Create nested ordered lists with LESS, automatically prefixing sub-list items

nested-ordered-lists.less

/**
 * Creates nested ordered lists, for example:
 *
 * <h1>First Section</h1>
 * <ol>
 *     <li></li>
 *     <li></li>
 *     <li></li>
 * </ol>
 * <h1>Second Section</h1>
 * <ol>
 * 1. First Section
 *     1.1 first sub item
 *     1.2 second sub item
 *     1.3 second sub item
 * 2. Second Section
 */

#ilist (@i) when (@i > 9) {
	& ol:nth-of-type(@{i}) > li:before {
        content:'@{i}.';
        margin: 0 20px 0 -42px;
    }
    & ol:nth-of-type(@{i}) > li:nth-of-type(n+10):before {
        content:'@{i}.';
        margin: 0 28px 0 -40px;
    }
    #ilist (@i - 1);
}

#ilist (@i) when (@i < 10) and (@i > 0) {
    & ol:nth-of-type(@{i}) > li:before {
        content:'@{i}.';
        margin: 0 21px 0 -34px;
    }
    & ol:nth-of-type(@{i}) > li:nth-of-type(n+10):before {
        content:'@{i}.';
        margin: 0 28px 0 -40px;
    }
    #ilist (@i - 1);
}

#ilist (0) {}

#nested-ordered-lists {
    &-wrapper {
        overflow: hidden;
    }
    #ilist (20);
    #ilist (9);
}