app/views/devise/sessions/new.html.erb
<div class="container">
<div class="row justify-content-md-center">
<div class="col-md-6 mt-2rem mb-2rem">
<h2 class="text-center mt-2 mb-2rem">
Log in
</h2>
<%= form_for(resource, as: resource_name,
url: session_path(resource_name), validate: true) do |f| %>
<div class="form-group mt-4">
<%= f.label :email %>
<%= f.email_field :email, autofocus: true, autocomplete: "email",
placeholder: "doris@email.com", class: "form-control" %>
</div>
<div class="form-group">
<%= f.label :password %>
<%= f.password_field :password, autocomplete: "off",
placeholder: "password", class: "form-control" %>
</div>
<% if devise_mapping.rememberable? -%>
<div class="form-group">
<%= f.check_box :remember_me %>
<%= f.label :remember_me %>
</div>
<% end -%>
<div class="form-group mb-4">
<%= f.button "Log in",
class: "btn btn-primary btn-block btn-lg btn-3d",
data: { disable_with: "Logging you in..." } %>
</div>
<% end %>
<%= render "devise/shared/links" %>
</div>
</div>
</div>