.video-wrapper {
    width: 640px;
    max-width: 100%;
    margin: 20px auto 20px auto;
}

.youtube-aspect {
  position: relative;
  width: 100%;
  height: 0;
  padding-bottom: 56%;
  overflow: hidden;
}

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