.pagetop {
  height: 50px;
  width: 50px;
  position: fixed;
  right: 30px;
  bottom: 30px;
  background: #fff;
  border: solid 2px #000;
  border-radius: 50%;
  display: none;
  justify-content: center;
  align-items: center;
  z-index: 10;
  cursor: pointer;
}
.pagetop__arrow {
  display: block;
  height: 10px;
  width: 10px;
  border-top: 3px solid #000;
  border-right: 3px solid #000;
  transform: translateY(20%) rotate(-45deg);
}