/* Scroll to top button */
#myBtn {
  display: none; 
  position: fixed;
  bottom: 20px; 
  left: 50%; 
  transform: translateX(-50%); 
  z-index: 99; 
  border: 1px solid lightskyblue; 
  outline: none; 
  background-color: blue; 
  color: whitesmoke;
  cursor: pointer; 
  padding: 10px; 
  border-radius: 16px; 
  font-size: 18px; 
  opacity: 0.5;
}

#myBtn:hover {
  background-color: #003;
}