.gallery2 {
    display: grid ;
    grid-template-columns: repeat(auto-fit,minmax(100px,1fr)) ;
    grid-auto-rows: 100px ;
    grid-auto-flow: dense ;
    gap: 2px ;
}

.gallery2 >div img {
        width: 100% ;
        height: 100% ;
    }
    .gallery2 > div a {
        width: 100% ;
        height: 100% ;
    }
.vertical {
    grid-row: auto/span 2;
}
.horizental {

    grid-column: auto/span 2;
}
.big {

    grid-row: auto/span 2;
    grid-column: auto/span 2;
}