/* Colour. Three values, four legal pairings, one swap point.

   Gold belongs to Oscar Shand. Black and cream never change. A project's
   colour is an accent: type and pills on black or cream, never a ground.

   Gold only ever meets black or cream. The legal ink/ground pairings are:
     cream on black · black on gold · black on cream · gold on black
   Gold may set type, but only on black (8.0:1). Cream never sits on gold,
   gold never sits on cream, and a project colour never touches gold —
   it appears only as type or a pill fill on a black or cream surface. */
:root{
  /* ── the three fixed values ─────────────────────────────────── */
  --gold:#C7A365;   /* Oscar Shand. Ground for black type; type on black only. */
  --black:#141416;  /* the only dark. Type on gold and cream, ground for cream and gold type. */
  --cream:#F1EDE4;  /* type on black, and the quiet ground. */

  /* ── the three legal pairings, named ────────────────────────── */
  --surface-brand:var(--gold);--on-brand:var(--black);   /* 8.0:1  */
  --surface-dark:var(--black);--on-dark:var(--cream);     /* 16.1:1 */
  --surface-light:var(--cream);--on-light:var(--black);   /* 16.1:1 */
  --on-dark-accent:var(--gold);                           /* 8.0:1 — gold type, black ground only */

  /* ── the swap point ─────────────────────────────────────────────
     --ground is gold by default because the default context is Oscar
     Shand. A project page or a dark band overrides --ground and
     --on-ground together; nothing else in the system needs to know. */
  --ground:var(--gold);
  --on-ground:var(--black);

  /* hairlines, scrims and secondary ink are DERIVED from the current ground —
     see the derived block below. A custom property substitutes its var()s on
     the element that declares it, so anything referencing --ground or
     --on-ground has to be re-declared in every ground scope or it freezes at
     the root's gold values and inherits that way into black and cream bands. */
  --scrim:color-mix(in srgb,var(--black) 62%,transparent);

  /* ── project colours ────────────────────────────────────────────
     Bright, like the old glow grid: OKLCH L .74–.88, chroma pushed as far
     as sRGB allows. Used as type on black (all clear 6:1+) and as pill
     fills with black text on black or cream. Never a ground, never on gold.
     On cream, type uses --project-ink, the same hue cut to L .46 (base.css). */
  --project-pronto:oklch(.76 .17 52);        /* tangerine   */
  --project-bared:oklch(.78 .15 5);          /* hot pink    */
  --project-m4:oklch(.80 .12 232);           /* sky blue    */
  --project-nichols:oklch(.82 .19 142);      /* lime green  */
  --project-bf-property:oklch(.74 .15 275);  /* lavender    */
  --project-ovsbm:oklch(.74 .19 28);         /* coral red   */
  --project-shop:oklch(.88 .18 96);          /* lemon       */

  /* ── gold's own states ──────────────────────────────────────────
     Hover and press deepen the ground rather than tinting the ink. */
  --gold-deep:#B18E52;
  --gold-deeper:#9C7B43;
}

/* ── derived ──────────────────────────────────────────────────────
   Everything that reads --ground or --on-ground must be re-declared in each
   ground scope. Declaring these only in :root freezes them to gold and the
   frozen value inherits into every band, which is how secondary ink ends up
   at 1.14:1 on black. Add any new ground scope to this selector list.
   data-project is NOT a ground scope: it only sets --project (base.css). */
:root,.ground-gold,.ground-cream,.ground-dark{
  /* secondary copy: the ink pulled toward its own ground, never a grey.
     Holds 5.0:1 on gold, 7.6:1 on cream, 9.6:1 on black. */
  --on-ground-soft:color-mix(in srgb,var(--on-ground) 76%,var(--ground));
  --on-ground-faint:color-mix(in srgb,var(--on-ground) 52%,var(--ground)); /* structure only, never type */

  --hairline:color-mix(in srgb,var(--on-ground) 16%,transparent);
  --hairline-strong:color-mix(in srgb,var(--on-ground) 30%,transparent);
  /* --rule is solid ink, not an alpha hairline. The layout's structural
     divisions are drawn in it: a brutalist grid shows its own construction,
     so a section rule is a real line rather than a suggestion of one.
     --hairline stays for minor divisions inside a block. */
  --rule:var(--on-ground);

  --ground-hover:color-mix(in srgb,var(--ground) 88%,var(--black));
  --ground-press:color-mix(in srgb,var(--ground) 79%,var(--black));

  /* semantic text roles */
  --text-primary:var(--on-ground);
  --text-secondary:var(--on-ground-soft);
  --text-muted:var(--on-ground-faint);
  --text-inverse:var(--cream);

  --surface-page:var(--ground);
  --surface-card:var(--ground);
}