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CSS Custom Properties Variables

April 5, 2026

CSS Custom Properties System

Dynamic theming, design tokens, CSS-in-JS integration.

Design Tokens

:root {
  --color-primary: #007bff;
  --color-secondary: #6c757d;
  --spacing-xs: 0.25rem;
  --spacing-s: 0.5rem;
  --spacing-m: 1rem;
  --spacing-l: 2rem;
  --radius: 8px;
}

.card {
  background: var(--color-background, white);
  padding: var(--spacing-m);
  border-radius: var(--radius);
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

Dynamic Values

  • calc(var(--spacing-l) * 2)
  • color-mix(in srgb, var(--primary) 20%, black)
  • var(--prop, fallback)