.#{$backtop-prefix-cls} {
  z-index: $zindex-fixed;
  position: fixed;
  cursor: pointer;
  display: none;
  .aid-arrow-up-bold-circle {
    font-size: 48px;
    color:  rgba(0,0,0,0.45);
    &:hover {
      color: rgba(0,0,0,0.65);
    }
  }
  &--show {
    display: block;
  }
}