mixin view-heading 
    +view('heading', 'Heading')
        .c-box
            +div-heading('xxl')= 'XXL Heading'
            +div-heading('xl')= 'XL Heading'
            +div-heading('lg')= 'LG Heading'
            +div-heading('md')= 'MD Heading'
            +div-heading('sm')= 'SM Heading'
            +div-heading('xs')= 'XS Heading'