body {
  margin: 0;
  padding: 0;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background: linear-gradient(135deg, #0a0a0a, #1a1a1a);
  font-family: 'Orbitron', sans-serif;
  color: #00ffcc;
  overflow: hidden;
}

.container {
  text-align: center;
  padding: 2rem;
  background: rgba(0, 0, 0, 0.8);
  border-radius: 15px;
  box-shadow: 0 0 20px rgba(0, 255, 204, 0.5);
  animation: fadeIn 1s ease-in-out;
}

h1 {
  font-size: 2.5rem;
  text-shadow: 0 0 10px #00ffcc;
  margin-bottom: 1.5rem;
}

.generate-button {
  padding: 1rem 2rem;
  font-size: 1.2rem;
  font-family: 'Orbitron', sans-serif;
  background: linear-gradient(45deg, #00ffcc, #00ccff);
  border: none;
  border-radius: 10px;
  color: #000;
  cursor: pointer;
  transition: transform 0.3s, box-shadow 0.3s;
  box-shadow: 0 0 15px rgba(0, 255, 204, 0.7);
}

.generate-button:hover {
  transform: scale(1.05);
  box-shadow: 0 0 25px rgba(0, 255, 204, 1);
}

.key-display {
  margin: 1.5rem 0;
  padding: 1rem;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 10px;
  font-size: 1.2rem;
  min-height: 2rem;
  text-shadow: 0 0 5px #00ffcc;
  word-break: break-all;
}

.notification {
  margin: 1rem 0;
  padding: 1rem;
  background: rgba(255, 50, 50, 0.2);
  border: 2px solid #ff3333;
  border-radius: 10px;
  font-size: 1rem;
  color: #ff9999;
  text-shadow: 0 0 5px #ff3333;
  opacity: 0;
  transform: translateY(-10px);
  transition: opacity 0.5s, transform 0.5s;
}

.notification.show {
  opacity: 1;
  transform: translateY(0);
}

.notification.hidden {
  display: none;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes pulse {
  0% { box-shadow: 0 0 10px rgba(0, 255, 204, 0.5); }
  50% { box-shadow: 0 0 20px rgba(0, 255, 204, 1); }
  100% { box-shadow: 0 0 10px rgba(0, 255, 204, 0.5); }
}

.container::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle, rgba(0, 255, 204, 0.1), transparent);
  z-index: -1;
  animation: pulse 5s infinite;
}