#myBtn {
  display: none;
  position: fixed;
  bottom: 80px;
  right: 30px;
  z-index: 99;
  font-size: 50px;
  border: none;
  outline: none;
  color: white;
  cursor: pointer;
  padding: 15px;
  border-radius: 4px;
}

#myBtn:hover {
  color: #555;
}