:not(:defined) > * {
  display: none;
}

body {
  background: transparent;
  margin: 0;
  padding: 0;
  width: 100vw;
  height: 100vh;
  background-color: transparent;
}

model-viewer {
  background: transparent;
  width: 100%;
  height: 90%;
  background-color: transparent;
}