Add Class Body Multisite / Adicionando Classe Body para Multisite

add_body_class_wpmu.php

<?php
// Apply filter
add_filter('body_class', 'multisite_body_classes');

function multisite_body_classes($classes) {
        $id = get_current_blog_id();
        $slug = strtolower(str_replace(' ', '-', trim(get_bloginfo('name'))));
        $classes[] = sanitize_title('site-'.$slug);
        return $classes;
}