.container {
  position: relative;
  overflow: hidden;
  width: 100%;
  height: 0;
  padding-top: 25px; /* 16:9 Aspect Ratio (divide 9 by 16 = 0.5625) */
  padding-bottom: 56.25%; /* 16:9 */
}


/* Then style the iframe to fit in the container div with full height and width */
.responsive-iframe {
  position: absolute;
  top: 0;
  left: 0;  
  width: 100%;
  height: 100%;
}