/* ============================================================================
   Karvan Group — design tokens
   Light palette on bare :root; dark palette redefines the same names only.
   Every literal colour, size and duration in the system lives here.
   Contrast measured 2026-09-19, see docs/AI/QA-EVIDENCE.md.
   ========================================================================== */

:root {
  /* --- surface and ink ------------------------------------------------- */
  --ground: #f7f5f1;        /* warm paper */
  --surface: #fffdf9;       /* raised paper */
  --ink: #141410;           /* 16.96:1 on ground */
  --ink-muted: #5a5750;     /*  6.62:1 on ground */
  --rule: #d8d3c8;          /* decorative hairline, conveys no information */
  --rule-strong: #8a857a;   /*  3.37:1 — borders that carry structure */
  --accent: #1f4b3f;        /*  9.03:1 on ground — deep pine */
  --accent-wash: rgba(31, 75, 63, 0.07);
  --accent-ink: #f7f5f1;    /* text on an accent fill */

  /* --- type ------------------------------------------------------------ */
  --font-sans: "IBM Plex Sans", ui-sans-serif, system-ui, -apple-system,
    "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas,
    monospace;

  --t-display: clamp(2.75rem, 1.55rem + 5.4vw, 5.5rem);
  --t-h1: clamp(2rem, 1.3rem + 3.2vw, 3.5rem);
  --t-h2: clamp(1.375rem, 1.1rem + 1.3vw, 2rem);
  --t-h3: clamp(1.0625rem, 1rem + 0.3vw, 1.25rem);
  --t-lead: clamp(1.125rem, 1.04rem + 0.42vw, 1.375rem);
  --t-body: 1.0625rem;
  --t-sm: 0.9375rem;
  --t-label: 0.6875rem;

  --lead-tight: 1;
  --lead-snug: 1.18;
  --lead-normal: 1.62;
  --lead-lead: 1.5;

  --track-display: -0.03em;
  --track-label: 0.14em;
  --track-wordmark: 0.2em;

  /* --- space (4px base) ------------------------------------------------- */
  --s1: 0.25rem;
  --s2: 0.5rem;
  --s3: 0.75rem;
  --s4: 1rem;
  --s5: 1.5rem;
  --s6: 2rem;
  --s7: 3rem;
  --s8: 4rem;
  --s9: 6rem;
  --s10: 8rem;

  /* --- layout ----------------------------------------------------------- */
  --gutter: clamp(1.25rem, 5vw, 4rem);
  --shell: min(78rem, 100% - 2 * var(--gutter));
  --rail: 13rem;
  --measure: 62ch;
  --radius: 2px;

  /* --- motion ----------------------------------------------------------- */
  --dur: 130ms;
  --ease: cubic-bezier(0.2, 0, 0, 1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --ground: #121210;
    --surface: #1a1a17;
    --ink: #edeae3;        /* 15.61:1 on ground */
    --ink-muted: #a8a49b;  /*  7.55:1 on ground */
    --rule: #32312b;
    --rule-strong: #6a685f; /* 3.36:1 */
    --accent: #5fa88e;      /* 6.68:1 on ground */
    --accent-wash: rgba(95, 168, 142, 0.1);
    --accent-ink: #121210;
  }
}