.scroll-to-top {
  position: fixed;
  right: 10px;
  bottom: 10px;
  z-index: 2;
  opacity: 0;
  transform: translateY(100px);
}

.scroll-to-top a {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 60px;
  height: 60px;
  background: var(--orange);
  color: #fff;
  border-radius: 50%;
  font-size: 1.6rem;
  text-decoration: none;
  text-transform: uppercase;
  backdrop-filter: blur(5px);
  transition: 0.3s;
}

.scroll-to-top a:hover {
  background: var(--pink);
  transform: scale(1.1);
}

.scroll-to-top.UpMove {
  animation: fadeUp 0.5s forwards;
}

.scroll-to-top.DownMove {
  animation: fadeDown 0.5s forwards;
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(100px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeDown {
  from { transform: translateY(0); }
  to   { transform: translateY(100px); }
}