.back-to-top {
  position: fixed;
  bottom: -60px;
  right: 20px;
  background-color: #479c4f;
  color: #fff;
  padding: 15px 20px;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  transition: background-color 0.3s, bottom 0.3s;
}

.back-to-top:hover {
  background-color: #4daa57;
}