@chriskirknielsen This would not work because the function spits out idents, not strings.
And even if it could be converted into a string it would most likely not be allowed for privacy reasons.
(The redesigned attr() for example is rightfully prevented from being used in URLs, as one could steal user-data that way)
@bramus Figured as much, just looked like they could achieve a similar result (thought with a different output type), but the privacy and security reasons are definitely a concern. Has this data exfiltration issue basically killed all hopes of building dynamic URLs in CSS (if you know)? Which is understandable, but still a little sad.