#btnScrollTop {
  display: none;
  position: fixed;
  bottom: 25px;
  right: 25px;
  z-index: 9999;
  background-color: #4a6ca1;
  color: white;
  border: none;
  outline: none;
  padding: 12px 16px;
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 2px 6px rgba(0,0,0,0.3);
  transition: opacity 0.3s ease;
}
#btnScrollTop:hover {
  background-color: #4a6ca1;
}