anchor.diff:  <div class="card">
     <div class="card-header text-center">
  -    <ul class="nav nav-pills" role="tablist">
  +    <ul class="nav nav-tabs" role="tablist">
         <div class="row">
           <% @root_topics.each do |rt| %>
             <li class="nav-item">
  -            <a class="nav-link" data-animation="false" data-toggle="pill" href="#<%= rt.name.parameterize.underscore %>" role="tab">
  +            <a class="nav-link" data-toggle="tab" href="#<%= rt.name.parameterize.underscore %>" role="tab">
                 <%= rt.name.titleize %>
               </a>
             </li>
  
positive.code:     </div>
    </div>
  </div>
  
negative.code:   </div>
    <div class="card-block">
      <div class="tab-content">
        <% @root_topics.each_with_index do |rt, i| %>
  
          <div class="tab-pane fade <%= "show in" if i == 0 %>" role="tabpanel" id="<%= rt.name.parameterize.underscore %>">
            <% @discussion_topic = Topic.roots.where(name: "#{rt.name}")[0].self_and_descendants %>
            <% case rt.name %>
            <% when 'family history' %>
              <%= render 'family_members/family_tree', f: f %>
  