[1] [selectors-4] Add :is(), resolves #1170 (LeaVerou著, ) <https://github.com/w3c/csswg-drafts/commit/5948b1ce37463aa7f87fede040fac9dd2c233329>
[2] [selectors] Functional pseudo-class like :matches() with 0 specificity · Issue #1170 · w3c/csswg-drafts () <https://github.com/w3c/csswg-drafts/issues/1170>
[3] [selectors-4] Add :is() example in specificity section, and add it in… (LeaVerou著, ) <https://github.com/w3c/csswg-drafts/commit/a9fddaf185d9885bd657cd222956bccc35486939>