body {
  display: flex;
}

.cube {
  margin: auto;
  font-size: 24px;
  height: 1em;
  width: 1em;
  color: #ffcb05;
  position: relative;
  transform: rotatex(30deg) rotatey(45deg);
  transform-style: preserve-3d;
  animation: cube-spin 1.5s infinite ease-in-out alternate;
}

.side {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  transform-style: preserve-3d;
}
.side::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  background-color: currentcolor;
  transform: translatez(0.5em);
  animation: cube-explode 1.5s infinite ease-in-out;
  opacity: 0.5;
}

.side:nth-child(1) {
  transform: rotatey(90deg);
}

.side:nth-child(2) {
  transform: rotatey(180deg);
}

.side:nth-child(3) {
  transform: rotatey(270deg);
}

.side:nth-child(4) {
  transform: rotatey(360deg);
}

.side:nth-child(5) {
  transform: rotatex(90deg);
}

.side:nth-child(6) {
  transform: rotatex(270deg);
}

@keyframes cube-spin {
  0% {
    transform: rotatex(30deg) rotatey(45deg);
  }
  100% {
    transform: rotatex(30deg) rotatey(405deg);
  }
}
@keyframes cube-explode {
  0% {
    transform: translatez(0.5em);
  }
  50% {
    transform: translatez(0.75em);
  }
  100% {
    transform: translatez(0.5em);
  }
}