case 'default_style':
            foreach (td_style_imported_settings::$td_array_import_settings_from_file as $import_setting_from_file) {
                td_global::$td_options[$import_setting_from_file] = '';
            }
            //typography settings
            td_global::$td_options['td_fonts'] = '';
            //css font files (google) buffer
            td_global::$td_options['td_fonts_css_files'] = '';
            //compile user css if any
            td_global::$td_options['tds_user_compile_css'] = td_css_generator();
            update_option(TD_THEME_OPTIONS_NAME, td_global::$td_options);
            $td_import_fonts_show_update_msg = true;
            break;
        default:
            if (array_key_exists($_REQUEST['td_option'], td_global::$stacks_list)) {
                $td_import_fonts_show_update_msg = td_import_demo_style_fonts($_REQUEST['td_option']);
            }
            break;
    }
}
//import demo style fonts only
function td_import_demo_style_fonts($file_style)
{
    $explode_nr_file = explode('_', $file_style);
    //read the settings file
    $file_settings = unserialize(base64_decode(file_get_contents(get_template_directory() . '/includes/stacks/' . $file_style . '.txt', true)));
    foreach (td_style_imported_settings::$td_array_import_settings_from_file as $import_setting_from_file) {
        /**
         *  we import a setting from the file only if it's not empty
         *  OR
         *  if the setting is td_body_classes we import it even as empty if needed
            $td_import_fonts_show_update_msg = true;
            break;
        case 'import_style_1':
            $td_import_fonts_show_update_msg = td_import_demo_style_fonts('demo_style_1');
            break;
        case 'import_style_2':
            $td_import_fonts_show_update_msg = td_import_demo_style_fonts('demo_style_2');
            break;
        case 'import_style_3':
            $td_import_fonts_show_update_msg = td_import_demo_style_fonts('demo_style_3');
            break;
        case 'import_style_4':
            $td_import_fonts_show_update_msg = td_import_demo_style_fonts('demo_style_4');
            break;
        case 'import_style_5':
            $td_import_fonts_show_update_msg = td_import_demo_style_fonts('demo_style_5');
            break;
    }
}
//import demo style fonts only
function td_import_demo_style_fonts($file_style)
{
    $explode_nr_file = explode('_', $file_style);
    //read the settings file
    $file_settings = unserialize(base64_decode(file_get_contents(get_template_directory() . '/includes/wp_booster/demo/files_cookies_settings/' . $file_style . '.txt', true)));
    //'tds_top_menu_text_color',
    //'tds_menu_text_color',
    $array_import_settings_from_file = array('tds_header_style', 'tds_header_align_top', 'tds_top_menu', 'tds_top_menu_color', 'tds_data_top_menu', 'tds_menu_icon_color', 'tds_theme_color', 'tds_site_background_color', 'tds_header_wrap_color', 'tds_logo_text_color', 'tds_menu_color', 'tds_link_color', 'tds_link_hover_color', 'tds_footer_color', 'tds_footer_text_color', 'tds_footer_bottom_color', 'tds_footer_bottom_text_color', 'tds_site_background_image', 'tds_site_background_repeat', 'tds_site_background_position_x', 'tds_site_background_attachment', 'tds_stretch_background', 'tds_transparent_header', 'tds_main_menu_transform', 'tds_big_slide_transform', 'td_body_classes');
    foreach ($array_import_settings_from_file as $import_setting_from_file) {
        if (isset($file_settings[$import_setting_from_file])) {
            td_global::$td_options[$import_setting_from_file] = $file_settings[$import_setting_from_file];