.videoWrapper {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 */
    padding-top: 25px;
    height: 0;
}

    .videoWrapper iframe {
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
    }
@media screen and (max-width: 767px) {
    .videoWrapper {
        padding-bottom: 154.25%;
    }
}