Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.3.8)
// Compass (v1.0.0.alpha.19)
// ----

// Poor man's nth
// ---
// @param [number] $number: number of iterations
// @param [string] $selector: custom selector
// ---
@mixin nth($number, $selector: '*', $xtra:'') {
  @if type-of($number) != "number" {
    @warn "Invalid number for `nth`.";
  }
  
  @else {
    $generated-selector: '';
    
    @for $i from 1 to $number {
      $generated-selector: #{$generated-selector + '+' + $selector};
    }
    
    & #{$generated-selector} #{$xtra} {
      @content;
    }
  }
}


div {
  @include nth(3, li, ' > input[type="checkbox"]') {
    background-color: red;
  }
}

SassMeister-output.css

div + li + li > input[type="checkbox"] {
  background-color: red;
}