Possible to customize the look/length of CKEditor Styles dropdown? I've added custom styles to the Styles dropdown in CKEditor included by default in Drupal 8. They work fine. However, the dropdown isn't convenient for editors to use because


It isn't tall enough
There's a lot of vertical spacing between items
Items have the style they represent, taking even more space


Here's a snip of my default Styles dropdown:



It's fine that the items have the style they represent, except it can take a lot of space in the very small box, especially if the font is large. Plus there's lots of vertical spacing between items.

I've figured a [hackish] way to keep the items from taking on their represented style, producing this:



But it's still too short with a lot of space between items, so only four styles of 20 show.

QUESTION: 

Is there a way to customize the look of the Styles dropdown, or at least to make it longer? Lots of reading of posts and documentation hasn't provided an answer, if there is one.
After a good bit of trial and error (I'm slow, but persistent), I've figured out the classes to modify the height and item styles in the CKEditor Styles dropdown. Here's an example using values that work for me:

div.cke_combopanel {
  height: 300px !important;
}
li.cke_panel_listItem a {
  padding: 3px 5px !important;
  font-size: .8em !important;
}


The div and li prefixes aren't required; I've included them here simply to identify the element types involved. Setting a fixed height for cke_combopanel is an imperfect solution, but better than the short one I get by default.