CSS post-processor which generates pixel fallbacks for rem units in your Rails (Sinatra) application.

Add rails-pixrem to your Gemfile:

gem 'rails-pixrem', github: 'vast/rails-pixrem'

Write your CSS (SASS, Stylus, LESS) using rems:

#header {
  font-size: 2rem;
}

Rails-pixrem will automatically add fallback rules with pixel values:

#header {
  font-size: 32px; // IE8, Opera Mini
  font-size: 2rem; // modern browsers
}

If you use a non-Rails framework with Sprockets, connect Sprockets environment with RailsPixrem:

assets = Sprockets::Environment.new do |env|
  # ...
end

require 'rails-pixrem'
RailsPixrem.install(assets)

You can specify root element font size (default: '16px') in px, em or percents:

# config/pixrem.yml
root_value: 24px

RailsPixrem.install(assets, root_value: '85%')