.rwd-video {
    height: 0;
    overflow: hidden;
    padding-bottom: 56.25%;
    padding-top: 30px;
    position: relative;
}
.rwd-video iframe,
.rwd-video object,
.rwd-video embed {
    height: 100%;
    left: 0;
    position: absolute;
    top: 0;
    width: 100%;
}