Wordpress Multisite add site id and page slug to body class

functions.php

// Add site-id to body class to allow site-specific styling in a central style.css file
// (this code goes in your theme's functions.php or in a site-specific plugin)

function site_id_in_body_class($classes) {
        $this_id = get_current_blog_id();
        $classes[] = 'site-id-'.$this_id;
        return $classes;
}
add_filter('body_class', 'site_id_in_body_class');

// Add page slug to body class to allow page-specific styling
// based on: http://timneill.net/2013/05/wordpress-add-page-slug-to-body-class-including-parents/

function page_slug_in_body_class($classes) {
    // You can modify this check so it will run on every post type
    if (is_page()) {
        global $post;
        
        // If we *do* have an ancestors list, process it
        // http://codex.wordpress.org/Function_Reference/get_post_ancestors
        if ($parents = get_post_ancestors($post->ID)) {
            foreach ((array)$parents as $parent) {
                // As the array contains IDs only, we need to get each page
                if ($page = get_page($parent)) {
                    // Add the current ancestor to the body class array
                    $classes[] = "{$page->post_type}-{$page->post_name}";
                }
            }
        }
 
        // Add the current page to our body class array
        $classes[] = "{$post->post_type}-{$post->post_name}";
    }
    
    return $classes;
}
add_filter('body_class', 'page_slug_in_body_class');