#attached property doest't work!(render array/form api) the css file style.css never get loaded when using the form api #attached properties. here is my code:

mymodule_menu() {

  $items['test'] = array (
            'title' =&gt; t('test css'),
            'page callback' =&gt; 'drupal_get_form',
            'page arguements' =&gt; array('test_attach_css'),
            'access callback' =&gt; TRUE,
            );

return $items;

}

function test_attach_css($form,$form_state) {
   $markup = '&lt;p class="test"&gt;style the font as red&lt;/p&gt;';
   $form['content']['#markup']  = $markup;
   $form['content']['#attached']['css'][] = drupal_get_path("module",       "mymodule")."/style.css";


return $form;
  }


the content of css file:

.test {

 color:red;


}
after many hours of searching and debugging for an anwser, i finally realize  it's a naming issue. you cannot name the css file as style.css. i changed the name  to custom.css,then it works as expected!