school-platform/app/views/sessions/new.html.erb

<% provide(:title, "Log in") %>

<div class="row">
  <div class="col-md-4 col-md-offset-4">
    <div class="login-panel panel panel-default">
      <div class="panel-heading">
        <h3 class="panel-title">Please Sign In</h3>
      </div>
      <div class="panel-body">
        <%= form_for(:session, url: login_path) do |f| %>

          <div class="form-group">
            <%= f.label :username %>
            <%= f.text_field :login, class: 'form-control', autofocus: 'autofocus' %>
          </div>

          <div class="form-group">
            <%= f.label :password %>
            <%= f.password_field :password, class: 'form-control' %>
          </div>

          <%= f.label :remember_me, class: "checkbox inline" do %>
            <%= f.check_box :remember_me %>
            <span>Remember me on this computer</span>
          <% end %>

          <%= f.submit "Log in", class: "btn btn-lg btn-block btn-success" %>
        <% end %>
      </div>
    </div>
  </div>
</div>