body, html {
  height: 100%;
}

.falling-leaves {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 100%;
  transform: translate(-50%, 0);
  background-color: rgba(0, 0, 0, 0.2);
  /*background-size: cover;*/
  overflow: hidden;
}

.leaf-scene {
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  width: 100%;
  transform-style: preserve-3d;
}
.leaf-scene div {
  position: absolute;
  top: 0;
  left: 0;
  width: 20px;
  height: 20px;
  background: url("hoja.png") no-repeat;
  background-size: 100%;
  transform-style: preserve-3d;
  -webkit-backface-visibility: visible;
          backface-visibility: visible;
}