#start-screen {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 10;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

#game-container:fullscreen {
  width: 100vw;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: black;
}

#game-container:fullscreen canvas {
  width: 100vw !important;
  height: 100vh !important;
  object-fit: fill;
}