/**
  * loop through all fields and create an array of style definitions
  */
 public static function loop_controls()
 {
     $fields = Lessekirki::$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, Lessekirki_Styles_Output_CSS::css($field));
             } else {
                 $css = Lessekirki_Helper::array_replace_recursive($css, Lessekirki_Styles_Output_CSS::css($field));
             }
         }
     }
     if (is_array($css)) {
         return Lessekirki_Styles_Output_CSS::styles_parse(Lessekirki_Styles_Output_CSS::add_prefixes($css));
     }
     return;
 }