title: How to require a specific file in application.css
body: <p>I am trying to require "font-awesome.scss" in the application.css of my Rails 4 app like this:</p>
  
  <pre><code>/*
   * This is a manifest file that'll be compiled into application.css, which will include all the files
   * listed below.
   *
   * Any CSS and SCSS file within this directory, lib/assets/stylesheets,    vendor/assets/stylesheets,
   * or any plugin's vendor/assets/stylesheets directory can be referenced here using a relative path.
   *
   * You're free to add application-wide styles to this file and they'll appear at the bottom of the
   * compiled file so the styles you add here take precedence over styles defined in any styles
   * defined in the other CSS/SCSS files in this directory. It is generally better to create a new
   * file per style scope.
   *
   *= require 'font-awesome.scss'
   *= require_tree .
   *= require_self
   */
  </code></pre>
  
  <p>'font-awesome.scss' imports a bunch of files that look like partials, with a preceding underscore. One of these partials (_variables.scss) defines a variable that I need to define as of the moment I get the following error message: </p>
  
  <pre><code>Sass::SyntaxError (Undefined variable: "$fa-css-prefix".
  (in /Users/bla/rails_projects/Homepage/app/assets/stylesheets/_bordered-pulled.scss:4)):
  app/assets/stylesheets/_bordered-pulled.scss:4
  app/views/layouts/application.html.erb:35:in `_app_views_layouts_application_html_erb__3531690645719711557_70221015865520'
  </code></pre>
  
  <p>What am I doing wrong? </p>