@mixin variant($variant-name, $type: 'default') {
    @if $type == 'form' {
        .form.-#{$variant-name} &,
        .form-group.-#{$variant-name} &,
        &.-#{$variant-name} {
            @content;
        }
    } @else {
        &.-#{$variant-name} {
            @content;
        }
    }
}