app/views/devise/registrations/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">
Sign up
</h2>
<%= form_for(resource, as: resource_name,
url: registration_path(resource_name), validate: true) do |f| %>
<%= devise_error_messages! %>
<div class="form-group mt-4">
<%= f.label :name, "What's your name?" %>
<%= f.text_field :name, autofocus: true,
placeholder: "Doris", class: "form-control" %>
</div>
<div class="form-group mb-2rem">
<%= f.label :email, "What's your email?" %>
<%= f.email_field :email, autocomplete: "email",
placeholder: "doris@email.com", class: "form-control" %>
</div>
<div class="form-group mb-4">
<%= f.button "Sign up",
class: "btn btn-primary btn-block btn-lg btn-3d",
data: { disable_with: "Signing you up... #{render 'spinner'}" } %>
</div>
<% end %>
</div>
</div>
</div>