html {
  scroll-behavior: smooth;
}

.book {
  perspective: 1200px;
}

.cover {
  transform-origin: left;
  transition: transform 0.8s ease-in-out;
  backface-visibility: visible;
}

.book.open .cover {
  transform: rotateY(-150deg);
}
#book {
  perspective: 1000px;
}

#book:hover {
  transform: rotateX(15deg) translateY(-1rem);
}

#book {
  transition: transform 0.5s ease;
  transform-style: preserve-3d;
}