CSS 3 selector Root, not, empty, target

1.root Selector

The root selector binds the style to the root element of the page. The root element is the element that is the topmost structure in the document tree, which in the HTML page refers to the "

2.not Selector

If you want to use a style for a structure element, but want to exclude the sub-structure element below the structure element so that it does not use this style, you can use the not selector.

3.empty Selector

Use the empty selector to specify the style to use when the content in the element is blank.

4.target Selector

Use the target selector to specify a style for a target element in the page that is used as a hyperlink in the page, which works only when the user taps the hyperlink in the page and jumps to the target element.

CSS 3 selector Root, not, empty, target