$i: 0;
    $width: 0;
    $left: 0;
    @while $i < 6 {
      $i: $i + 1;
      $left: $left + $width;
      @if ($i == 1) {

 $width: 160px;
      } @else if ($i == 2){
        $width: 230px;
      } @else if ($i == 3){
        $width: 130px;
      } @else if ($i == 4){
        $width: 140px;
      } @else if ($i == 5){
        $width: 200px;
      }
      .i-#{$i} a {
        width: $width;
        background-position: -$left 0;
        &:hover {
          background-position: -$left -100px;
        }
      }
    }
  }