CSS change style of last element

[Bavacrete]

In wordpress template I have navigation meniu \[code\]<nav id="main-menu"> <?php $home_url = home_url(); $menu = wp_nav_menu(array('theme_location' => 'main', 'menu_id' => 'menu', 'echo' => false, 'menu' => 'LT')); $menu = str_replace('#HOME_URL', $home_url, $menu); echo $menu; ?></nav>\[/code\]I want that last of menu link will be red I try this \[code\]ul#main-menu li a:last-child{color: red;}\[/code\]but it not work.