=modifier($name)
    @at-root
        $selector: nth(&, 1)
        $direct-parent: nth($selector, length($selector))
        #{$direct-parent}--#{$name}
            @extend #{$direct-parent} !optional
        #{&}--#{$name}
            @content

=element($name)
    @at-root
        #{&}__#{$name}
            @content