Changing hover color for secondary navigation button (7.0-Brine, Nueva template)

I have one button (solid, rounded) under secondary navigation. I want the color of the button to change when a cursor hovers over it. I am using Version 7.0 - Brine (Nueva template). I understand that I will need to input this code into the Custom CSS section, but I am not sure what code to use. Any help is appreciated. Thanks!

I've since found the answer to this question. Insert the following into the Custom CSS section, which you can find at the bottom of the Design sidebar:

.Header-nav-item[href="/slug"]:hover {
    background: #ffffff !important;
  color: #ffffff !important;
}

This solution assumes the button links to another page associated with your site. Replace "slug" with the destination URL slug, and enter the hex codes for the background color ("background") and text color ("color") you want to see with a cursor hover.