Alter jQuery UI css in drupal

gistfile1.php

<?php

/**
 * Implements hook_css_alter().
 */
function yourtheme_css_alter(&$css) {
  // Do not use jQuery UI defaults
  $yourtheme = drupal_get_path('theme', 'yourtheme');
  foreach(array('theme', 'tabs', 'accordion') as $file) {
    if (isset($css['misc/ui/jquery.ui.'.$file.'.css'])) {
      $css['misc/ui/jquery.ui.'.$file.'.css']['data'] =  $yourtheme . '/css/jquery_ui/jquery.ui.'.$file.'.css';
    }
  }

}