.bb_scroll_top>i {
  font-size: 36px;
  font-weight: 300;
}
.bb_scroll_top {
  width: 45px;
  height: 45px;
  border-radius: 45px;
  padding: 2px;
  text-align: center;
  position: fixed;
  bottom: 28px;
  right: 50px;
  z-index: 999;
  cursor: pointer;
  box-shadow: 0 2px 2px 0 rgba(0,0,0,0.16), 0 0 0 1px rgba(0,0,0,0.08);
  display: none;
}