Please help me HTML / CSS my menu

The Code that I need to use on the menu at the top of http:disappointed:revolutionarymindfulness.com

<nav class="header-navigation right">
<?php wp_nav_menu( array( 'theme_location' => 'main_menu','container_class' => 'menu' ) ); ?>
<div class="select-menu">
<?php ThemexInterface::renderDropdownMenu('main_menu'); ?>
<span> </span>
</div><!--/ select menu-->
</nav>