How to know whether you are editing a page or a post?
You can use the admin_body_class hook to add your own CSS classes. For example (if you’re using Gutenberg): function pb_admin_body_class($classes) { $screen = get_current_screen(); if (!$screen->is_block_editor()) { return $classes; } $post_id = isset($_GET[‘post’]) ? intval($_GET[‘post’]) : false; $post_type = get_post_type($post_id); if ($post_type) { $classes .= $post_type; } return $classes; } add_filter(‘admin_body_class’, ‘pb_admin_body_class’);