devdocs/assets/stylesheets/pages/_yii.scss

._yii {
  h2 { @extend %block-heading; }
  h3 { @extend %block-label, %label-blue; }
  h4 { font-size: 1em; }

  blockquote { @extend %note; }

  .detail-header-tag, .detailHeaderTag {
    float: right;
    color: $textColorLight;
  }
}