.loader {
  width: 30px;
  height: 30px;
  border: 2px solid aqua;
  box-shadow:
    0 0 8px aqua,
    0 0 8px aqua inset;
  border-radius: 5px;
  animation: 2s loading ease-in-out infinite;
}
@keyframes loading {
  0% {
    transform: rotateX(0) rotateY(0) rotateZ(0);
  }
  33% {
    transform: rotateX(180deg) rotateY(0) rotateZ(0);
  }
  67% {
    transform: rotateX(180deg) rotateY(180deg) rotateZ(0);
  }
  100% {
    transform: rotateX(180deg) rotateY(180deg) rotateZ(180deg);
  }
}