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;
}

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

.marbles-btn {
  position: absolute;
  top: 70px;
  left: 20px; /* Positioned to the right of the serve button */
  padding: 10px 20px;
  font-size: 16px;
  z-index: 1;
  cursor: pointer;
}
.particle-controls {
  position: fixed;
  top: 180px;
  left: 20px;
  z-index: 100;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.particle-controls button {
  padding: 8px 16px;
  background: rgba(0, 0, 0, 0.7);
  color: white;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  font-family: inherit;
  font-size: 14px;
}
.particle-controls button:hover {
  background: rgba(100, 100, 100, 0.7);
}