.btn-up {
  position: fixed;
  background-color: rgba(74, 106, 140, 0.2);
  right: 20px;
  bottom: 60px;
  border-radius: 25px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity 0.15s ease-in-out, transform 0.3s ease-in-out, background-color 0.5s ease-in-out;
  color: #fff;
  width: 50px;
  height: 50px;
  opacity: 1;
  transform: translateY(0);
  z-index:5;
}

.btn-up:hover {
  background-color: rgba(45, 93, 131, 1);
}

.btn-up_hide {
  display: none;
}

.btn-up_hiding {
  opacity: 0;
  transform: translateY(100px);
}

.btn-up-icon {
  width: 40px;
  height: 40px;
  fill: currentcolor;
}

@media (hover: hover) and (pointer: fine) {
  .btn-up:hover {
    background-color: rgba(37, 76, 106, 0.5);
  }
}