Page
When you mention a "static" page -- all the pages are static in Rails
Rails just renders HTML, using the data from your database. Much like PHP (which many developers can appreciate), Rails is a processor which allows you to populate your view with the data you need.
This means that if you want to make a "static" page, you just need to not pull any data from the db:
#config/routes.eb
root: "application#home"
#app/controllers/application_controller.rb
class ApplicationController < ActionController::Base
def home
end
end
This will give you the ability to load the following view:
#app/views/application/home.html.erb
Put stuff here
Assets
Now, the slightly trickier part is to include the right assets for this view.
You mention you have your own directory structure. Let me tell you now that you'll be MUCH better served by creating & serving assets from your assets pipeline.
Here's how:
#app/views/layouts/application.html.erb
<head>
...
<% if controller_name == "application" && action_name == "home" %>
<%= stylesheet_link_tag "welcome" %>
<%= javascript_include_tag "welcome" %>
<% end %>
</head>
This will give you the ability to call the following:
#app/assets/stylesheets/welcome.css
...
#app/assets/javascripts/welcome.js
...
Finally, if you then add the "welcome" files to your asset precompilation list, it should work for you:
#config/application.rb
Rails.application.config.assets.precompile += ['welcome.js', 'welcome.css']