:root {
  /* Typography */
  --font-sans: "Inter", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", "Cascadia Code", ui-monospace, "SF Mono", Menlo, Consolas, monospace;

  /* Colours — light */
  --bg:       #f6f8fa;
  --fg:       #0d1117;
  --muted:    #656d76;
  --accent:   #0969da;
  --accent-hover: #0550ae;
  --accent-subtle: #ddf4ff;
  --border:   #d0d7de;
  --card-bg:  #ffffff;
  --code-bg:  #f0f2f4;
  --surface:  #eaeef2;

  /* Layout */
  --max-wide: 1040px;
  --max:      680px;    /* comfortable prose reading width */

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(31, 35, 40, 0.06), 0 1px 2px rgba(31, 35, 40, 0.04);
  --shadow-md: 0 3px 12px rgba(31, 35, 40, 0.10), 0 1px 3px rgba(31, 35, 40, 0.06);
  --shadow-lg: 0 8px 24px rgba(31, 35, 40, 0.12);

  /* Motion */
  --t: 0.15s ease;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg:       #0d1117;
    --fg:       #e6edf3;
    --muted:    #8b949e;
    --accent:   #58a6ff;
    --accent-hover: #79b8ff;
    --accent-subtle: #121d2f;
    --border:   #30363d;
    --card-bg:  #161b22;
    --code-bg:  #1c2128;
    --surface:  #21262d;

    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 3px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
  }
}