Add admin css sheet based on user ID(good for hiding admin menu)

admin-stylesheet

// custom admin style sheet
function my_admin_head() {
	$whodat = get_current_user_id();
	if ($whodat == 2) {
        echo '<link href="' .get_bloginfo('stylesheet_directory'). '/css/admin-menu.css" rel="stylesheet" type="text/css">';
    }
}
add_action('admin_head', 'my_admin_head');