Thanks, I added:
.topic-card.has-max-height {
background: #e6ecf2
}
.topic-card.has-max-height:hover {
background: #ddecf7
}
And it works perfectly with stock ‘Shades of Blue’ palette.
Alright, part 2. How do I edit it to work with 2 color palettes? Looked good till the browser switched to dark mode.
Answering my own question again…
I learned about @media (prefers-color-scheme: light/dark)
last night, so all good.