Rails production: Google font imported is not loaded

Problem:

After seeing questions about this topic, I request your help.

/assets/stylesheets/styles.css: @import url("http://ift.tt/1cDTOkU");

When I run rails s on test or development, the font 'Merriweather' is loaded, but when I run server on production, the font is not loaded, but the styles.css is loaded.

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What I've tried:

• To put @import url(...) in application.css or welcome.scss or bootstrap.css.scss

• To change @import url('http://fonts.google...') by @import url('//fonts.google...')

Aditional info:

application.css

 *= require_tree .
 *= require_self
 *= require 'styles'

Github: http://ift.tt/1OYQTvs