body, html {
  margin: 0; padding: 0; overflow: hidden;
  background: #111;
  font-family: Arial, sans-serif;
  color: #eee;
  height: 100%;
  user-select: none;
}

#instructions {
  position: fixed;
  top: 10px; left: 50%;
  transform: translateX(-50%);
  background: rgba(0,0,0,0.7);
  padding: 10px 15px;
  border-radius: 6px;
  font-size: 14px;
  z-index: 10;
}

#hud {
  position: fixed;
  top: 10px; left: 10px;
  background: rgba(0,0,0,0.6);
  padding: 10px 15px;
  border-radius: 8px;
  font-size: 14px;
  z-index: 10;
}

#settingsMenu {
  position: fixed;
  top: 10px; right: 10px;
  background: #222;
  color: #eee;
  padding: 15px 20px;
  border-radius: 8px;
  width: 250px;
  font-size: 14px;
  z-index: 10;
}

#settingsMenu button {
  margin-top: 5px;
  width: 100%;
  padding: 8px;
  background: #444;
  border: none;
  color: #eee;
  font-size: 14px;
  cursor: pointer;
  border-radius: 4px;
}

#settingsMenu button:hover {
  background: #666;
}

canvas {
  display: block;
}