.container {
  position: relative;
  overflow: hidden;
  width: 100%;
  /*padding-top: 56.25%; /* 16:9 Aspect Ratio (divide 9 by 16 = 0.5625) */
  padding-top: 100%; /* 1:1 Aspect Ratio */
  padding-left: 50%;

}

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