.yt-responsive {
  position: relative;
  width: 100%;
  padding-top: 56.25%; /* 16:9 */
  margin-bottom: 50px;
}
.yt-responsive iframe {
  border-radius; 3px;
  position: absolute;
  top: 0; left: 0;
  width: 100%;
  height: 100%;
  max-width:
}