/* HTML: <div class="loader"></div> */
.loader {
    /*position: fixed;*/
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: #f7f9fb;
    transition: opacity 0.75s, visibility 0.75s;
}

.loader-hidden{
    opacity: 0;
    visibility: hidden;
    width: 0;
    height: 0;
}

.loader::after{
    content: "";
    width: 75px;
    height: 75px;
    border: 15px solid #dddddd;
    border-top-color: #00539b;
    border-radius: 50%;
    animation: loading 0.75s ease infinite;
}

@keyframes loading {
    from {
        transform: rotate(0turn);
    }
    to{
        transform: rotate(1turn);
    }
}


.reveal{
    position: relative;
    transform: translateY(150px);
    opacity: 0;
    transition: all 2s ease;
}

.reveal.active{
    transform: translateY(0px);
    opacity: 1;
}

.revealx{
    position: relative;
    transform: translateX(150px);
    opacity: 0;
    transition: all 2s ease;
}

.revealx.active{
    transform: translateX(0px);
    opacity: 1;
}

.revealmx{
    position: relative;
    transform: translateX(-100%);
    opacity: 0;
    transition: all 2s ease;
}

.revealmx.active{
    transform: translateX(0px);
    opacity: 1;
}

.booksreveal:nth-child(2){
    transition-delay: 200ms;
}
.booksreveal:nth-child(3){
    transition-delay: 400ms;
}
.booksreveal:nth-child(4){
    transition-delay: 600ms;
}