Scss works in rails Heroku production but not in staging version

Scss works in rails Heroku production but not in staging version

I have a rails application on Heroku that works fine [including scss].
However when i try to set up a Heroku staging version by setting up a copy
of the environment/production.rb as environment/staging.rb and using the
following commands:
$ heroku create --remote staging
$ heroku config:add RACK_ENV=staging RAILS_ENV=staging --remote staging
$ git push staging master
$ heroku run rake db:migrate --remote staging
$ heroku open --remote staging
the staging application on heroku runs but without all the scss/css.
Why does scss work in production but not staging?? I thought i understood
what the problem was but i now realize I don't. What do i need to fix?