Just like with :is() and :not(), the specificity of :has() is replaced by the specificity of the most specific selector in its selector list argument. Unlike :nth-child() or :link, :has() itself doesn't add to the specificity.
There are two methods you can use to open a <dialog> element, show() and showModal(). show() opens a dialog on top of the rest of the content, but you can still interact with content beneath. showModal() opens a modal dialog with a backdrop on top of the rest of the content, and you can’t interact with the rest of the page.
Functional color notations that existed before CSS Color Module Level 4 (rgb(), rgba(), hsl(), hsla()) used to only except comma-separated lists of arguments. That changes with Module Level 4, now you can also provide space-separated arguments.
I was wondering what happens with HTML elements in web components when I add styles to the document. Under which circumstances do global styles defined in a style element or external stylesheet apply to these elements?