/* Basecamp — shared tokens.
   The hub owns these values. Each subject page loads assets/subjects/<slug>.css
   AFTER this file and overrides the palette, the fonts and the motif.
   Everything structural (scale, rhythm, radii, motion) stays shared, so eight
   very different-looking pages still read as one site. */

:root {
  color-scheme: light dark;

  /* ---- Type ------------------------------------------------------------ */
  /* Subjects override --font-display / --font-text / --font-mono only. */
  --font-display: "Archivo", ui-sans-serif, system-ui, sans-serif;
  --font-text: "Newsreader", ui-serif, Georgia, serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;

  /* Fluid scale, 1.25 minor third at the small end, opening up on wide screens. */
  --t--1: clamp(0.75rem, 0.72rem + 0.15vw, 0.82rem);
  --t-0: clamp(0.94rem, 0.90rem + 0.20vw, 1.05rem);
  --t-1: clamp(1.13rem, 1.06rem + 0.33vw, 1.31rem);
  --t-2: clamp(1.35rem, 1.23rem + 0.58vw, 1.72rem);
  --t-3: clamp(1.62rem, 1.40rem + 1.05vw, 2.36rem);
  --t-4: clamp(1.94rem, 1.55rem + 1.90vw, 3.24rem);
  --t-5: clamp(2.33rem, 1.65rem + 3.35vw, 4.45rem);
  --t-6: clamp(2.80rem, 1.60rem + 5.90vw, 6.10rem);

  --lh-tight: 1.04;
  --lh-snug: 1.22;
  --lh-text: 1.62;

  /* ---- Space ----------------------------------------------------------- */
  --s-1: 0.25rem;
  --s-2: 0.5rem;
  --s-3: 0.75rem;
  --s-4: 1rem;
  --s-5: 1.5rem;
  --s-6: 2rem;
  --s-7: 3rem;
  --s-8: 4.5rem;
  --s-9: 7rem;

  --gutter: clamp(1rem, 4vw, 3rem);
  --measure: 68ch;
  --wrap: 78rem;
  --wrap-narrow: 46rem;

  /* ---- Colour ---------------------------------------------------------- */
  /* Hub identity: warm survey paper, graphite ink, one signal orange.
     The accent has exactly one job — "this is where you are / do this next". */
  --paper: #f4f1e9;
  --paper-2: #ebe7dc;
  --paper-3: #e0dbcc;
  --ink: #15181a;
  --ink-2: #3f4549;
  --ink-3: #6d757a;
  --rule: #cfc9b9;
  --rule-soft: #ded8c9;

  --accent: #d94f22;
  --accent-ink: #ffffff;
  --accent-soft: #f6ddd2;

  /* A quiet second hue for contour lines, plot grids and chart fills.
     Never used for emphasis — that is the accent's job alone. */
  --trace: #6f7f6a;
  --trace-soft: #b9c3b2;

  --shadow-1: 0 1px 2px rgb(21 24 26 / 0.05), 0 2px 8px rgb(21 24 26 / 0.04);
  --shadow-2: 0 2px 4px rgb(21 24 26 / 0.06), 0 12px 32px rgb(21 24 26 / 0.09);

  --radius-1: 3px;
  --radius-2: 6px;
  --radius-3: 12px;

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --dur: 220ms;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #101314;
    --paper-2: #171b1d;
    --paper-3: #1f2426;
    --ink: #e9e5da;
    --ink-2: #b3ada0;
    --ink-3: #82877f;
    --rule: #2c3234;
    --rule-soft: #232829;

    --accent: #ff7043;
    --accent-ink: #1a0d07;
    --accent-soft: #35211a;

    --trace: #8fa389;
    --trace-soft: #3a443a;

    --shadow-1: 0 1px 2px rgb(0 0 0 / 0.4), 0 2px 8px rgb(0 0 0 / 0.3);
    --shadow-2: 0 2px 4px rgb(0 0 0 / 0.45), 0 12px 32px rgb(0 0 0 / 0.5);
  }
}

:root[data-theme="dark"] {
  --paper: #101314;
  --paper-2: #171b1d;
  --paper-3: #1f2426;
  --ink: #e9e5da;
  --ink-2: #b3ada0;
  --ink-3: #82877f;
  --rule: #2c3234;
  --rule-soft: #232829;

  --accent: #ff7043;
  --accent-ink: #1a0d07;
  --accent-soft: #35211a;

  --trace: #8fa389;
  --trace-soft: #3a443a;

  --shadow-1: 0 1px 2px rgb(0 0 0 / 0.4), 0 2px 8px rgb(0 0 0 / 0.3);
  --shadow-2: 0 2px 4px rgb(0 0 0 / 0.45), 0 12px 32px rgb(0 0 0 / 0.5);
}

/* Each subject sets --subject-accent and --subject-trace; these aliases let
   shared components pick them up without knowing which subject they are on. */
:root {
  --subject-accent: var(--accent);
  --subject-trace: var(--trace);
}