In the out of the box widget, as long as the Category has Categories underneath it as children, the + (plus) sign shows next to it, so I don't think you need to necessarily change anything in that regard.
Do all of this in a non-prod instance, preferably in an Update Set:
- While holding Left CTRL, right-click the widget and click 'Widget in editor'.
- The 'SC Categories' widget is read-only so you would need to create your own Copy of it and modify it. Click the 'hamburger' button on the far upper right and pick 'Clone "SC Categories".
- Give it a name and submit it.
- You'll then have to open your new Widget from the Widget menu on the upper left (why it doesn't open the new one by default, I have no idea).
- I think you want to modify the CSS-SCSS section:
.text-active {
color: $link-color;
border-left: 3px solid $primary;
font-weight: bold;
}
probably want to add an entry for background-color .
Guessing you'll need to play around with it to get what you're after.
And maybe this isn't the most efficient way to do it, but I've always added the widget to the screen the original was on, in order to reload it and look at it after I make changes.
