html, body {
    height: 100%;
}

.book-box {
    width: 100%;
    height: 100%;
}

.book-img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.flipbook-viewport {
    display: flex;
}

.flipbook-box {
    display: flex;
    align-items: center;
}

.flipbook .even .box-shadow {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: -webkit-gradient(linear, left top, right top, color-stop(0.95, rgba(0, 0, 0, 0)), color-stop(1, rgba(0, 0, 0, 0.2)));
    background-image: -webkit-linear-gradient(left, rgba(0, 0, 0, 0) 95%, rgba(0, 0, 0, 0.2) 100%);
    background-image: -moz-linear-gradient(left, rgba(0, 0, 0, 0) 95%, rgba(0, 0, 0, 0.2) 100%);
    background-image: -ms-linear-gradient(left, rgba(0, 0, 0, 0) 95%, rgba(0, 0, 0, 0.2) 100%);
    background-image: -o-linear-gradient(left, rgba(0, 0, 0, 0) 95%, rgba(0, 0, 0, 0.2) 100%);
    background-image: linear-gradient(left, rgba(0, 0, 0, 0) 95%, rgba(0, 0, 0, 0.2) 100%);
}

.flipbook .odd .box-shadow {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: -webkit-gradient(linear, right top, left top, color-stop(0.95, rgba(0, 0, 0, 0)), color-stop(1, rgba(0, 0, 0, 0.15)));
    background-image: -webkit-linear-gradient(right, rgba(0, 0, 0, 0) 95%, rgba(0, 0, 0, 0.15) 100%);
    background-image: -moz-linear-gradient(right, rgba(0, 0, 0, 0) 95%, rgba(0, 0, 0, 0.15) 100%);
    background-image: -ms-linear-gradient(right, rgba(0, 0, 0, 0) 95%, rgba(0, 0, 0, 0.15) 100%);
    background-image: -o-linear-gradient(right, rgba(0, 0, 0, 0) 95%, rgba(0, 0, 0, 0.15) 100%);
    background-image: linear-gradient(right, rgba(0, 0, 0, 0) 95%, rgba(0, 0, 0, 0.15) 100%);
}

.flipbook-viewport .page {
    pointer-events: none;
}

.previous-button {
    position: absolute;
    width: 27px;
    height: 44px;
    left: 10px;
    top: 50%;
    margin-top: -22px;
    cursor: pointer;
}

.next-button {
    position: absolute;
    width: 27px;
    height: 44px;
    right: 10px;
    top: 50%;
    margin-top: -22px;
    cursor: pointer;
}

.page-box {
    display: flex;
    position: absolute;
    right: 25px;
    bottom: 20px;
    font-size: 20px;
    align-items: center;
}

#currentPage {
    width: 70px;
    text-align: center;
    height: 28px;
    line-height: 1px;
    outline: none;
    vertical-align: middle;
    font-size: 100%;
    padding: 0;
    overflow: visible;
    box-sizing: border-box;
}

.line {
    width: 20px;
    text-align: center;
    padding-bottom: 2px;
}