app/views/devise/sessions/new.html.erb
<%= content_for :title do %>ログイン<% end %>
<div class="page-header">
<h1>ログイン</h1>
</div>
<%= form_for(resource,
as: resource_name,
url: session_path(resource_name),
html: { class: 'form-horizontal' }
) do |f| %>
<%= render partial: 'shared/form_error', locals: { object: resource } %>
<div class="form-group">
<%= f.label :email, class: 'control-label col-sm-2' %>
<div class="col-sm-4">
<%= f.email_field :email,
autofocus: true,
class: 'form-control' %>
</div>
</div>
<div class="form-group">
<%= f.label :password,
class: 'control-label col-sm-2' %>
<div class="col-sm-4">
<%= f.password_field :password,
autocomplete: "off",
class: 'form-control' %>
</div>
</div>
<% if devise_mapping.rememberable? -%>
<div class="form-group">
<div class="col-sm-offset-2 col-sm-4">
<%= f.check_box :remember_me %> <%= f.label :remember_me %>
</div>
</div>
<% end -%>
<div class="form-group">
<div class="col-sm-offset-2 col-sm-10">
<%= f.submit 'ログイン', class: 'btn btn-primary btn-sm' %>
</div>
</div>
<% end %>
<br>
<%= render "devise/shared/links" %>