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

canvas {
  display: block;
}

.serve-btn {
  position: fixed;
  top: 20px;
  left: 20px;
  transform: none;
  padding: 10px 20px;
  background-color: #ffffff;
  color: #000000;
  border: 2px solid #000000;
  border-radius: 5px;
  cursor: pointer;
  font-size: 16px;
  transition: all 0.3s ease;
  z-index: 1000;
}

.serve-btn:hover {
  background-color: #f0f0f0;
}

.serve-btn:active {
  background-color: #e0e0e0;
}

.marble-btn {
  position: fixed;
  top: 20px;
  left: 160px;
  padding: 10px 20px;
  font-size: 16px;
  background-color: #ffffff;
  color: #000000;
  border: 2px solid #000000;
  border-radius: 5px;
  cursor: pointer;
  z-index: 1000;
  transition: all 0.3s ease;
}

.marble-btn:hover {
  background-color: #f0f0f0;
}

.marble-btn:active {
  background-color: #e0e0e0;
}