* { box-sizing: border-box; }
.dudleystorey {
  background: #000;
  position: fixed;
  top: 0; right: 0; bottom: 0; left: 0;
}
.bananaphone,
.dudleystorey iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

@media (min-aspect-ratio: 16/9) {
  .bananaphone { height: 300%; top: -100%; }
}
@media (max-aspect-ratio: 16/9) {
  .bananaphone { width: 300%; left: -100%; }
}