anchor.diff: -//- Обёртка карточки
  -    brand - primary, success, info, warning, danger
  -mixin card-wrap(brand)
  -    - var cardClass = ''
  -    - if (brand) cardClass += 'card-' + brand + ' card-inverse'
  -
  -    section.card(class=cardClass)&attributes(attributes)
  -        block
  -
   //- Заголовак карточки
   mixin card-title
       h4.card-title&attributes(attributes)
  +        block
  +
  +//- Дополнительный заголовак
  +mixin card-subtitle
  +    h6.card-subtitle.text-muted&attributes(attributes)
           block
   
   //- Изображенте карточки
  
positive.code:     p.card-text&attributes(attributes)
          block
  
  //- Подпись
  mixin card-caption
      +card-text: small.text-muted&attributes(attributes)
          block
  
  
negative.code: mixin card-img-bottom(src, alt)
      +img(src, alt).card-img&attributes(attributes)
  
  //- Обёртка изображения
  mixin card-img-overlay(src, alt)
      +card-img(src, alt)
      .card-img-overlay&attributes(attributes)
          block
  
  //- Цитата
  mixin card-blockquote
      blockquote.card-blockquote&attributes(attributes)
  