title: Joosy tutorial ActionView::Template::Error
body: <p>I was going through the <a href="http://guides.joosy.ws/guides/blog/rails-preparations.html" rel="nofollow">Joosy Guide</a> but at the end of "Rails Preparation" section instead of the landing page, I get the following error:</p>
  
  <pre><code>ActionView::Template::Error (Mixin grid-core-span is missing argument $gridColumnWidth.
    (in /Users/scribe/Code/joosy-blog/app/assets/stylesheets/application.css.scss)):
      10:       };
      11:     &lt;/script&gt;
      12: 
      13:     &lt;%= stylesheet_link_tag 'application' %&gt;
      14:     &lt;%= csrf_meta_tags %&gt;
      15:   &lt;/head&gt;
      16: 
    app/assets/stylesheets/application.css.scss:1
    app/views/layouts/blog.html.erb:13:in `_app_views_layouts_blog_html_erb___1369399347943123030_70192156915780'
    app/controllers/blog_controller.rb:5:in `index'
  </code></pre>
  
  <p>As far as I can tell I my project matches the instructions, any ideas as to what I messed up?</p>