.ratiobox {
    display: block;
    position: relative;
    margin: 0;
    overflow: hidden;
}
.ratiobox_content {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
}
.ratiobox_content iframe {
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    width: 100%;
    height: 100%;
}
.ratiobox.ratio_16_9:after {
    padding-top: 56.25%;
}
.ratiobox:after {
    content: "";
    display: block;
    padding-top: 100%;
    overflow: hidden;
}