.to-top-btn {
  position: fixed;
  bottom: 24px;
  right: 32px;
  width: 50px;
  height: 50px;
  border: none;
  background-color: #adccf9;
  box-shadow: 0 0 5px rgba(0, 0, 0, 0.17);
  font-size: 20px;
  font-weight: 700;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.5s ease, visibility 0.5s ease, box-shadow 0.5s ease,
    background 0.5s ease;
  z-index: 999;
}

.to-top-btn:hover {
  box-shadow: 0 0 25px rgba(0, 0, 0, 0.17);
}

.to-top-btn.active {
  opacity: 1;
  visibility: visible;
}