ROR学习笔记（42）——assets pipeline分开打包

https://ruby-china.org/topics/25217
因为所有scss文件最后都会被application.scss打包成一个css文件

config.assets.precompile += ['nav.css', 'nav_m.css'] 
<%= stylesheet_link_tag "nav", media: "(min-width: 992px)" %>
<%= stylesheet_link_tag "nav_m", media: "(max-width: 992px)" %>

http://guides.ruby-china.org/asset_pipeline.html