app/views/devise/shared/_registration.html.erb
<div class="container">
<div class="row">
<div class="col-md-6 col-md-offset-3">
<div class="panel panel-login">
<div class="panel-heading">
<div class="row">
<div class="col-xs-6">
<a href="#" class="<%= 'active' if current_page?(new_user_session_path) %>", id="login-form-link">Entrar</a>
</div>
<div class="col-xs-6">
<a href="#" class="<%= 'active' if current_page?(new_user_registration_path) %>", id="register-form-link">Criar conta</a>
</div>
</div>
<hr>
</div>
<div class="panel-body">
<div class="row">
<div class="col-lg-12">
<div id='login-form', style="<%= 'display: none' unless current_page?(new_user_session_path) %>">
<%= form_for(resource, as: resource_name, url: session_path(resource_name)) do |f| %>
<div class="form-group">
<%= f.email_field :email, autofocus: true, class: 'form-control', placeholder: 'e-mail' %>
</div>
<div class="form-group">
<%= f.password_field :password, autocomplete: "off", class: 'form-control', placeholder: 'senha' %>
</div>
<div class="help-block text-right">
<%= link_to 'Esqueceu a senha?', new_user_password_path %>
</div>
<div class="actions">
<%= f.submit "Entrar", class: 'btn btn-primary btn-block' %>
</div>
<div class="checkbox text-center">
<label><%= f.check_box :remember_me %> Lembrar-me</label>
</div>
<% end %>
</div>
<div id='register-form', style="<%= 'display: none' unless current_page?(new_user_registration_path) %>">
<%= form_for :user, url: :user_registration do |f| %>
<%= devise_error_messages! %>
<div class="form-group">
<%= f.text_field :name, autofocus: true, placeholder: 'nome', class: 'form-control' %>
</div>
<div class="form-group">
<%= f.text_field :cpf, autofocus: true, placeholder: 'cpf', class: 'form-control' %>
</div>
<div class="form-group">
<%= f.text_field :rg, autofocus: true, placeholder: 'rg', class: 'form-control' %>
</div>
<div class="form-group">
<%= f.email_field :email, autofocus: true, placeholder: 'e-mail', class: 'form-control' %>
</div>
<div class="form-group">
<%= f.password_field :password, autocomplete: "off", placeholder: 'senha (minimo: 8 caracteres)', class: 'form-control' %>
</div>
<div class="form-group">
<%= f.password_field :password_confirmation, autocomplete: "off", placeholder: 'confirme sua senha', class: 'form-control' %>
</div>
<div class="actions">
<%= f.submit "Criar conta", class: 'btn btn-primary btn-block' %>
</div>
<% end %>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>