<!DOCTYPE html>
<html>
<head>
  <title>actopus</title>
  <%= stylesheet_link_tag 'application', media: 'all' %>
  <%= javascript_include_tag 'application' %>
  <%= csrf_meta_tags %>
</head>
<body>
  <header>
    <div class="header-actopus">
      <h1>actopus</h1>
    </div>
  </header>
  <div class="container">
    <div class="row">
      <% if staff_signed_in? %>
        <div class="col-md-3">
          <div class="list-group">
            <%= staff_menu_item 'exchange', '時間割を変更する', '#' %>
            <%= staff_menu_item 'search', '時間割を見る', staffs_klasses_path %>
            <%= staff_menu_item 'th-list', '教員データを管理する', staffs_lecturers_path %>
            <%= staff_menu_item 'rotate-left', '時間割データを読み込む', new_staffs_timetable_path %>
          </div>
        </div>
        <div class="col-md-9">
          <%= render 'shared/messages' %>
          <%= yield %>
        </div>
      <% else %>
        <div class="col-md-offset-4 col-md-4">
          <%= render 'shared/messages' %>
          <%= yield %>
        </div>
      <% end %>
    </div>
  </div>
</body>
</html>

<!DOCTYPE html>
<html>
<head>
  <title>actopus</title>
  <%= stylesheet_link_tag 'application', media: 'all' %>
  <%= javascript_include_tag 'application' %>
  <%= csrf_meta_tags %>
</head>
<body>
  <header>
    <div class="header-actopus">
      <h1>actopus</h1>
    </div>
  </header>
  <div class="container">
    <div class="row">
      <% if staff_signed_in? %>
        <div class="col-md-3">
          <div class="list-group">
            <%= staff_menu_item 'exchange', '時間割を変更する', '#' %>
            <%= staff_menu_item 'search', '時間割を見る', staffs_klasses_path %>
            <%= staff_menu_item 'th-list', '教員データを管理する', staffs_lecturers_path %>
            <%= staff_menu_item 'rotate-left', '時間割データを読み込む', new_staffs_timetable_path %>
            <%= staff_menu_item 'users', 'スタッフを管理する', staffs_staffs_path %>
          </div>
        </div>
        <div class="col-md-9">
          <%= render 'shared/messages' %>
          <%= yield %>
        </div>
      <% else %>
        <div class="col-md-offset-4 col-md-4">
          <%= render 'shared/messages' %>
          <%= yield %>
        </div>
      <% end %>
    </div>
  </div>
</body>
</html>

Add a link to staffs managing page @sidebar
Add a link to staffs managing page @sidebar
