:root {
  color-scheme: light dark;
  --fg: #111;
  --muted: #555;
  --bg: #fafafa;
  --card: #fff;
  --line: #e4e4e4;
}

@media (prefers-color-scheme: dark) {
  :root {
    --fg: #f2f2f2;
    --muted: #a8a8a8;
    --bg: #111;
    --card: #1a1a1a;
    --line: #2c2c2c;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  color: var(--fg);
  background: var(--bg);
  line-height: 1.5;
}

main {
  max-width: 40rem;
  margin: 0 auto;
  padding: 4rem 1.5rem;
}

.center {
  text-align: center;
}

h1 {
  font-size: 2rem;
  margin: 0 0 0.75rem;
}

p {
  color: var(--muted);
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 1.5rem;
  margin-top: 2rem;
}

.button {
  display: inline-block;
  margin-top: 1rem;
  padding: 0.6rem 1.1rem;
  border-radius: 8px;
  background: var(--fg);
  color: var(--bg);
  text-decoration: none;
  font-weight: 600;
}

footer {
  margin-top: 3rem;
  font-size: 0.85rem;
  color: var(--muted);
}

footer a {
  color: inherit;
}