*
{
    margin: 0;
    padding: 0;
}

html,
body
{
    overflow: hidden;
}

.webgl
{
    position: fixed;
    top: 0;
    left: 0;
    outline: none;
}

button.serve-btn {
  position: absolute;
  top: 20px;
  left: 20px;
  z-index: 20;
  padding: 10px 20px;
  background-color: #4CAF50;
  color: white;
  border: none;
  font-size: 16px;
  cursor: pointer;
}