html,
body {
  margin: 0;
  width: 100%;
  height: 100%;
  background: #000;
}

body {
  overflow: hidden;
}

* {
  box-sizing: border-box;
}

.viewer-shell {
  width: 100vw;
  height: 100vh;
}

iframe {
  width: 100%;
  height: 100%;
  border: 0;
  display: block;
  background: #000;
}