Navigation menu Lite Dropdown indicator not considered

First of all, thank you for the great plugin! Maybe you can help me with my problem:

I’m using navigation menu lite, a vertical menu with vertical dropdown submenus. I have the background width automatically set to the length of the menu link with this CSS:
.plus-navigation-menu .navbar-nav li a, .plus-navigation-menu.menu-vertical .nav li.dropdown .dropdown-menu > li a {
display: inline-block;
}

BUT the dropdown indicator is not included in the width. How can I have the indicator reciognized as part of the width as well?