/* ──────────────────────────────────────────────────────────────────────────────
 * AllocLab UI v5 — Typography
 * UI 憲法 §2: Serif 限 H1/H2/AI headline；Sans/Mono 走 system stack；body ≥15px
 * ────────────────────────────────────────────────────────────────────────────── */

:root {
  --ff-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang TC",
    "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  --ff-display: "Noto Serif TC", "Source Han Serif TC", "PingFang TC", serif;
  --ff-mono: ui-monospace, "SFMono-Regular", "Cascadia Code", "JetBrains Mono",
    Consolas, monospace;

  /* Type scale (rem-based, 15px body baseline) */
  --fs-xs: 0.6875rem;   /* 11px */
  --fs-sm: 0.75rem;     /* 12px */
  --fs-base: 0.875rem;  /* 14px */
  --fs-md: 0.9375rem;   /* 15px */
  --fs-lg: 1rem;        /* 16px */
  --fs-xl: 1.125rem;    /* 18px */
  --fs-2xl: 1.375rem;   /* 22px */
  --fs-3xl: 1.75rem;    /* 28px */

  /* Line height */
  --lh-tight: 1.25;
  --lh-base: 1.5;
  --lh-relaxed: 1.65;
}

body {
  font-family: var(--ff-sans);
  font-size: var(--fs-base);
  line-height: var(--lh-base);
  letter-spacing: 0.005em;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  font-weight: 600;
  line-height: var(--lh-tight);
  color: var(--al-ink);
}

h1 {
  font-family: var(--ff-display);
  font-size: var(--fs-3xl);
}

h2 {
  font-family: var(--ff-display);
  font-size: var(--fs-2xl);
}

h3 {
  font-size: var(--fs-lg);
}

h4 {
  font-size: var(--fs-md);
}

code,
kbd,
.mono {
  font-family: var(--ff-mono);
  font-variant-numeric: tabular-nums;
}

p {
  margin: 0;
}