:root {
  --bg: #f7f8fa;
  --surface: #ffffff;
  --text: #1b1f24;
  --muted: #5b6470;
  --border: #e2e6eb;
  --accent: #1f6feb;
  --accent-ink: #ffffff;
  --code-bg: #eef1f5;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e1116;
    --surface: #161b22;
    --text: #e6edf3;
    --muted: #9aa5b1;
    --border: #2a313b;
    --accent: #4c8dff;
    --accent-ink: #0e1116;
    --code-bg: #1f2630;
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 17px;
  line-height: 1.6;
}

a { color: var(--accent); }
a:hover { text-decoration-thickness: 2px; }

.wrap {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 16px;
}

header.site {
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}

header.site .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 64px;
}

.brand {
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: -0.01em;
  color: var(--text);
  text-decoration: none;
}

.brand span { color: var(--accent); }

nav a {
  color: var(--muted);
  text-decoration: none;
  margin-left: 20px;
  font-size: 0.95rem;
}

nav a:hover, nav a[aria-current="page"] { color: var(--text); }

main { padding: 48px 0 64px; }

.hero h1 {
  font-size: clamp(2rem, 5vw, 2.8rem);
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin: 0 0 12px;
}

.hero p.lede {
  font-size: 1.15rem;
  color: var(--muted);
  margin: 0 0 32px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  margin: 0 0 24px;
}

.card h2 { margin-top: 0; font-size: 1.3rem; }

.btn {
  display: inline-block;
  background: var(--accent);
  color: var(--accent-ink);
  padding: 10px 18px;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
}

.btn:hover { filter: brightness(1.08); }

.policy h1 { font-size: 2.1rem; line-height: 1.2; margin: 0 0 8px; letter-spacing: -0.02em; }
.policy h2 { font-size: 1.3rem; margin: 40px 0 8px; padding-top: 8px; border-top: 1px solid var(--border); }
.policy h3 { font-size: 1.05rem; margin: 24px 0 4px; }
.policy .meta { color: var(--muted); margin: 0 0 24px; }
.policy li { margin: 4px 0; }

.callout {
  border-left: 4px solid var(--accent);
  background: var(--surface);
  padding: 14px 18px;
  border-radius: 0 8px 8px 0;
  margin: 20px 0;
}

.toc { font-size: 0.95rem; }
.toc ol { margin: 8px 0 0; padding-left: 20px; }

code {
  background: var(--code-bg);
  padding: 1px 6px;
  border-radius: 4px;
  font-size: 0.9em;
  overflow-wrap: anywhere;
}

footer.site {
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.9rem;
  padding: 24px 0 40px;
}

footer.site a { color: var(--muted); }

@media (max-width: 480px) {
  nav a { margin-left: 14px; }
  main { padding-top: 32px; }
}