body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #f7f7f7;
  color: #222;
}
main {
  max-width: 720px;
  margin: 12vh auto;
  padding: 32px;
  background: white;
  border-radius: 12px;
}
.muted {
  color: #666;
}