Style a wp_list_category

Hello forumers !

Tittle says it all. What I’m looking for is to float left all the categories in a div that is inside of the header, but I don’t find how to.

The code is:

<header id="branding" role="banner">
            <div id="logoContainer">
			sadfsdfsadfsa

            </div>
            <div id="navCategories">

                        <?php wp_list_categories('exclude=500&title_li='); ?>

				<!--<h1 id="site-title"><span class="linkKram"><a href="<?php echo esc_url( home_url( '/' ) ); ?>" title="<?php echo esc_attr( get_bloginfo( 'name', 'display' ) ); ?>" rel="home"><?php bloginfo( 'name' ); ?></a></span></h1>
				<h2 id="site-description"><?php bloginfo( 'description' ); ?></h2>-->

            </div>

An image: Image

Thanks in advance for your replies and time ?? !