.column {
    float: left;
}
.size-1of4 {
    width: 25%;
}
.size-1of3 {
    width: 33.333%;
}
.size-1of2 {
    width: 50%;
}
#timeline img {
    display: block;
    width: 100%;
    max-width: 100%;
}
#timeline {
    overflow: hidden;
}
@media screen and (max-width: 450px) {
    #timeline[data-columns]::before {
        content: '1 .column';
    }
}

@media screen and (min-width: 451px) and (max-width: 700px) {
    #timeline[data-columns]::before {
        content: '2 .column.size-1of2';
    }
}

@media screen and (min-width: 701px) and (max-width: 991px) {
    #timeline[data-columns]::before {
        content: '3 .column.size-1of3';
    }
}

@media screen and (min-width: 992px) {
    #timeline[data-columns]::before {
        content: '4 .column.size-1of4';
    }
}