.iframe {
  position: relative;
  display: block;
  width: 100%;
}

.iframe.is-aspect-16x9 {
  aspect-ratio: 16 / 9;
}

.iframe.is-aspect-4x3 {
  aspect-ratio: 4 / 3;
}

.iframe:is([class*="is-aspect-"], .is-cover)>iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}