Every v1 utility reads from CSS custom properties. That made the frozen framework themeable years before "design tokens" became industry vocabulary.

The families#

FamilyVariablesConsumed by
Spacing--space-0--space-9m-*, p-*, gap-*
Type scale--text-1--text-5fluid text-* sizes
Palettes--neon-* --pastel-* --brutal-* --mono-*text-*, bg-*, border-*

Override responsibly#

css
:root {
  --neon-cyan-500: hsl(190 100% 60%);
}

Redefine after the v1 link tag; components that consume the variable restyle automatically.