BasicsIntermediate

Custom Properties (CSS Variables)

Declare global variable roots, handle fallback values, and mutate styles dynamically in browser scripts.

CSS Custom Variables

CSS variables allow declaring reuse values globally.

Variables are declared inside selectors (usually `:root`) and referenced using the `var()` keyword: ```css :root { --primary-color: #2563eb; }

.button { background-color: var(--primary-color); } ```