.masonry-container{
    -webkit-column-count: 3;
    -moz-column-count: 3;
    column-count: 3;
    margin: 1.5em;
    -moz-column-gap: 1.5em;
    -webkit-column-gap: 1.5em;
    column-gap: 1.5em;
}
.masonry-item{
    display: inline-block;
    margin: 0 0 1.5em;
    width: 100%;
    box-sizing: border-box;
    -moz-box-sizing: border-box;
    -webkit-box-sizing: border-box;
}

@media only screen and (max-width: 1100px) {
    .masonry-container{
        -webkit-column-count: 2;
    -moz-column-count: 2;
    column-count: 2;
    }
}
@media only screen and (max-width: 670px) {
    .masonry-container{
        -webkit-column-count: 1;
    -moz-column-count: 1;
    column-count: 1;
    }
}