Add a unique class to HTML tag/element
I know there is a body_class function for WordPress. But is there one (or a way) to add a class to the HTML element?
My goal is to be able to add a unique class (or ID) to a page’s HTML element. Currently my theme is adding the page-id-XXXX class to the body element, but I need a way to have a unique class or ID on the actual HTML element. I’d probably be fine having the page-id-XXXX also added onto the HTML element, although I’d prefer being able to have a custom field that’s added to each page, where I can type in the class/ID that would then get added to the HTML element.
At the very least, is there a function I can use to add a class or ID to the HTML element, similar to how the body_class function works?