:root {
  /* Colour palette — warm, premium, book-like */
  --color-bg: #f7f4ee;
  --color-surface: #fffcf7;
  --color-text: #1a1814;
  --color-text-muted: #575349;
  --color-text-subtle: #7a7368;
  --color-accent: #2d4a52;
  --color-accent-hover: #1f363d;
  --color-accent-soft: #ebe4d6;
  --color-highlight: #5c4f3a;
  --color-border: #ddd6c8;
  --color-border-strong: #c9bfae;
  --color-focus: #2d4a52;

  /* Typography */
  --font-serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, "Cascadia Code", "Source Code Pro", Menlo, Consolas, monospace;

  --text-xs: 0.8125rem;
  --text-sm: 0.9375rem;
  --text-base: 1.125rem;
  --text-lg: 1.3125rem;
  --text-xl: 1.5625rem;
  --text-2xl: 2rem;
  --text-3xl: 2.5rem;

  --leading-tight: 1.22;
  --leading-normal: 1.7;
  --leading-relaxed: 1.78;

  /* Layout */
  --max-width-prose: 42rem;
  --max-width-wide: 56rem;
  --max-width-full: 72rem;
  --space-xs: 0.5rem;
  --space-sm: 0.75rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4.5rem;
  --header-height: 4rem;
  --radius-sm: 4px;
  --radius-md: 6px;
  --shadow-sm: 0 1px 2px rgba(26, 24, 20, 0.05);
  --shadow-md: 0 3px 10px rgba(26, 24, 20, 0.07);

  /* Breakpoints (reference) */
  --bp-sm: 36rem;
  --bp-md: 48rem;
  --bp-lg: 64rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #141312;
    --color-surface: #1f1d1a;
    --color-text: #edeae4;
    --color-text-muted: #b5aea3;
    --color-text-subtle: #8a837a;
    --color-accent: #7aabb8;
    --color-accent-hover: #94c0cb;
    --color-accent-soft: #2a2620;
    --color-highlight: #c4b08a;
    --color-border: #3a3630;
    --color-border-strong: #4d4840;
    --color-focus: #94c0cb;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.25);
    --shadow-md: 0 3px 10px rgba(0, 0, 0, 0.35);
  }
}