.content {
    width: 50%;
    margin: 0px auto;
}

.embed-container {
    height: 0;
    width: 100%;
    padding-bottom: 56.25%;
    overflow: hidden;
    position: relative;
}

    .embed-container iframe {
        width: 100%;
        height: 100%;
        position: absolute;
        top: 0;
        left: 0;
    }