/* tesaurex.com — Columbia Canvas design tokens
   ─────────────────────────────────────────────────────────────────────
   One controlled light brand presentation. The site does NOT switch to a
   dark scheme when macOS is in Dark Mode: `color-scheme: light` is
   declared on :root and no prefers-color-scheme: dark block repaints the
   page. Dark surfaces appear only where the product itself is dark —
   inside the Project Tesoro island.

   ACCESSIBILITY DERIVATION OF AZURE
   Brand Azure #0080FE is the accent. Measured against this palette:
     white on #0080FE ................ 3.85 : 1   (fails AA body text)
     #0080FE on Columbia Blue ........ 2.61 : 1   (fails AA body text)
   So Azure is used at full strength only where contrast is not a text
   requirement (mark, focus ring, rules, visualizer, indicators), and two
   same-family derivations carry text:
     --azure-deep #0066D2  button fill, white label ....... 5.51 : 1  AA
     --azure-ink  #005AB4  link text on Columbia Blue ..... 4.70 : 1  AA
                           link text on white ............. 6.92 : 1  AAA
*/

:root {
  color-scheme: light;

  /* ---- Brand ---- */
  --azure: #0080fe;          /* binding primary accent */
  --azure-deep: #0066d2;     /* AA button fill */
  --azure-deeper: #0055b0;   /* button hover */
  --azure-ink: #005ab4;      /* AA link text */
  --azure-wash: #e8f2fd;     /* faintest azure tint */

  /* ---- Canvas ---- */
  --columbia: #c4d8e1;       /* binding main website background */
  --columbia-deep: #aec8d5;  /* subtle darker variant */
  --columbia-soft: #d7e6ed;  /* lifted variant */
  --blue-white: #eef5f8;     /* very light blue-white */
  --cool-white: #f7fafb;     /* soft cool white */
  --white: #ffffff;

  /* ---- Ink ---- */
  --ink: #0b1116;            /* near-black text */
  --ink-2: #3d4d59;          /* restrained medium gray, 6.6:1 on columbia */
  --ink-3: #4a5a66;          /* lightest permitted gray, 4.99:1 on columbia */

  /* ---- Lines ---- */
  --line: rgba(11, 17, 22, 0.14);
  --line-soft: rgba(11, 17, 22, 0.08);
  --line-strong: rgba(11, 17, 22, 0.24);

  /* ---- Elevation ---- */
  --shadow-sm: 0 1px 2px rgba(11, 17, 22, 0.06),
               0 2px 6px rgba(11, 17, 22, 0.05);
  --shadow-md: 0 2px 4px rgba(11, 17, 22, 0.05),
               0 10px 26px rgba(11, 17, 22, 0.09);
  --shadow-lg: 0 4px 10px rgba(11, 17, 22, 0.06),
               0 26px 60px rgba(11, 17, 22, 0.13);

  /* ---- Type ---- */
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display",
          "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-display: -apple-system, BlinkMacSystemFont, "SF Pro Display",
          "SF Pro Text", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;

  /* Fluid display sizes — one scale for the whole site. */
  --t-display: clamp(2.30rem, 1.28rem + 3.02vw, 3.95rem);
  --t-h2:      clamp(1.72rem, 1.20rem + 1.52vw, 2.60rem);
  --t-h3:      clamp(1.10rem, 1.01rem + 0.28vw, 1.30rem);
  --t-lede:    clamp(1.04rem, 0.98rem + 0.21vw, 1.20rem);
  --t-body:    1rem;
  --t-small:   0.905rem;
  --t-micro:   0.80rem;

  /* ---- One layout grid for every page ---- */
  --page-max: 1240px;
  --gutter: clamp(1.25rem, 0.85rem + 1.9vw, 2.75rem);

  /* ---- Predictable vertical rhythm ---- */
  --band: clamp(3.6rem, 2.5rem + 3.4vw, 6.25rem);
  --band-tight: clamp(2.5rem, 1.85rem + 2.1vw, 4.1rem);

  /* ---- Radii — used sparingly, never on every section ---- */
  --r-stage: 26px;
  --r-media: 18px;
  --r-pill: 999px;
  --r-sm: 10px;

  --focus-ring: 0 0 0 3px var(--white), 0 0 0 6px var(--azure);
}

/* macOS Dark Mode must not repaint the canvas. The scheme hint is
   restated so native form controls and scrollbars stay light as well. */
@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: light;
  }
}