At the top of your app/assets/stylesheets/application.css file you should see something like this.
/*
This is a manifest file that’ll automatically include all the stylesheets available in this directory
and any sub-directories. You’re free to add application-wide styles to this file and they’ll appear at
the top of the compiled file, but it’s generally better to create a new file per style scope.
*= require_self
*= require_tree .
*/
The two comments at the bottom tell Sprockets to build a compiled asset file using first the contents of this file and then the contents of every other file in this directory. If the import order matters to you, you’ll need to replace the require_tree directive with individual requests to require each file in the order you need. Ex:
/*
This is a manifest file that’ll automatically include all the stylesheets available in this directory
and any sub-directories. You’re free to add application-wide styles to this file and they’ll appear at
the top of the compiled file, but it’s generally better to create a new file per style scope.