I've been googling how to add custom classes to the HTML tag of a Wordpress theme, but it's a tricky issue to research because all results are about HTML tags in general, not the specific HTML tag that opens a document. I want something like this:
I know the
body_class filter can be used to customize the body's classes, but there seems to be no such thing for the html tag, yet Wordpress does output some classes for
<html>, so they must be coming from somewhere...