.embed-responsive-video {
  position: relative;
  width: 100%;
  max-width: 1200px; /* scale-up control */
  margin: 0 auto;
  aspect-ratio: 16 / 9;
}

.embed-responsive-video iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}