class Sprockets::CharsetNormalizer

environment.unregister_bundle_processor ‘text/css’, Sprockets::CharsetNormalizer
This behavior can be disabled with:
approach would be to re-encode stylesheets with mixed encodings.
the other definitions are usually ‘UTF-8`. A more sophisticated
it sees and strips the others. This works for most people because
The current implementation is naive. It picks the first `@charset`
definitions.
The `CharsetNormalizer` processor strips out multiple `@charset`
concatenates them together.
it inserts a `@charset` at the top of each file. Then Sprockets
`@charset` definitions. The issue surfaces while using Sass since
Some browsers have issues with stylesheets that contain multiple

def evaluate(context, locals, &block)

def evaluate(context, locals, &block)
  charset = nil
  # Find and strip out any `@charset` definitions
  filtered_data = data.gsub(/^@charset "([^"]+)";$/) {
    charset ||= $1; ""
  }
  if charset
    # If there was a charset, move it to the top
    "@charset \"#{charset}\";#{filtered_data}"
  else
    data
  end
end