html, body {
  margin: 0;
  height: 100%;
  width: 100%;
  background: radial-gradient(circle at center, #000010, #000000);
  overflow: hidden;
  display: flex;
  justify-content: center;
  align-items: center;
}

#space {
  position: relative;
  width: 100%;
  height: 100%;
}

#planet {
  width: 200px;
  height: 200px;
  border-radius: 50%;
  background-color: #888;
  background-size: cover;
  animation: rotatePlanet 10s linear infinite;
  margin: auto;
}

@keyframes rotatePlanet {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

#textureLoader {
  position: absolute;
  top: 10px;
  left: 10px;
  z-index: 10;
  background: rgba(255,255,255,0.1);
  color: #fff;
  border: 1px solid #fff;
  padding: 5px;
  cursor: pointer;
}