How to format my main navigation window

I created two menus and added custom code to my header.php to open either menu based on if the user is logged in or not. But when i added the custom code, it changed the format of my navigation making the buttons smaller. I want to still use the format of the original theme settings, but can’t figure out how. Here is the section of code that i added to my header.php below:

<nav id=”access” role=”navigation”>

<?php
if( is_user_logged_in() ) {
$menu = ‘logged-in’;
} else {
$menu = ‘logged-out’;
}
wp_nav_menu( array( ‘menu’ => $menu, ‘container_class’ => ‘menu-header’, ‘theme_location’ => ‘primary’ ) );
?>

</nav><!– #access –>

I have tried all sorts of things with thew style.css file, but nothing seems to work. Can someone direct me in what i need to do to make this work