styles.css

.cube {
  width: 200px;
  height: 200px;
  position: relative;
  perspective: 1000px;
}

.side {
  position: absolute;
  width: 200px;
  height: 200px;
  opacity: 0.8;
}

.front {
  background-color: #ff0000;
  transform: translateZ(100px);
}

.back {
  background-color: #00ff00;
  transform: rotateY(180deg) translateZ(100px);
}

.right {
  background-color: #0000ff;
  transform: rotateY(90deg) translateZ(100px);
}

.left {
  background-color: #ffff00;
  transform: rotateY(-90deg) translateZ(100px);
}

.top {
  background-color: #ff00ff;
  transform: rotateX(90deg) translateZ(100px);
}

.bottom {
  background-color: #00ffff;
  transform: rotateX(-90deg) translateZ(100px);
}

.cube {
  animation: rotate 5s infinite linear;
}

@keyframes rotate {
  0% {
    transform: rotateX(0deg) rotateY(0deg);
  }
  100% {
    transform: rotateX(360deg) rotateY(360deg);
  }
}