@sider-span: 20;
@prefixCls: 'idoll';


.make-sider-span() {
  .span(@index) {
    @item: ~".@{prefixCls}-layout-sider-@{index}";
    .span(@index, @item);
  }
  .span(@index, @list) when (@index <= @sider-span) {
    @{list} {
      width: @layout-sider-basic-width + 12 * @index;
    }
    .span((@index + 1));
  }
  .span(1);
}