I’m pretty sure that’s where you’d use roles. For example, in my CSS I have this:
.anvil-role-scrollable-cart
{
max-height: 55vh;
overflow-y: scroll;
}
Then I set the role for a repeating panel like this:
self.repeating_panel_1.role='scrollable-cart'
That causes the repeating panel to pick up that CSS. There are more examples in the forums that I used to put that together.