.mainContent div.colLeft, .mainContenta div.colLeft {
    float: left;
    width: 48%;
}
.mainContent div.colRight, .mainContenta div.colRight {
    float: right;
    width: 48%;
}

.mainContenta{
    max-width: 800px !important;
}


@media screen and (max-width: 792px) {

    .mainContent div.colLeft, .mainContenta div.colLeft, .mainContent div.colRight, .mainContenta div.colRight {
        float:none;
        width:100%;
    }
}