.wall {
    width: 100%;
    padding: 0 20px;
    -moz-column-gap: 20px;
    -webkit-column-gap: 20px;
    column-gap: 20px;
    -moz-column-count: 1;
    -webkit-column-count: 1;
    column-count: 1;
}
.wall > .brick {
    display: inline-block;
    width: 100%;
}

@media screen and (min-width:860px) {
    .wall {-moz-column-count: 2; -webkit-column-count: 2; column-count: 2;}
}

@media screen and (min-width:1280px) {
    .wall {-moz-column-count: 3; -webkit-column-count: 3; column-count: 3;}
}

@media screen and (min-width:1700px) {
    .wall {-moz-column-count: 4; -webkit-column-count: 4; column-count: 4;}
}