@media screen and (max-width: 560px) {
    .iframe-responsive {
      position: relative;
      width: 100%;
      padding: calc(315 / 560 * 100%) 0 0;
    }
    .iframe-responsive iframe {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
    }
}