CSS Feature Support Checker

Test CSS feature support on any browser - smart TVs, embedded devices, and non-standard environments.

Custom Properties

CSS custom properties (variables) and functions for dynamic styling.

⏳ CSS Custom Properties (Variables)
Define and use custom CSS variables with -- prefix.
--custom: redMDN
⏳ var()
Reference custom properties using the var() function.
color: var(--custom)MDN