How to hook contact form of drupal 7 for custom styling?

Question

how can I alter my contact form for adding custom classes
I am using contact form of Drupal 7 core module.

Answer 1

Or you can use hook_form_FORM_ID_alter() to get the specific contact form. hook_form_alter() will run for every form on the page.

function MYMODULE_form_contact_site_form_alter(&$form, &$form_state, $form_id) {
  $form['name']['#attributes']['class'] = array('class1', 'class2');

  $form['mail']['#attributes']['class'] = array('class1', 'class2');

  $form['subject']['#attributes']['class'] = array('class1', 'class2');

  $form['message']['#attributes']['class'] = array('class1', 'class2');

  // add class to the overall form
  $form['#attributes']['class'] = array('class1');
}

If you don't know how to use custom modules, you'd have to research that first. Dropping this function in and replacing MYMODULE with your module name will make this work.

Answer 2

It can been done by $form_id

 function MYMODULE_form_alter( &$form, &$form_state, $form_id ) {
        if( $form_id == 'contact_site_form' ){
    //PUT YOUR STYLING HERE
    }
}