Custom properties
Widely available since 2019-10-05
Custom properties are CSS properties prefixed with -- that set values you can reuse with the var() function. For example, you can set a --key-color property to reuse as border-color: var(--key-color). Also known as CSS variables.
Learning resources on MDN
Browser support (view on caniuse.com)
- Chrome 49 Released on 2016-03-02
- Chrome Android 49 Released on 2016-03-09
- Edge 15 Released on 2017-04-05
- Firefox 31 Released on 2014-07-22
- Firefox for Android 31 Released on 2014-07-22
- Safari 9.1 Released on 2016-03-21
- Safari on iOS 9.3 Released on 2016-03-21