How can I display a search form with a different style from search bock, inside a node? I have a search block enabled at top side of my site. But I also need to display the same search form, but with different css class applied inside a node. How this can be done?
Since blocks can only go in a single region (without some messing about), I think you'll have to use code for this. You could add the form in a preprocess function in your theme's template.php file:

function MYTHEME_preprocess_node(&amp;$vars) {
  if ($vars['node']-&gt;type == 'my_node_type') {
    $form = drupal_get_form('search_form');

    $vars['search_form'] = render($form);
  }
}


Now in your node.tpl.php file, or node--content_type.tpl.php file, you'll be able to output the search form like this:

&lt;?php if ($search_form): echo $search_form; endif; ?&gt;


The default classes and ID added to the &lt;div&gt; surrounding the node will be be perfect for targeting that particular instance of the form with CSS. You can easily use developer tools/firebug to determine what selector to use.