:root

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

:root 这个 CSS 伪类匹配文档树的根元素。对于 HTML 来说,:root 表示 <html> 元素,除了优先级更高之外,与 html 选择器相同。

css
/* 选择文档的根元素(HTML 中的 <html>) */
:root {
  background: yellow;
}

语法

css
:root {
  /* ... */
}

示例

声明全局 CSS 变量

在声明全局 CSS 变量:root 会很有用:

css
:root {
  --main-color: hotpink;
  --pane-padding: 5px 42px;
}

规范

Specification
Selectors Level 4
# root-pseudo

浏览器兼容性

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
:root

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support

参见