html, body {
  margin: 0;
  height: 100%;
  background: #2b2926;
  overflow: hidden;
  overscroll-behavior: none;
}

#stage {
  display: block;
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
  -webkit-touch-callout: none;
  -webkit-tap-highlight-color: transparent;
}

.nojs {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
  margin: 0;
  color: #c9c3bb;
  font: 16px/1.4 system-ui, sans-serif;
}

/* Sound button: only shown on iPhone/iPad, where Safari will only start sound from a tap. */
#sound {
  position: fixed;
  top: calc(env(safe-area-inset-top, 0px) + 10px);
  right: calc(env(safe-area-inset-right, 0px) + 10px);
  width: 44px;
  height: 44px;
  padding: 9px;
  border: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.06);
  color: #c9ced4;
  opacity: 0.75;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
  cursor: pointer;
  transition: opacity 0.4s ease;
}
#sound[hidden] { display: none; }
#sound.on { opacity: 0.35; }
#sound svg { width: 100%; height: 100%; display: block; }
#sound .body { fill: currentColor; }
#sound .waves path, #sound .off path { fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; }
#sound .waves { display: none; }
#sound.on .waves { display: inline; }
#sound.on .off { display: none; }