.columns_3070 {
    width: 100%;
}

    .columns_3070 > .leftColumn {
        width: 100%;
        margin-bottom: 20px;
    }

    .columns_3070 > .rightColumn {
        width: 100%;
    }


@media only screen and (min-width : 0px) {
}

@media only screen and (min-width : 768px) {
    .columns_3070 > .leftColumn {
        width: 30%;
        float: left;
    }

    .columns_3070 > .rightColumn {
        width: 70%;
        float: left;
    }
}