html, body {
  height: 100%;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background: #000;
}

canvas {
  display: block;
  width: 100vw !important;
  height: 100vh !important;
  position: fixed;
  top: 0;
  left: 0;
}

#hint {
  position: fixed;
  left: 50%;
  top: 50%;
  transform: translate(-50%,-50%);
  color: #fff;
  background: rgba(0,0,0,0.7);
  padding: 18px 30px;
  border-radius: 18px;
  font-size: 1.3em;
  z-index: 10;
  pointer-events: none;
  transition: opacity 1s;
}