.gallery{
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-auto-flow: dense;
}
.gallery > img{
    width: 100%;
    object-fit: cover;
}
.gallery > .img-1x1 {
    grid-column-end: span 1;
    grid-row-end: span 1;
    aspect-ratio: 1 / 1;
}

.gallery > .img-2x2 {
    grid-column-end: span 2;
    grid-row-end: span 2;
    aspect-ratio: 1 / 1;
}

.gallery > .img-2x1 {
    grid-column-end: span 2;
    grid-row-end: span 1;
    aspect-ratio: 2 / 1;
}