css - How to hide Bootstrap column on some pages -

i need hide "right" column in "md position" on pages (login, registration,contacts...) , extend "main" col-md-12.

my index.php

<div class="container">   <div class="row">                  <div id="main" class="col-md-9 col-xs-12">       <jdoc:include type="component" />     </div>     <div id="right" class="col-md-3 col-xs-12">       <?php if($this->countmodules('right')) : ?>        <jdoc:include type="modules" name="right" style="none" />       <?php endif; ?>     </div>   </div> </div> 

i think easiest way checking option & view in template , act based on value , example :

$app = jfactory::getapplication(); if(in_array($app->input->get('view'), array('login', 'registration') && in_array($app->input->get('option') ,array('com_users')){     echo ' <div id="main" class="col-md-12 col-xs-12">'; } else {     echo ' <div id="main" class="col-md-9 col-xs-12">'; } 

and similar check right menu

also can create menu login & registration & ... , dont add module in menu position want hide

then can check in template if there noting in position make main div full page width