anchor.diff:  
     <br>
   
  -  <%= link_to 'New Cost', new_cost_path %>
  +  <%= link_to 'New Cost',class: 'new-cost', new_cost_path %>
   
   </section><!--.costs-container-->
  
positive.code:     <tbody>
        <% @costs.each do |cost| %>
          <tr>
            <td><%= cost.title %></td>
            <td><%= cost.due %></td>
            <td><%= cost.amount %></td>
            <td><%= cost.parent_id %></td>
            <td><%= link_to 'Show', cost %></td>
            <td><%= link_to 'Edit', edit_cost_path(cost) %></td>
            <td><%= link_to 'Destroy', cost, method: :delete, data: { confirm: 'Are you sure?' } %></td>
          </tr>
        <% end %>
      </tbody>
  
negative.code:   <table class="costs-table">
      <thead>
        <tr>
          <th class="costs-col">Title</th>
          <th class="costs-col">Due</th>
          <th class="costs-col">Amount</th>
          <th class="costs-col">Parent</th>
          <th colspan="3"></th>
        </tr>
      </thead>
  