:root
:root
该:rootCSS伪类与表示该文档的文档树的根元素相匹配。在HTML中，:root表示<html>元素，并且与选择器html相同，只是其特异性更高。
/* Selects the root element of the document */
/* <html> in the case of HTML */
:root {
background: yellow;
}
语法
:root
实例
:root 可以用于声明全局CSS变量：
:root {
--main-color: hotpink;
--pane-padding: 5px 42px;
}
规范
| Specification | Status | Comment |
|---|---|---|
| Selectors Level 4The definition of ':root' in that specification. | Working Draft | No change |
| Selectors Level 3The definition of ':root' in that specification. | Recommendation | Initial definition |
浏览器兼容性
| Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|---|
| Basic support | 1 | (Yes) | 1.0 (1.7 or earlier) | 9 | 9.5 | 1.0 |
| Feature | Android | Edge | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|
| Basic support | ? | (Yes) | ? | ? | ? | ? |
