body {
  background: radial-gradient(circle at bottom, #0d1b2a, #000);
  color: #e0e0e0;
  font-family: 'Orbitron', sans-serif;
  text-align: center;
  margin: 0;
}

header {
  background: rgba(10, 20, 40, 0.8);
  padding: 15px;
  color: #4fc3f7;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 10px #4fc3f7;
}

.back-btn {
  position: absolute;
  left: 20px;
  color: #4fc3f7;
  text-decoration: none;
  font-size: 1.2em;
}

.panel {
  display: inline-block;
  background: rgba(20, 30, 50, 0.8);
  margin: 20px;
  padding: 25px;
  border-radius: 12px;
  box-shadow: 0 0 20px rgba(79, 195, 247, 0.4);
  width: 250px;
}