// scss
$swiper-wrappers: ('swiper-wrapper', 'gallery-item-list', 'gallery-thumb-list');

$swiper-wrapper-classes: ();

@each $swiper-wrapper in $swiper-wrappers {
  $swiper-wrapper-classes: append($swiper-wrapper-classes, unquote('.#{$swiper-wrapper}'), comma);
}

#{$swiper-wrapper-classes} {
  background: #000;
}