html, body {
  height: 100%;
  background: #fff;
}

body {
  margin: 0;
  background: #fff;
  overflow: hidden;
  display: grid;
  place-items: center;
}

#viewer {
  width: 100vw;
  height: 100vh;
  border: none;
  opacity: 0;
  transition: opacity 1.5s ease-in-out;
  place-self: stretch;
  background: #fff;
}

/* Logo overlay */
#logo-overlay {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
  background: #fff;
  opacity: 0;
  pointer-events: none;
  transition: opacity 1.5s ease-in-out;
}

#logo-overlay.show {
  opacity: 1;
}

#logo-overlay .logo {
	width: 40%;
	height: auto;
	margin: 0 auto;
	display: block;
}