@mixin parent {
	@each $selector in & {
		@if length($selector) == 1 {
			$selector: nth($selector, 1);
		}
		$l: length($selector);

		@if ($l == 1) {
			@error 'Used parent mixin on a top-level selector';
		} @else {
			$parent: nth($selector, 1);
			@for $i from 2 to $l {
				$parent: append($parent, nth($selector, $i));
			}

			@at-root #{$parent} {
				@content;
			}
		}
	}
}