body {
  background-color: lightblue;
  /* leave it to hide the scrollbars */
  overflow: hidden;
}

#app {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  background-color: gray;
  display: flex;
  justify-content: center;
  align-items: center;
}

#app canvas {
  object-fit: contain;
  max-height: 100%;
  max-width: 100%;
  box-shadow: 0px 0px 14px rgb(0 0 0 / 30%);
}