#book-tags {
    position: absolute;
    width: 2vw;
    top: 0px;
    z-index: var(--layer_pageTage);
    font-weight: bold;
    background-color: #006dd9;
}

.book-tag {
    width: 2vw;
    height: fit-content;
    min-height: 8vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    writing-mode: vertical-lr;
    letter-spacing: 5px;
    color: #040509;
    cursor: pointer;
    padding: 4px;
    box-sizing: border-box;
}

#book-tags.left {
    left: 0px;
    transform: translateX(0);
    transition: 0.5s;
    font-size: 2vh;
}

#book-tags.right {
    right: 0px;
    transform: translateX(0);
    transition: 0.5s;
    font-size: 2vh;
}

#book-tags.left.hide {
    transform: translateX(-100%);

}

#book-tags.right.hide {
    transform: translateX(100%);

}