Most of the styles intended for the sidebar are not being applied

The side navigation has a "side_nav" class, but the CSS assumes it has a "side_nav" id.

page.tpl.php defines the side navigation as class "side_nav":

<div class="side_nav">
    <?php print $sidebar_left ?>
</div>

However, style.css tries to apply styles to an element with id "side_nav":

#side_nav ul.menu {
    margin: 0.35em 0 0 -0.5em;
    padding: 0;
}

The patch converts all of the "side_nav" in the CSS to apply to a class instead of id.