body {
  font-family: system-ui, sans-serif;
  background: #f8fafc;
  color: #1e293b;
  margin: 0;
  line-height: 1.6;
}
header {
  background: #1e293b;
  color: white;
  padding: 1rem 2rem;
}
header h1 { margin: 0; font-size: 1.5rem; }
nav {
  background: #334155;
  padding: 0.5rem 2rem;
}
nav a {
  color: white;
  margin-right: 1rem;
  text-decoration: none;
}
nav a:hover { text-decoration: underline; }
main { max-width: 800px; margin: 2rem auto; padding: 0 1rem; }
footer {
  text-align: center;
  font-size: 0.9rem;
  color: #64748b;
  margin: 4rem 0 1rem;
}