div#flipbook {
    transform: rotateZ(30deg);
}

div#flipbook div.turn-page {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    background-size: 100% 100%;
    background-image: url("/images/sketchbook-paper.png");
}

div#flipbook div.turn-page.hard.front {
    background-image: url("/images/sketchbook-front.png");
}
div#flipbook div.turn-page.hard {
    background-image: url("/images/sketchbook-cover.png");
}

div#flipbook img {
    max-width: 80%;
    max-height: 80%;
    transition: transform 250ms;
}

div#flipbook img:hover {
    transform: scale(1.1);
}