/* ─────────────────────────────────────────────────────────────
   Openflow — design tokens
   Patina Workshop: warm dark iron, copper accents, mono-first.
   All neutrals tinted ~50° so the surface reads like aged metal,
   not graphite. Chroma backed off at the dark extreme so the page
   stays comfortable on a bright monitor.
   ───────────────────────────────────────────────────────────── */

:root {
  /* Surfaces */
  --iron-0:       oklch(18% 0.015 50);
  --iron-1:       oklch(22% 0.015 50);
  --iron-2:       oklch(27% 0.018 48);
  --iron-3:       oklch(34% 0.018 45);

  /* Ink */
  --ash:          oklch(60% 0.015 50);
  --bone:         oklch(92% 0.012 65);
  --highlight:    oklch(98% 0.010 70);

  /* Accent (copper). Used sparingly — never more than ~6% of any viewport. */
  --copper:       oklch(70% 0.14 50);
  --copper-deep:  oklch(58% 0.13 45);
  --copper-glow:  oklch(76% 0.10 60);

  /* Type stacks */
  --sans: 'IBM Plex Sans', system-ui, sans-serif;
  --mono: 'IBM Plex Mono', ui-monospace, monospace;

  /* Page rhythm */
  --gutter: 40px;
  --wrap-max: 1180px;
  --rhythm-xs: 16px;
  --rhythm-sm: 24px;
  --rhythm-md: 40px;
  --rhythm-lg: 64px;
  --rhythm-xl: 96px;
  --rhythm-2xl: 140px;

  /* Motion */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-fast: 240ms var(--ease-out);
}