Li width not working

[admin]

Trying to show words inside wordpress menu item in column, by limiting its width. Can't make it work.
I tried "width:", i tried "max-width:", added "!important". I tried putting it into li, and i tried putting it into li a. Nothing works.

live link here
<a href="http://soloveich.com/pr2-2/" rel="nofollow">http://soloveich.com/pr2-2/</a>

html code

<div id="mainpage2">
<ul>
    <li>
    <?php wp_nav_menu( array( 'theme_location' => 'main-menu'  ) ); ?>
</ul>
</li>
</div>

and css

#mainpage2 ul {
    list-style: none;
}

#mainpage2 ul li {
    display: inline;
}

#mainpage2 ul li a {
    max-width: 200px;
    font-size: 40px;
    font-weight: bold;
    text-align: center;
    font-family: verdana;
    color: #fff;
}