coderef

:rootBaseline · Widely available

The :root pseudo-class matches the root element of the document, usually the <html> element.

Supported in all major browsers for at least 30 months — safe to use without fallbacks. Baseline since Jul 29, 2015. Widely available since Jan 29, 2018.

How to use ↓Compare browsers

Browser support

DesktopChrome
1+Supportedsince Dec 11, 2008
Current: 155
Edge
12+Supportedsince Jul 29, 2015
Current: 154
Firefox
1+Supportedsince Nov 9, 2004
Current: 157
Safari
1+Supportedsince Jun 23, 2003
Current: 27
MobileChrome Android
18+Supportedsince Jun 27, 2012
Current: 155
Firefox Android
4+Supportedsince Mar 29, 2011
Current: 157
Safari iOS
1+Supportedsince Jun 29, 2007
Current: 27

How to use

This feature is Baseline widely available — use it freely, no fallback needed.

Example

Full syntax and examples are on MDN: :root.

Feature detection

CSS · check before using
@supports selector(:root) {
  /* styles that use :root */
}

/* or in JavaScript */
if (CSS.supports("selector(:root)")) {
  // use it
}

Documentation (MDN)

Specification