CSS Custom Properties

Noun · Development

Definitions

  1. Native CSS variables declared with -- prefix and accessed via var(). Unlike preprocessor variables (Sass $vars), custom properties are live in the browser, cascade through the DOM, can be updated with JavaScript, and enable dynamic theming. The foundation of modern CSS design systems.

    In plain English: Variables built into CSS that you can change at any time, enabling dynamic themes and consistent design without a preprocessor.

    Example: "Set --primary-color on :root and use var(--primary-color) everywhere — toggling dark mode just swaps the root variables."

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