(Genesis WordPress) Post Category Widget Icons

style.css

/*
Floating custom icons to the left of post category names in
the post category widget. The category item has a number
associated with it that can be found through the developer
tools in your console. This number will replace the ?? in
the CSS. The current CSS works best with icons that are
50px square. It can be adjusted depedning on the icon size.
*/

/* ## Entries
--------------------------------------------- */

/*Post Categories*/
.cat-item-?? {
  background: url(images/icon.png) left no-repeat;
  background-size: 30px 30px;
  padding: 15px 40px;
}