:root {
  color-scheme: light dark;
  --bg: #0d1117;
  --card: #161b22;
  --fg: #e6edf3;
  --muted: #9da7b3;
  --accent: #78d9ff;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: radial-gradient(circle at top, #1f2937, var(--bg) 60%);
  color: var(--fg);
}

.shell {
  max-width: 1100px;
  margin: 0 auto;
  padding: 40px 20px 80px;
}

.hero {
  margin-bottom: 24px;
}

.grid {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.card {
  background: color-mix(in srgb, var(--card) 90%, black 10%);
  border: 1px solid color-mix(in srgb, var(--card) 70%, white 30%);
  border-radius: 18px;
  padding: 20px;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.22);
}

.card h2 {
  margin-top: 0;
  color: var(--accent);
}