body {
  font-family: Arial, sans-serif;
  background: #0f0f0f;
  color: #fff;
  margin: 0;
}

header {
  text-align: center;
  padding: 80px 20px;
  background: linear-gradient(45deg, #000, #1a1a1a);
}

.btn {
  padding: 12px 24px;
  background: gold;
  color: #000;
  text-decoration: none;
  font-weight: bold;
}