.falling-leaves {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 100vw;
  max-width: 100vw;
  max-height: 100vh; // image is only 880x880
  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(egg.svg) no-repeat;
      background-size: 100%;
      transform-style: preserve-3d;
      backface-visibility: visible;
    }