1. selector list argument of :nth-child and :nth-last-child CSS pseudo-classes

    The newest versions of `:nth-child()` and `:nth-last-child()` accept an optional `of S` clause which filters the children to only those which match the selector list `S`. For example, `:nth-child(1 of .foo)` selects the first child among the children that have the `foo` class (ignoring any non-`foo` children which precede that child). Similar to `:nth-of-type`, but for arbitrary selectors instead of only type selectors.

  2. CSS3 selectors

    Advanced element selection using selectors including: `[foo^="bar"]`, `[foo$="bar"]`, `[foo*="bar"]`, `:root`, `:nth-child()`, `:nth-last-child()`, `:nth-of-type()`, `:nth-last-of-type()`, `:last-child`, `:first-of-type`, `:last-of-type`, `:only-child`, `:only-of-type`, `:empty`, `:target`, `:enabled`, `:disabled`, `:checked`, `:not()`, `~` (general sibling)

  3. documentfragment api: lastelementchild

  4. document api: lastelementchild

  5. element api: lastelementchild

  6. node api: lastchild

  7. treewalker api: lastchild

  8. css selector: `:last-child`

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

  10. css selector: `:nth-last-child()`

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

  12. css selector: `:nth-last-child()`: `of <selector>` syntax