app/views/user_sessions/new.html.erb
<div class="vertical-center">
<div class="container">
<div class="page-header">
<div class="row">
<div class="user-page col-xs-12">
<h1>Sign in</h1>
</div>
</div>
</div>
<div class="row">
<div class="col-md-6">
<%= form_for @user, url: user_session_path, method: :post, role: 'form' do |f| %>
<div class="form-group">
<%= f.label :email %>
<%= f.email_field :email, autofocus: true, class: 'form-control' %>
</div>
<div class="form-group">
<%= f.label :password %>
<%= f.password_field :password, autocomplete: 'off', class: 'form-control' %>
</div>
<div class="form-group">
<%= f.submit 'Login', class: 'btn btn-success btn-block btn-lg' %>
</div>
<% end %>
</div>
</div>
</div>