/* Design tokens (owner: Designer). Text-only site: colour and type only.
   Palette: the bridge's own paint and stone.
   - Bridge blue (the girders, repainted blue/white/red in 2012) is the accent.
   - Warm Portland-stone paper is the background.
   - Signal red is a sparing second accent (rules, highlights).
   Contrast on --color-bg (#f6f3ec): text 15:1, muted 7:1, accent 10:1, red 7:1 (all AA/AAA). */
:root {
  /* Colour */
  --color-bg: #f6f3ec;
  --color-surface: #ebe6da;
  --color-text: #17202b;
  --color-muted: #4a5461;
  --color-accent: #0a3a6e;
  --color-accent-strong: #062a52;
  --color-highlight: #9b1c24;
  --color-rule: #b9b1a0;
  --color-focus: #0a3a6e;

  /* Type: serif headings (Georgia, a stately Victorian feel), system sans body */
  --font-body: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-heading: Georgia, "Times New Roman", serif;
  --font-mono: ui-monospace, "SF Mono", Consolas, monospace;

  /* Type scale (ratio ~1.25) */
  --text-sm: 0.875rem;
  --text-base: 1.0625rem;
  --text-lg: 1.25rem;
  --text-xl: 1.5625rem;
  --text-2xl: 1.953rem;
  --text-3xl: 2.441rem;
  --text-4xl: clamp(2.5rem, 6vw, 3.815rem);
  --leading-tight: 1.15;
  --leading-body: 1.65;
  --measure: 66ch;
  --tracking-caps: 0.08em;

  /* Spacing and shape */
  --space: 1rem;
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 2rem;
  --space-xl: 4rem;
  --radius: 2px;
  --rule-width: 3px;
}