Kirki_Styles_Output_CSS::styles_parse PHP Method

        public static function styles_parse($css = array())
        {
            // Pass our styles from the kirki/styles_array filter.
            $css = apply_filters('kirki/styles_array', $css);
            // Process the array of CSS properties and produce the final CSS.
            $final_css = '';
            if (!is_array($css) || empty($css)) {
                return '';
            }
            foreach ($css as $media_query => $styles) {
                $final_css .= 'global' != $media_query ? $media_query . '{' : '';
                foreach ($styles as $style => $style_array) {
                    $final_css .= $style . '{';
                    foreach ($style_array as $property => $value) {
                        $value = is_string($value) ? $value : '';
                        $final_css .= $property . ':' . $value . ';';
                    }
                    $final_css .= '}';
                }
                $final_css .= 'global' != $media_query ? '}' : '';
            }
            return $final_css;
        }

 /**
  * loop through all fields and create an array of style definitions
  */
 public static function loop_controls()
 {
     // Get an instance of the Kirki_Styles_Output_CSS class.
     // This will make sure google fonts and backup fonts are loaded.
     Kirki_Styles_Output_CSS::get_instance();
     $fields = Kirki::$fields;
     $css = array();
     // Early exit if no fields are found.
     if (empty($fields)) {
         return;
     }
     foreach ($fields as $field) {
         // Only continue if $field['output'] is set
         if (isset($field['output']) && !empty($field['output']) && 'background' != $field['type']) {
             if (function_exists('array_replace_recursive')) {
                 $css = array_replace_recursive($css, Kirki_Styles_Output_CSS::css($field));
             } else {
                 $css = Kirki_Helper::array_replace_recursive($css, Kirki_Styles_Output_CSS::css($field));
             }
         }
     }
     if (is_array($css)) {
         return Kirki_Styles_Output_CSS::styles_parse(Kirki_Styles_Output_CSS::add_prefixes($css));
     }
     return;
 }