Adding "chapter" before the chapter pulldown

I’d like to add the word “chapter” before each number in the dropdown chapter selector list.

I tried adding css code, but it doesn’t look like SAB can handle it:

ui.selector.chapter {
    font-size: 20sp;
    font-weight: bold;
    color: white;
}
ui.selector.chapter::before {
    content: 'chapter ';
}

But after I went back in, it came out as

ui.selector.chapter {
    font-size: 20sp;
    font-weight: bold;
    color: white;
    content: 'chapter ';
}

and it didn’t behave as I hoped.

Is there any other way to accomplish this?

No, sorry, this is not possible. The chapter selector is not displayed using HTML.

I did some experiment and it looks like I can change the text there by using the \cp marker. So, for example, doing a change like this would work:
'\\c (.*?)\n' > '\\c \1 \\cp Chapter \1\n'

But, obviously, that also styles the chapter numbers inside the text. Is there anyway (not using HTML) to edit the chapter number in one place (the dropdown menu) but not the other (text main text)?