body {
  margin: 0;
  overflow: hidden;
  background-color: #000;
}

canvas {
  display: block;
}

.control-btn {
  position: fixed;
  top: 20px;
  left: 20px;
  z-index: 100;
  padding: 10px 20px;
  background: rgba(255, 255, 255, 0.9);
  border: none;
  border-radius: 5px;
  cursor: pointer;
  font-family: Arial, sans-serif;
  transition: background 0.3s;
}

.control-btn:hover {
  background: rgba(255, 255, 255, 1);
}