#scroll-to-top {
  position: fixed;
  right: 25px;
  bottom: 25px;
  width: 4rem;
  height: 4rem;
  border-radius: 50px;
  background: var(--bs-secondary);
  text-align: center;
  box-shadow: 1px 2px 3px rgba(0,0,0,0.5);
  opacity: 0.80;
}