body {
  background: radial-gradient(circle, #000010, #000);
  color: #0ff;
  font-family: 'Orbitron', sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  flex-direction: column;
}

.center-box {
  text-align: center;
  background: rgba(0, 0, 20, 0.8);
  padding: 30px;
  border-radius: 20px;
  box-shadow: 0 0 25px #0ff;
}

.btn {
  display: inline-block;
  margin-top: 20px;
  padding: 12px 25px;
  background: #0ff;
  color: #000;
  border-radius: 10px;
  font-weight: bold;
  text-decoration: none;
  transition: 0.3s;
}

.btn:hover {
  background: #00cccc;
  box-shadow: 0 0 20px #0ff;
}