.cm-3col__item {
    width: calc(50% - 20px);
    margin-right: 40px;
}
.cm-3col__item:nth-of-type(2) {
    width: calc(50% - 20px);
    margin-right: 0;
}
@media only screen and (max-width: 767px) {
    .cm-3col__item,.cm-3col__item:nth-of-type(2) {
        width: 100%;
        margin: 0 0 30px;
    }
}