.youtube-content {
    width: 100%;
    padding-bottom: 20px;
}

.youtube-content iframe {
    padding-bottom: 20px;
}

@media (min-width:768px) {
    .youtube-content iframe {
        height: 400px;
    }
}

@media (min-width:992px) {
    .youtube-content iframe {
        height: 450px;
    }
}

@media (min-width:1200px) {
    .youtube-content iframe {
        height: 550px;
    }
}