:root {
  color-scheme: dark;
  --bg: #0f172a;
  --panel: #111c33;
  --text: #e8eef8;
  --muted: #94a3b8;
  --accent: #60a5fa;
  --rule: #1e2f4d;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 32px 20px 72px;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  font-size: 17px;
  line-height: 1.65;
}

main {
  max-width: 720px;
  margin: 0 auto;
}

.back {
  margin: 0 0 24px;
  font-size: 15px;
}

.back a {
  color: var(--muted);
  text-decoration: none;
}

.back a:hover { color: var(--accent); }

h1 {
  margin: 0 0 4px;
  font-size: 30px;
  line-height: 1.25;
}

h2 {
  margin: 36px 0 10px;
  padding-top: 20px;
  border-top: 1px solid var(--rule);
  font-size: 19px;
  line-height: 1.35;
}

.updated {
  margin: 0 0 28px;
  color: var(--muted);
  font-size: 15px;
}

ul { padding-left: 22px; }

li { margin-bottom: 10px; }

a { color: var(--accent); }

strong { color: #fff; }

.callout {
  margin: 24px 0;
  padding: 16px 18px;
  border: 1px solid var(--rule);
  border-radius: 10px;
  background: var(--panel);
}

.callout p:first-child { margin-top: 0; }
.callout p:last-child { margin-bottom: 0; }

@media (prefers-color-scheme: light) {
  :root {
    color-scheme: light;
    --bg: #ffffff;
    --panel: #f6f8fc;
    --text: #16202f;
    --muted: #5b6b82;
    --accent: #1d4ed8;
    --rule: #e2e8f0;
  }
  strong { color: #000; }
}