/* =============================================================================
   Digital Atrium — Design Tokens
   Single source of color, type, radius, and elevation for the whole site.
   Palette: terracotta primary, stone tertiary, warm parchment surfaces.
   ============================================================================= */

:root {
  /* --- Color: primary (fired clay) --- */
  --color-primary: #87361d;
  --color-primary-container: #a64d32;
  --color-primary-fixed: #ffdbd1;
  --color-primary-fixed-dim: #ffb59f;
  --color-on-primary: #ffffff;
  --color-on-primary-container: #ffe0d8;
  --color-on-primary-fixed: #3a0a00;
  --color-on-primary-fixed-variant: #7c2e15;
  --color-inverse-primary: #ffb59f;
  --color-surface-tint: #9a442a;

  /* --- Color: secondary (cool portico) --- */
  --color-secondary: #5c5d6c;
  --color-secondary-container: #dedeef;
  --color-secondary-fixed: #e1e1f2;
  --color-secondary-fixed-dim: #c5c5d6;
  --color-on-secondary: #ffffff;
  --color-on-secondary-container: #606270;
  --color-on-secondary-fixed: #191b27;
  --color-on-secondary-fixed-variant: #444653;

  /* --- Color: tertiary (stone) --- */
  --color-tertiary: #574f3e;
  --color-tertiary-container: #6f6754;
  --color-tertiary-fixed: #ede1ca;
  --color-tertiary-fixed-dim: #d1c5af;
  --color-on-tertiary: #ffffff;
  --color-on-tertiary-container: #f2e6cf;
  --color-on-tertiary-fixed: #211b0d;
  --color-on-tertiary-fixed-variant: #4d4635;

  /* --- Color: surfaces (rooms, not lines) --- */
  --color-background: #fcf9f4;
  --color-on-background: #1c1c19;
  --color-surface: #fcf9f4;
  --color-surface-bright: #fcf9f4;
  --color-surface-dim: #dcdad5;
  --color-surface-variant: #e5e2dd;
  --color-surface-container-lowest: #ffffff;
  --color-surface-container-low: #f6f3ee;
  --color-surface-container: #f0ede8;
  --color-surface-container-high: #ebe8e3;
  --color-surface-container-highest: #e5e2dd;
  --color-on-surface: #1c1c19;
  --color-on-surface-variant: #55423d;
  --color-inverse-surface: #31302d;
  --color-inverse-on-surface: #f3f0eb;

  /* --- Color: outline (ghost only, never as section walls) --- */
  --color-outline: #88726c;
  --color-outline-variant: #dcc1ba;
  --color-ghost-border: color-mix(in srgb, var(--color-outline-variant) 15%, transparent);

  /* --- Color: error --- */
  --color-error: #ba1a1a;
  --color-error-container: #ffdad6;
  --color-on-error: #ffffff;
  --color-on-error-container: #93000a;

  /* --- Typography --- */
  --font-headline: "Newsreader", "Iowan Old Style", "Palatino Linotype", serif;
  --font-display: "Newsreader", "Iowan Old Style", "Palatino Linotype", serif;
  --font-body: "Manrope", "Segoe UI", sans-serif;
  --font-label: "Manrope", "Segoe UI", sans-serif;

  /* --- Density: Compact (2) --- */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-14: 3.5rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --gutter: 1.5rem;
  --gutter-lg: 4rem;
  --measure: min(96rem, 94vw);
  --measure-narrow: min(72rem, 90vw);
  --measure-copy: min(80rem, 92vw);

  /* --- Roundedness: Subtle (1) — carved stone, never pills --- */
  --radius: 0.125rem;
  --radius-lg: 0.25rem;
  --radius-xl: 0.5rem;

  /* --- Elevation: tonal layering + ambient terracotta glow --- */
  --shadow-ambient: 0 16px 40px color-mix(in srgb, var(--color-primary) 5%, transparent);
  --shadow-header: 0 1px 8px color-mix(in srgb, var(--color-on-surface) 4%, transparent);
  --shadow-btn: inset 0 1px 0 color-mix(in srgb, var(--color-on-primary) 12%, transparent), inset 0 -2px 4px color-mix(in srgb, #000 14%, transparent), 0 2px 8px color-mix(in srgb, var(--color-primary) 28%, transparent);
  --shadow-btn-hover: inset 0 1px 0 color-mix(in srgb, var(--color-on-primary) 10%, transparent), inset 0 -2px 4px color-mix(in srgb, #000 12%, transparent), 0 4px 12px color-mix(in srgb, var(--color-primary) 34%, transparent);

  /* --- Motion --- */
  --ease: 200ms ease;
  --header-height: 5rem;
  --landing-bar-height: 3.25rem;
  /* --- Glass rule (frosted marble) --- */
  --glass-surface: color-mix(in srgb, var(--color-surface) 80%, transparent);
  --glass-blur: 20px;

  /* --- Color: nocturnal (homepage atrium field only) --- */
  --color-nocturnal: #161310;
  --color-nocturnal-elevated: #1f1b17;
  --color-nocturnal-deep: #100e0c;

  /* --- Fired-clay CTA gradient --- */
  --gradient-tessera: linear-gradient(180deg, #b85a3c 0%, var(--color-primary-container) 48%, var(--color-primary) 100%);

  /* --- Hub field aliases (ITER 1): ceramic + parchment on nocturnal --- */
  --color-ceramic: #a64d32;
  --color-ceramic-bright: #b85a3c;
  --color-ceramic-light: #c46a4c; /* >=4.5:1 on nocturnal-elevated */
  --color-parchment: #fcf9f4;
  --color-nocturnal-lift: #27221d;
  --color-on-nocturnal: var(--color-parchment);
  --color-on-nocturnal-muted: color-mix(in srgb, var(--color-parchment) 66%, var(--color-nocturnal));
}