@media only screen and (min-width : 769px) {
    .bco-two-column-checkout #bco-order-review {
        float: left;
        width: 40%;
        padding-right: 20px;
        font-size: 0.9em;
        box-sizing: border-box;
    }

    .bco-two-column-checkout #bco-iframe {
        float: right;
        width: 60%;
        padding-left: 20px;
        box-sizing: border-box;
    }
}