body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: url('background.png') no-repeat center center fixed;
  background-size: cover;
  animation: pulse 10s infinite ease-in-out;
  color: #fff;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}


@keyframes pulse {
  0% { filter: brightness(1); }
  50% { filter: brightness(1.2); }
  100% { filter: brightness(1); }
}

.container {
  background: rgba(0, 0, 0, 0.6);
  padding: 40px;
  border-radius: 10px;
  text-align: center;
  box-shadow: 0 0 20px rgba(255, 255, 255, 0.2);
}