body, html {
  margin: 0;
  padding: 0;
  overflow: hidden;
  height: 100%;
  font-family: 'Orbitron', sans-serif;
  color: white;
  text-align: center;
  background: black;
}

#background {
  position: absolute;
  width: 100%;
  height: 100%;
  overflow: hidden;
  z-index: 0;
}

.stars, .stars2, .earth {
  position: absolute;
  width: 100%;
  height: 100%;
  background-repeat: no-repeat;
  background-size: cover;
  background-position: center;
}

.stars {
  background-image: url('stars.jpg');
  animation: twinkle 1.5s infinite alternate;
}

.stars2 {
  background-image: url('stars2.jpg');
  opacity: 0.4;
}

.earth {
  background-image: url('earth.jpg');
  z-index: 1;
  animation: rotateEarth 240s linear infinite; /* 4-minute rotation loop */
  transform-origin: center center;
  background-size: cover;
  background-position: center;
}

/* Rotation animation */
@keyframes rotateEarth {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}


#content {
  position: relative;
  z-index: 2;
  top: 40%;
}

@keyframes twinkle {
  from { opacity: 0.5; }
  to { opacity: 1; }
}