How can Joomla isis template be forced to display dropdown menu icons?

Question

Various 3rd party extensions have dropdown menu icons that don't appear in ISIS because ISIS doesn't provide for dropdown menu icons. This is caused because ISIS has the following CSS activator.

.nav-collapse .nav li a,
.dropdown-menu a {
    background-image: none;
}

I've determined that if that activator is commented out in the template.css file the 3rd party menu icons appear.

The problem is that every time Joomla has an upgrade, the ISIS template upgrade will over write the template.css file. The ISIS template provides for the addition of a custom.css file which loads after the template's default CSS file.

What code should be placed in the custom.css file to provide for the display of the 3rd party dropdown menu icons? I've tried the following code in custom.css, but it doesn't work.

.nav-collapse .nav li a,
.dropdown-menu a {
    /* background-image: none; */
}

Any ideas would be appreciated.

Answer 1

I'd try this:

.nav-collapse .nav li a, .dropdown-menu a {background-image: inherit;}