Custom drop down menu title

Site URL: http://www.diagonalconstrucciones.com/

Hi guys, 

I am have this problem and I can't figure it out!

I have a drop down menu that has two divisions:

1) Obras en construcción (contructions)

2) Obras realizadas (finished buildings)

they are both in the same drop down menu because once they are finished I pass them to the end of the list. The client wants only one drop down menu.

I want to make a visual distinction to make it more clear, whether is changing the color or adding a sign, or a line before to the title OBRAS REALIZADAS.

this is the further I got, in order to change the background color of the drop down menu, but I'm not quite there yet:

#headerNav nav .subnav, #sidecarNav nav .subnav{
  background-color: #272728;
}

Any ideas!? thank you very much!
 

Add to Home > Design > Custom CSS

.folder-toggle:after {
    content: ">>>";
    padding-left: 5px;
}