@mixin isMedia($values: null) {
    @each $mediaClass, $mediaSize, $mediaBase in $mediaQs {
        $mb: $mediaBase;
        @if $mediaClass == $mediaQ-base {
            $mc: #{$mediaClass};
            @if $values {
                @each $size, $val in $values {
                    @if $size == $mediaClass {
                        @content($val, $mb);
                    }
                }
            } @else {
                @content($mc, $mb);
            }
        } @else {
            @media ($mediaSize) {
                $mc: \@#{$mediaClass};
                @if $values {
                    @each $size, $val in $values {
                        @if $size == $mediaClass {
                            @content($val, $mb);
                        }
                    }
                } @else {
                    @content($mc, $mb);
                }
            }
        }
    }
}