Patrick Clancey's CSS Mod Queries and Range Selectors

mixin.scss

// http://alistapart.com/article/using-css-mod-queries-with-range-selectors

// range selector mixin
@mixin select-range($start, $end){
  &:nth-child(n+#{$start}):nth-child(-n+#{$end}){
   @content;
   }
}
// mod query mixin
@mixin mod-list($mod, $remainder){
  &:nth-last-child(#{$mod}n+#{$remainder}):first-child,
  &:nth-last-child(#{$mod}n+#{$remainder}):first-child ~ li {
    @content;
    }
}

li {
@include mod-list(3, 0){
  @include select-range(3, 5){
    // styles for items 3 to 5 in a list mod 3 remainder = 0
    }
  }
}