anchor.diff:              </div>
             </li>
           <% else %>
  -          <li class="nav-item mr-2">
  +          <li class="nav-item ml-md-auto">
               <%= link_to 'Sign in', new_user_session_path, class: 'nav-link' %>
             </li>
  -          <li class="nav-item">
  -            <%= link_to 'Sign up', new_user_registration_path, class: 'btn btn-outline-primary', role: 'button' %>
  -          </li>
  +          <% unless content_for(:page) == 'home' %>
  +            <li class="nav-item ml-md-2">
  +              <%= link_to 'Sign up', new_user_registration_path, class: 'btn btn-outline-primary', role: 'button' %>
  +            </li>
  +          <% end %>
           <% end %>
         </ul>
       </div>
  
positive.code: <nav class="navbar navbar-expand-md mb-3 <%= content_for(:page) == 'home' ? 'navbar-dark' : 'navbar-light bg-light' %>">
    <div class="container">
      <a class="navbar-brand" href="/"><%= fa_icon("camera") %> Picture</a>
  
      <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
      </button>
  
      <div class="collapse navbar-collapse" id="navbarNav">
        <ul class="navbar-nav">
          <li class="nav-item<%= ' active' if content_for(:page) == 'explore' %>">
            <%= link_to 'Explore', explore_path, class: 'nav-link' %>
          </li>
  
negative.code:           <%= link_to 'Upload', new_picture_path, class: 'nav-link' %>
          </li>
          <% unless %w(home search).include? content_for(:page) %>
            <li class="nav-item ml-md-2 my-md-0 my-2">
              <%= render 'layouts/search' %>
            </li>
          <% end %>
  
          <% if user_signed_in? %>
            <li class="nav-item ml-md-auto dropdown">
              <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false" style="line-height:30px;padding:5px 0">
                <% if current_user.avatar? %>
                  <%= image_tag(current_user.avatar.thumb_url('60x60'), alt: 'avatar', class: 'rounded-circle', width: 30, height: 30) %>
  