.responsive-iframe-container {
  position: relative;
  padding-bottom: 56.25%; /* This is the aspect ratio for 16:9. Adjust as needed. */
  height: 0;
  overflow: hidden;
}

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