* { box-sizing: border-box; }

html, body {
  width: 100%;
  height: 100%;
  margin: 0;
  overflow: hidden;
  background: #000;
  cursor: crosshair;
  touch-action: none;
  user-select: none;
}

#canvas {
  position: fixed;
  inset: 0;
  display: block;
  width: 100%;
  height: 100%;
}

#video, #audio {
  position: fixed;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}