Pseudo-elements are used to create some elements that do not exist in the original dom structure tree. For example, ::before, ::after add content to some existing elements, it will be displayed in specific UI, but these content will not appear in dom
Pseudo-class means that an existing element is in a certain state, but the style of different states cannot be expressed through the dom tree.
What are the pseudo-class selectors:
- E: last-child selects the last child element of the parent element
- EE: nth-child(n) selects the nth element of the parent element
- E: nth-last-child(n) selects the last nth element E of the parent element, which must meet the nth last element and be the E tag, otherwise it is invalid
- E: first-of-type selects the first element of the same label that meets the conditions
- E: last-of-type selects the last element of the same tag that meets the conditions
- E: nth-of-type(n) selects the nth element of the same label that meets the conditions