CSS pseudo classes All In One
CSS 伪类
https://developer.mozilla.org/en-US/docs/Web/CSS/Pseudo-classes
W3C
https://drafts.csswg.org/selectors-3/
https://drafts.csswg.org/selectors-4/
https://drafts.csswg.org/css-ui-3/
https://html.spec.whatwg.org/multipage/#pseudo-classes
https://fullscreen.spec.whatwg.org/
:hover & :focus & :visited
:valid & :invalid
:first & :first-child & :first-of-type
:last-child & :last-of-type
:nth-child() & :nth-of-type() & :nth-last-child() & :nth-last-of-type()
:picture-in-picture
画中画
:enabled
...