was corrected.