.#{$backtop} {
  position: fixed;
  background-color: #FFF;
  width: size(40px);
  height: size(40px);
  border-radius: 50%;
  color: var(--main-color);
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center;
  font-size: size(20px);
  box-shadow: var(--box-shadow-md);
  cursor: pointer;
  z-index: 5;

  &:hover {
    background-color: var(--bg-light);
  }
}