body {
  font-family: system-ui, sans-serif;
  background: #f7f7f7;
  margin: 0;
}

main {
  max-width: 600px;
  margin: 10vh auto;
  background: white;
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.1);
  text-align: center;
}

a {
  display: inline-block;
  margin-top: 1rem;
  text-decoration: none;
  color: white;
  background: black;
  padding: 0.6rem 1.2rem;
  border-radius: 8px;
}