function plt_hide_custom_css_menus() {
//Hide the "Tools → Custom CSS" menu.
remove_submenu_page('tools.php', 'alg-custom-css');
//Hide the "Tools → Custom JS" menu.
remove_submenu_page('tools.php', 'alg-custom-js');
//Hide the "Tools → Custom PHP" menu.
remove_submenu_page('tools.php', 'alg-custom-php');
}
add_action('admin_menu', 'plt_hide_custom_css_menus', 11);