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

canvas {
  display: block;
}

.serve-btn {
  position: absolute;
  top: 20px;
  left: 20px;
  padding: 10px 20px;
  font-size: 16px;
  z-index: 1;
  cursor: pointer;
}

.marbles-btn {
  position: absolute;
  top: 20px;
  left: 120px; /* Positioned to the right of the serve button */
  padding: 10px 20px;
  font-size: 16px;
  z-index: 1;
  cursor: pointer;
}