img.book {
  --a: -3deg; /* control the angle of rotation (the smaller, the better) */
  transform: perspective(400px) rotate3d(var(--r,1,-1),0,calc(var(--i,1)*var(--a)));
  -webkit-mask: 
    linear-gradient(135deg,#000c 40%,#000,#000c 60%)
    100% 100%/250% 250%;
  transition: .4s;
  cursor: pointer;
}
img.book:hover {
  --i: -1;
  -webkit-mask-position: 0 0;
}