Wrap devise views in a well

Wrap devise views in a well

So I am using devise. its all fun, but I need to wrap all the views in a
nice span3.well and center them. I figure the code is quite simple. So
here's what I want to do:
<div class="row-fluid">
<div class="span4 offset4 well">
<h2>Sign up</h2>
<%= form_for(resource, :as => resource_name, :url =>
registration_path(resource_name), :class=>"form-horizontal") do |f| %>
<%= devise_error_messages! %>
<div><%= f.label :name %><br />
<%= f.text_field :name, :autofocus => true %></div>
<div><%= f.label :email %><br />
<%= f.email_field :email, :autofocus => true %></div>
<div><%= f.label :password %><br />
<%= f.password_field :password %></div>
<div><%= f.label :password_confirmation %><br />
<%= f.password_field :password_confirmation %></div>
<div><%= f.submit "Sign up" %></div>
<% end %>
<%= render "devise/shared/links" %>
</div>
</div>
I want to wrap this on all devise views so I want to create a structure like:
So I'd save this as a erb file and figure out some way of doing this
wrapping without modifying each of devise views