Simple CSS Selector-Hierarchy Selector

Simple CSS Selector-Hierarchy Selector

* CSS level selector has 4

* 1. Descendant selector: $ (' div p '), in all descendants (descendants) of the ancestor element, query the specified element

* 2. Child element selector: $ (' div > P '), find in all child elements of parent element

* 3. Adjacent selector: $ ('. Top + li '), select the immediate sibling adjacent element of the current element

* 4. Brother selector: $ ('. Top ~ li '), select all sibling elements behind the current element

<! DOCTYPE html>