In halo theme, when I create a menu in web menu left sidebar and items in that menu, upon expanding the menu there is just a thin line separator and 1 can’t tell that these items belong to this menu. Even when collapsed, 1 can’t distinguish between 1st level menus and 1st level items.
My idea to add a certain amount of indentation to submenu items and a +/- sign against menus depending on whether is collapsed/expanded respectively.