/* ============================================================
   AI ADVANCED INC — DESIGN TOKENS
   Identity Rev B · Mark 31, "The Clearing"
   ------------------------------------------------------------
   One silhouette, one ink, one spot.
   The mark is ink only, always. Cyan carries interactive
   elements and callouts. Magenta appears once a page at most.
   No red, ever — a red delta belongs to an airline.
   One family does everything; no sans-serif enters the system.
   ============================================================ */

:root {
  /* ---------- COLOUR: the four ---------- */
  --c-ink:      #201E1D;  /* the mark, all type, all rules */
  --c-cyan:     #0088B0;  /* interactive elements and callouts */
  --c-paper:    #F3F2F2;  /* the ground */
  --c-magenta:  #D6006C;  /* once a page at most. Never in the mark. */

  /* ---------- COLOUR: derived ink ---------- */
  --c-ink-70:   #55534F;  /* body copy */
  --c-ink-45:   #86837F;  /* captions, metadata, spec labels */
  --c-ink-25:   #B6B3AF;  /* placeholder, disabled */

  /* ---------- COLOUR: derived paper ---------- */
  --c-paper-raised: #FBFAFA; /* cards and panels lifted off the ground */
  --c-paper-sunk:   #E9E8E7; /* recessed bands, table headers */
  --c-cyan-tint:    #E6F1F6; /* clear-space and callout fills */
  --c-cyan-deep:    #006B8C; /* hover, and cyan on tint */

  /* ---------- COLOUR: rules ---------- */
  --c-rule:       #C7C4C0;  /* standard hairline */
  --c-rule-soft:  #DEDCD9;  /* secondary division */
  --c-rule-heavy: var(--c-ink); /* masthead and section openers */

  /* ---------- TYPE: one family ---------- */
  --f-serif: "Source Serif 4", "Source Serif Pro", "Iowan Old Style", Georgia, "Times New Roman", serif;

  /* Wordmark 600 / 0.11em · Headings 600 / -0.02em */
  --w-regular: 400;
  --w-medium:  500;
  --w-semi:    600;
  --w-bold:    700;

  /* ---------- TYPE SCALE ---------- */
  --fs-display: clamp(2.75rem, 6.2vw, 5.25rem);
  --fs-h1:      clamp(2.25rem, 4.4vw, 3.75rem);
  --fs-h2:      clamp(1.75rem, 2.8vw, 2.5rem);
  --fs-h3:      clamp(1.125rem, 1.5vw, 1.375rem);
  --fs-lead:    clamp(1.0625rem, 1.35vw, 1.25rem);
  --fs-body:    1.0625rem;
  --fs-sm:      0.9375rem;
  --fs-xs:      0.875rem;
  --fs-spec:    0.75rem;   /* spec labels — small caps, tracked */

  --lh-tight: 1.06;
  --lh-snug:  1.2;
  --lh-body:  1.62;

  --ls-wordmark: 0.11em;
  --ls-heading: -0.02em;
  --ls-spec:     0.14em;

  /* ---------- SPACE (4px base) ---------- */
  --s-1:  4px;  --s-2:  8px;  --s-3: 12px;  --s-4: 16px;
  --s-5: 24px;  --s-6: 32px;  --s-7: 48px;  --s-8: 64px;
  --s-9: 96px;  --s-10:128px; --s-11:160px; --s-12:224px;

  /* ---------- LAYOUT ---------- */
  --w-page:   1180px;
  --w-text:   66ch;
  --w-narrow: 780px;
  --gutter:   clamp(20px, 4.5vw, 56px);

  /* ---------- FORM ---------- */
  --r-none: 0;   /* the system has no curves */
  --bw:     1px;
  --bw-heavy: 2px;

  /* ---------- MOTION: a plate does not animate ---------- */
  --t-fast: 140ms;
  --t-base: 280ms;
  --t-reveal: 800ms;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);

  --z-content: 10; --z-nav: 100;
}

/* Reversed surface — for ink panels, title slides, apparel.
   On ink, the mark reverses to paper. */
[data-surface="ink"] {
  --c-paper:        #201E1D;
  --c-paper-raised: #2B2928;
  --c-paper-sunk:   #191716;
  --c-ink:          #F3F2F2;
  --c-ink-70:       #C2BFBB;
  --c-ink-45:       #8E8B87;
  --c-ink-25:       #5C5955;
  --c-rule:         #45423F;
  --c-rule-soft:    #34312F;
  --c-cyan:         #35AACF;
  --c-cyan-tint:    #24333A;
  --c-cyan-deep:    #6BC6E2;
}