.gallery.flex {
    display: block;
    overflow: auto;
    width: auto;
    white-space: nowrap;
}

.gallery-item {
    display: block !important;
    margin-top: 1em;
}

.gallery-item:first-of-type {
    margin-top: 0; 
}

.overlay > .previous,
.overlay > .next {
    display: none;
}