body {
  margin: 0;
  overflow: hidden;
}

canvas {
  display: block;
  background: black;
  width: 100%;
  height: 100%;
}

.controls {
  display: none;
  position: absolute;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  justify-content: space-between;
  width: 80%;
}

.control-btn {
  display: none;
  padding: 10px;
  font-size: 18px;
  background-color: rgba(0, 0, 0, 0.6);
  color: white;
  border: 1px solid #fff;
  border-radius: 5px;
  cursor: pointer;
  flex-grow: 1;
  margin: 0 5px;
}

@media (max-width: 600px) {
  .control-btn {
      display: block;
      font-size: 16px;
      padding: 12px;
  }
}