#book {
  position: relative;
  padding-top: 100%;
}

#book > canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: none !important;
  outline: none !important;
  pointer-events: none;
  opacity: 0;
  transition: opacity .3s ease-in;
}

#book > img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  max-width: none;
  max-height: none;
  border: none !important;
  outline: none !important;
  pointer-events: none;
  opacity: 1;
  transition: opacity .3s ease-in;
}

@media (max-width: 750px) {
  #book {
    padding-top: 120%;
  }

  #book > canvas,
  #book > img {
    left: -10%;
    width: 120%;
    height: 100%;
    max-width: 120%;
  }
}