.to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: #18bc9c !important;
  color: #fff !important;
  width: 60px;
  height: 60px;
  display: flex;
  justify-content: center;
  align-items: center;
  border-radius: 50%;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s, visibility 0.3s;
  z-index: 999;
}

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

.to-top:hover {
  background: #555;
}