This is a working example of customizing the Harlowe interface. I don’t know SugarCube unfortunately, but the same principles apply. Take a look at the code I use and see if there if anything different that stands out. Perhaps there is some insight to be had with the CSS.
Constructing a Persistent Interface in Harlowe
Sometimes, you need to declare the display: block;
. Sometimes the Twine engine might be overriding a CSS setting you made and you have to use !important
. All I can say is, good luck!