:root {
  color-scheme: light dark;
  --bg: #f5f7fa;
  --fg: #1b2330;
  --accent: #0b6bcb;
  --card: #ffffff;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #12161d;
    --fg: #e6ebf2;
    --accent: #5aa9ff;
    --card: #1b212b;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.6;
}

main {
  max-width: 44rem;
  margin: 3rem auto;
  padding: 2rem;
  background: var(--card);
  border-radius: 12px;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
}

h1 {
  margin-top: 0;
  color: var(--accent);
}

.lead {
  font-size: 1.1rem;
}

ol {
  padding-left: 1.25rem;
}

li {
  margin-bottom: 0.75rem;
}

footer {
  margin-top: 2rem;
  font-size: 0.9rem;
  opacity: 0.75;
}