Semantic CSS with Twitter's Bootstrap

lace-usage

/* Next time you want to make a row or column, 
   use the .grid_row or .grid_col(n) mixin and be happy!
*/

.post {
  .grid_row;

  .post_date {
    .grid_cols(3);
  }

  .post_title {
    .grid_cols(13);
  }
}

lace.less

.grid_row {
    zoom: 1;
    margin-bottom: 18px;
    margin-left: -20px;

    :before, :after {
      display: table;
      content: "";
    }
    :after {
      clear: both;
    }
}

.grid_cols(@cols) {
    .columns(@cols);
    display: inline;
    float: left;
    margin-left: 20px;
}