`:root` CSS pseudo-class

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.

The :root CSS pseudo-class matches the root element of a tree representing the document. In HTML, :root represents the <html> element and is identical to the selector html, except that its specificity (0-1-0) is higher than html's (0-0-1).

/* Selects the root element of the document:
   <html> in the case of HTML */
:root {
  background: yellow;
}

Syntax

:root {
  /* ... */
}

Examples

Declaring global CSS variables

:root can be useful for declaring global CSS variables:

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

Specifications

Specification
Selectors Level 4 # root-pseudo

Browser compatibility