1. CSS :any-link selector

    The `:any-link` CSS pseudo-class matches all elements that match `:link` or `:visited`

  2. :dir() CSS pseudo-class

    Matches elements based on their directionality. `:dir(ltr)` matches elements which are Left-to-Right. `:dir(rtl)` matches elements which are Right-to-Left.

  3. CSS Filter Effects

    Method of applying filter effects using the `filter` property to elements, matching filters available in SVG. Filter functions include blur, brightness, contrast, drop-shadow, grayscale, hue-rotate, invert, opacity, sepia and saturate.

  4. :focus-visible CSS pseudo-class

    The `:focus-visible` pseudo-class applies while an element matches the `:focus` pseudo-class, and the UA determines via heuristics that the focus should be specially indicated on the element (typically via a “focus ring”).

  5. :focus-within CSS pseudo-class

    The `:focus-within` pseudo-class matches elements that either themselves match `:focus` or that have descendants which match `:focus`.

  6. :is() CSS pseudo-class

    The `:is()` (formerly `:matches()`, formerly `:any()`) pseudo-class checks whether the element at its position in the outer selector matches any of the selectors in its selector list. It's useful syntactic sugar that allows you to avoid writing out all the combinations manually as separate selectors. The effect is similar to nesting in Sass and most other CSS preprocessors.

  7. selector list argument of :not()

    Selectors Level 3 only allowed `:not()` pseudo-class to accept a single simple selector, which the element must not match any of. Thus, `:not(a, .b, [c])` or `:not(a.b[c])` did not work. Selectors Level 4 allows `:not()` to accept a list of selectors. Thus, `:not(a):not(.b):not([c])` can instead be written as `:not(a, .b, [c])` and `:not(a.b[c])` works as intended.

  8. :placeholder-shown CSS pseudo-class

    Input elements can sometimes show placeholder text as a hint to the user on what to type in. See, for example, the placeholder attribute in HTML5. The :placeholder-shown pseudo-class matches an input element that is showing such placeholder text.

  9. CSS :read-only and :read-write selectors

    :read-only and :read-write pseudo-classes to match elements which are considered user-alterable

  10. Element.closest()

    DOM method that returns the current element if it matches the given selector, or else the closest ancestor element that matches the given selector, or else null.

  11. matches() DOM method

    Method of testing whether or not a DOM element matches a given selector. Formerly known (and largely supported with prefix) as matchesSelector.

  12. element api: `beforematch` event

  13. element api: matches

  14. css property: view-transition-name: match-element

  15. css selector: `:any-link`: `:any-link` privacy: selector does not match `<link>` elements

  16. css selector: `:empty`: matches elements with whitespace

  17. css selector: `:first-child`: matches elements with no parent

  18. css selector: `:last-child`: matches elements with no parent

  19. css selector: `:link`: `:link` privacy: selector does not match `<link>` elements

  20. css selector: `:nth-child()`: matches elements with no parent

  21. css selector: `:nth-last-child()`: matches elements with no parent

  22. css selector: `:only-child`: matches elements with no parent

  23. css selector: `:visited`: `:visited` privacy: selector does not match `<link>` elements