position: fixed;
bottom: 0;

respond_to do |format|
  format.html {render :layout => nil}
  format.pdf do
    render :pdf => "file_name.pdf",

    :save_to_file => Rails.root.join('public/uploadedfiles', "filename")
  end
end

@page {
  @bottom-center {
    content: "foo";
  }
}