module Sprockets::Server

def css_exception_response(exception)
  message   = "\n#{exception.class.name}: #{exception.message}"
  backtrace = "\n  #{exception.backtrace.first}"
  body = <<-CSS
    html {
      padding: 18px 36px;
    }
    head {
      display: block;
    }
    body {
      margin: 0;
      padding: 0;
    }
    body > * {
      display: none !important;
    }
    head:after, body:before, body:after {
      display: block !important;
    }
    head:after {
      font-family: sans-serif;
      font-size: large;
      font-weight: bold;
      content: "Error compiling CSS asset";
    }
    body:before, body:after {
      font-family: monospace;
      white-space: pre-wrap;
    }
    body:before {
      font-weight: bold;
      content: "#{escape_css_content(message)}";
    }
    body:after {
      content: "#{escape_css_content(backtrace)}";
    }
  CSS
  [ 200, { "Content-Type" => "text/css;charset=utf-8", "Content-Length" => Rack::Utils.bytesize(body).to_s }, [ body ] ]
end