body {
  font-family: system-ui, sans-serif;
  max-width: 720px;
  margin: 60px auto;
  padding: 0 20px;
  color: #222;
  background: #f5f7fa;
  text-align: center;
}

main {
  padding: 32px;
  background: white;
  border-radius: 12px;
}

button {
  display: block;
  margin: 20px auto;
  padding: 10px 16px;
  cursor: pointer;
}