.row{
    display:flex;
}
.col-md-4{
    width:33.33% !important;
}
    .col-md-4 iframe {
        height: 210px;
        width: 100%!important;
    }

@media only screen and (max-width: 976px) {
    .col-md-4 {
        width: 50% !important;
    }
    .row {
        display: block;
    }
}

@media only screen and (max-width: 676px) {
    .col-md-4 {
        width: 85% !important;
        margin: auto;
        float: initial!important;
    }
        .col-md-4 iframe {
            height: 210px;
        }

}