New Stylesheet resource

[victordcq]

You could do it with :has() on updated browsers

html:has(> head link[href$="dark.css"]) {
--test: blue;
}

html:has(> head link[href$="light.css"]) {
--test: red;
}

[ziad]

Nice, thank you. Works in browser, just not in Designer. But that's ok, I can get around it.