.book-container {
  display: flex;
  align-items: center;
  justify-content: center;
  perspective: 600px;
}

@keyframes initAnimation {
  0% {
    transform: rotateY(-11deg);
  }
  100% {
    transform: rotateY(-30deg);
  }
}

.book {
  width: 275px;
  height: 350px;
  position: relative;
  transform-style: preserve-3d;
  transform: rotateY(-30deg);
  transition: 1.5s ease;
  animation: 1s ease 0s 1 initAnimation;
}

.book:hover {
  transform: rotateY(-11deg);
}

.book > :first-child {
  position: absolute;
  top: 0;
  left: 0;
  background-color: red;
  width: 275px;
  height: 350px;
  transform: translateZ(45px);
  background-color: #01060f;
  border-radius: 0 3px 3px 0;
  box-shadow: 5px 5px 20px #666;
}

.book::before {
  position: absolute;
  content: ' ';
  background-color: blue;
  left: 0;
  top: 5px;
  width: 88px;
  height: 340px;
  transform: translateX(225px) rotateY(90deg);
  background: linear-gradient(90deg, 
    #fff 0%,
    #f9f9f9 5%,
    #fff 10%,
    #f9f9f9 15%,
    #fff 20%,
    #f9f9f9 25%,
    #fff 30%,
    #f9f9f9 35%,
    #fff 40%,
    #f9f9f9 45%,
    #fff 50%,
    #f9f9f9 55%,
    #fff 60%,
    #f9f9f9 65%,
    #fff 70%,
    #f9f9f9 75%,
    #fff 80%,
    #f9f9f9 85%,
    #fff 90%,
    #f9f9f9 95%,
    #fff 100%
    );
}

.book::after {
  position: absolute;
  top: 0;
  left: 0;
  content: ' ';
  width: 275px;
  height: 350px;
  transform: translateZ(-45px);
  background-color: #01060f;
  border-radius: 0 3px 3px 0;
  box-shadow: -10px 0 50px 10px #666;
}

/* Misc */

body {
  padding: 20vh 10vw;
}