The :modal pseudo-class selects elements that put other elements into a non-interactive state, such as a fullscreen element or a <dialog> element used with showModal().

The ::backdrop CSS pseudo-element is a box underneath an element in the top layer, such as a <dialog>. It can be used to create obscuring effects distinguishing a modal element from the elements underneath.

The :focus-visible CSS pseudo-class selects elements that match the :focus pseudo-class and meets the browser's criteria for visually emphasizing focused elements.