div.espacio3D {
  width: 400px;
  height: 400px;
  margin: 3em auto 0 auto;
  border: 0px solid rgba(0,255,0,0.5);
  position: relative;
  perspective-origin: center -50%;
  perspective: 500px;
  transform: scale(0.80);
}

div.cubo3D {
  width: 100%;
  height: 100%;
  position: absolute;
  transform-style: preserve-3d;
  transform: translateZ(-50%);
  animation-name: gira;
  animation-duration: 5000ms;
  animation-iteration-count: infinite;
}

div.base {
  position: absolute;
  width: 200px;
  height: 200px;
  background-color: rgba(0,0,0,0.15);
  transform: translateX(100px) translateY(100px) rotateX(90deg) translateZ(-200px);
  box-shadow: 0 0 50px 100px rgba(0,0,0,0.15);
}
aside.cara {
  position: absolute;
 width: 100%;
  height: 100%;
  background-color: rgba(255,255,255,0.50);
  border: 1px solid rgba(45, 53, 62,0.75);
  color: #08f;
  font-size: 3em;
  text-align: center;
  line-height: 100%;
  box-shadow: 0px 0px 5px rgba(45, 53, 62,0.75);
}
aside.cara img {
  width: 100%;
  height: 100%;
  object-fit:contain;
}
aside.cara1 { /* Frente */
  transform: translateZ(200px);
}

aside.cara2 { /* Atrás */
  transform: rotateY(180deg) translateZ(200px);
}

aside.cara3 { /* Izquierda */
  transform: rotateY(-90deg) translateZ(200px);
}

aside.cara4 { /* derecha */
  transform: rotateY(90deg) translateZ(200px);
}

aside.cara5 { /* abajo */
  transform: rotateX(-90deg) translateZ(200px);
}

aside.cara6 { /* arriba */
  transform: rotateX(90deg) translateZ(200px);
}

@keyframes gira {
  0% {
    transform: translateZ(-200px) rotateY(0deg);
  }
  100% {
    transform: translateZ(-200px) rotateY(360deg);
  }
}