In https://github.com/w3c/csswg-drafts/issues/11645#issuecomment-2701601350 it was resolved to replace `string` attr() type with `raw-string`, see: https://drafts.csswg.org/css-values-5/#attr-notation. Change attr() syntax, so that `attr(data-foo string)` will now become `attr(data-foo raw-string)`.