#btnScrollToTop {
  display: none;
  position: fixed;
  bottom: 20px;
  right: 20px;
  z-index: 99;
  border: none;
  outline: none;
  background-color: var(--border-cabecera-mobile);
  color: white;
  cursor: pointer;
  padding: 10px;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  font-size: 25px;
}

#btnScrollToTop:hover {
  background-color: #333;
}