VaadinFlow problems with css import(

Hi everyone.
Im try to create import(css) logical for my app, but not working:

parent{
 import parent.css
   children{
	  import children.css
           subchildren{
	        import subchildren.css
	       }
	}
}

My parent class:

@HtmlImport("styles/LeftMenu.html")//CSS
public class LeftMenu extends Div {

    public LeftMenu() {
        addClassName("LeftMenu"); //this style work for LeftMenu.class

        Client client = new Client();
        add(client.renderMenuItem());//Client
     }
}

My children class:

@HtmlImport("styles/Client.html") //this styles not applied for Client.class (not working)
public class Client {
    public static  String APP_ICON = ClientResources.appIcon;

    public Client() {
    }

    //Элемент основного меню
    public Div renderMenuItem(){
        Div menuItem = new Div();
        menuItem.addClassName("MenuItem");
        Image menuItemIcon = new Image(APP_ICON,"");
        menuItemIcon.addClassName("menuItemIcon");
        menuItem.add(menuItemIcon);

        return menuItem;
    }


}

Hello,

Must be something wrong in Client.html. What does it look like?

Do you get any errors in your browser’s console?