There is no status class (.pinned) in this case. To target a pinned topic you need to use the id, eg
[data-topic-id="8"] {
background: #ffffc9;
}
The CSS above target the topic globally everywhere, on /latest, on /categories and on topic, see:
To target only the categories + latest page you need to add the appropriate class
.navigation-categories.categories-list [data-topic-id="8"] {
background: #ffffc9;
}
In this way the topic will be highlighted only on that page.
PS: to find the topic ID the simplest way is to open the dev console on your browser with F12:
