body {
  font-family: Arial, sans-serif;
  text-align: center;
  background-color: #f5f5f5;
  margin: 0;
  padding: 20px;
}

.bookshelf {
  display: flex;
  justify-content: flex-start;
  align-items: center;
  flex-direction: column;
  padding: 10px;
}

.book {
  margin: 10px;
  cursor: pointer;
}
.book img {
  width: 100px;
  height: 150px;
}

.book:hover {
  transform: rotateY(calc(var(--i) * 20deg)) translateZ(70px);
}