.overlay-box{
    display: block;
    position: absolute;
    overflow-x: hidden;
    overflow-y: hidden;
    z-index: 2;
    float: left;
    -webkit-transition: opacity 0.4s ease-in-out;
    -moz-transition: opacity 0.4s ease-in-out;
    -o-transition: opacity 0.4s ease-in-out;
    transition: opacity 0.4s ease-in-out;
    height: 0;
}

.overlay-box.unfolded{
    height: fit-content;
}