.gallery {
    column-count: 3;
    column-gap: 15px;
}
.gallery img {
    width: 100%;
    border-radius: 10px;
    margin-bottom: 15px;
    display: block;
}
@media (max-width: 768px) {
    .gallery {
        column-count: 2;
    }
}
@media (max-width: 576px) {
    .gallery {
        column-count: 1;
    }
}