Can WebExtensions actually somehow overwrite the result of a media query?
I mean, for JS window.matchMedia()
this is likely easy: Just inject a content script that overwrites that JS function.
But if “real” CSS media queries (inside css files) are used, this is not really possible, is it?
Some background: If you wonder why, my use case would be to overwrite the new prefers-color-scheme
CSS media feature introduced in Firefox 67. (It’s not currently available for any other browsers that support browser/WebExtensions.)
Cross-posted on Stackoverflow.