#myBtnTopScreen {
  display: none;
  position: fixed;
  bottom: 50px;
  right: 75px;
  z-index: 99;
  font-size: 25px;
  border: none;
  outline: none;
  color: white;
  background-color: #194a6b;
box-shadow: 0 5px 25px 0 rgba(0, 0, 0, 0.2), 0 10px 20px 0 rgba(0, 0, 0, 0.19);
  cursor: pointer;
  padding: 5px;
  border-radius: 45px;
}


#myBtnTopScreen:hover {
  background-color: #555;
}