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

canvas {
  display: block;
  width: 100vw;
  height: 100vh;
}

.hint {
  position: fixed;
  left: 12px;
  bottom: 10px;
  padding: 8px 10px;
  border-radius: 10px;
  color: rgba(255,255,255,.60);
  background: rgba(0,0,0,.25);
  backdrop-filter: blur(6px);
  font: 12px/1.25 system-ui, -apple-system, "Segoe UI", sans-serif;
  user-select: none;
  transition: opacity .6s ease;
  opacity: 1;
}

.hint.hide {
  opacity: 0;
}