:nth-child() of <selector>The of syntax for the :nth-child() and :nth-last-child() CSS functional pseudo-classes match elements by the relative position of elements, counted from the first or last sibling matching a selector list.selectorsSelectorswidely2023-05-092025-11-09https://drafts.csswg.org/selectors-4/#the-nth-child-pseudohttps://drafts.csswg.org/selectors-4/#the-nth-last-child-pseudocss-nth-child-ofhttps://developer.mozilla.org/docs/Web/CSS/Reference/Selectors/:nth-childcss.selectors.nth-child.of_syntaxcss.selectors.nth-last-child.of_syntaxhttps://nowyoucanuse.com/features--nth-child-of.html