Well, I just went and brute-forced my CSS. For the class I noted, above, it now looks like this:
Code:
div.chapquote {
/* Chapter Quote (quote at top of chapters) Styling */
display: block;
font-style: italic;
margin-left: 1.5em;
margin-right: 1.5em;
padding-left: 1.5em;
padding-right: 1.5em;
text-align: justify;
}
div.chapquote em {
font-style: normal;
}
div.chapquote i {
font-style: normal;
}
I added those em and i classes to every class I had that used
. Then, when the Calibre Editor's Check Book function complained about specificity for some very specific classes near the bottom of my CSS stylesheet, I just dragged those classes up near the top in their own "because Calibre told me so" section.
Not exactly elegant, but it works.
I've also opened an issue with EpubCheck:
https://github.com/w3c/epubcheck/issues/1765
They could very well come back and say Nesting Selectors don't work in Epubs, so that's why it errors on the & (though a more meaningful error message would be nice).