Thanks, that worked!
One caveat, similar to this issue, is that looking for the absence of the status-solved
class means topics from categories that don’t have Solved enabled, will also be highlighted. In our case I’ve added a second class to the selector to only target the support category:
/* Highlight unsolved topics */
.topic-list-item.category-support:not(.status-solved) {
background: rgba(255,192,203,.2);
}
Is there a more general solution, e.g. if more Solved categories exist, rather than repeating the selector?