Clara BW Changing the font in epub Table of Contents?

[Krytes]

Sorry for the multiple questions, still slowly trying to get my new Clara BW set up to my liking. Is there a way to change the default font used for the "Table of Contents" entries in an epub? Whatever's being used right now is missing a lot of Chinese characters, so the table of contents in a Chinese book becomes an unreadable mess full of crossed-out boxes.

The same problem was happening with the header/footer text. I used the kobopatch "Custom header/footer captions" with the line

- {Find: "font-family: DefaultSansSerif;", Replace: "font-family: 'AR UDJingxihei'; background:transparent;"}

which worked beautifully on my header/footer text. I was hoping that maybe the table of contents was using DefaultSerif and tried adding the line

- {Find: "font-family: DefaultSerif;", Replace: "font-family: 'AR UDJingxihei';"}

but that crashed so badly that I had to factory reset.

Is there another way to get a readable Table of Contents without changing my entire localization to Chinese?