* { margin: 0; padding: 0; box-sizing: border-box; }

html, body {
  width: 100%;
  height: 100%;
  background: #000;
  overflow: hidden;
  cursor: crosshair;
}

#stage {
  display: block;
  width: 100vw;
  height: 100vh;
  filter: drop-shadow(0 0 12px rgba(140, 255, 220, 0.6));
  mix-blend-mode: screen;
}