body {
  font-family: system-ui, -apple-system, sans-serif;
  margin: 0;
  padding: 0;
  background: #f7f7f8;
  color: #222;
}

header {
  background: #2b2d42;
  color: white;
  padding: 1.5rem 2rem;
}

main {
  max-width: 600px;
  margin: 2rem auto;
  padding: 1rem 2rem;
  background: white;
  border-radius: 8px;
  box-shadow: 0 1px 4px rgba(0,0,0,0.1);
}

button {
  background: #2b2d42;
  color: white;
  border: none;
  padding: 0.6rem 1.2rem;
  border-radius: 6px;
  cursor: pointer;
  font-size: 1rem;
}

button:hover {
  background: #1f2033;
}