body {
  font-family: "Microsoft YaHei", sans-serif;
  background: linear-gradient(to right, #74ebd5, #ACB6E5);
  margin: 0;
  padding: 0;
  text-align: center;
}

header {
  background: rgba(0,0,0,0.6);
  color: #fff;
  padding: 20px;
}

main {
  padding: 40px;
}

button {
  padding: 10px 20px;
  border: none;
  border-radius: 8px;
  background: #007bff;
  color: white;
  cursor: pointer;
  font-size: 16px;
}

button:hover {
  background: #0056b3;
}