@AmeliaBR @amxmln that’s a good point. in this case, author styles are applied initially, and only once someone tries to autofill and the proprietary pseudoclass gets applied does it (try to) go to the !important UA styles. I should clarify that in my post, because this trick only works under those circumstances.
@noleli @amxmln Also, separate issue: but I hope you have a real good reason for overriding user agent !important styles if you're using this in practice & not as just a weird CSS trick.