.media {
}

.media-iframe-parent {
  margin: 0;
  width: 100%;
  position: relative;
  padding-bottom: 56.25%; /* 16:9 */
  box-sizing: content-box;
}

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