Link second navigation to css

Hi everyone,

Ive been trying to add a second navigation bar.
I already can see it, but I was wondering What do I have to do, to create a new css part where the php is linking to.
right now I have this in the header

<nav id=”site-navigation” class=”second-navigation” role=”navigation”>
<h3 class=”menu-toggle”><?php _e( ‘Menu’, ‘twentytwelve’ ); ?></h3>
“><?php _e( ‘Skip to content’, ‘twentytwelve’ ); ?>
<?php wp_nav_menu( array( ‘theme_location’ => ‘second’, ‘menu_class’ => ‘nav-menu’ ) ); ?>
</nav><!– #second-navigation –>

the website is naruto-naruto.com