Req: more visual distinction for class cards

Looking through card images, it's not always visually obvious which class a particular card is restricted to. Especially class-specific minions.

There is distinction via the colored border, but it's subtle and ambiguous, especially to new players. There's no need for that in a good UI. "It's in the tooltip" is fine for extended info, but this should be "first glance" info.

I know the design intent is to reduce visual clutter, so the word "Warrior" somewhere on every warrior card is probably ruled out. But a little icon in a corner would go a long way here.

WoW already has icon standards for all these heroes that could easily translate.