after

  .pay-type_select-after,
  .amount-item_select-after {
    padding: 0;
    border: @wx-width-one_unit solid @color-main_blue;
    @v: @wx-width-one_unit*24;
    &:after {
      display: block;
      float: right;
      content: "√";
      background-color: @color-main_blue;
      color: #fff;
      border-radius: 50%; 
      font-size: @v;
    }
  }