Here is the final spec:
| new appearance | behavior | old appearance |
|---|---|---|
| columns | horizontal labels with buttons arranged in a number of columns determined by the screen width | horizontal |
| columns no-buttons | horizontal labels without buttons arranged in a number of columns determined by the screen width | |
| columns-pack | horizontal labels with buttons, packed in to fit horizontal space with minimal padding | horizontal-compact |
| columns-pack no-buttons | horizontal labels without buttons, packed in to fit horizontal space with minimal padding | compact |
| columns-n | horizontal labels with buttons arranged in n columns where n is an integer between 1 and 10 inclusive | |
| columns-n no-buttons | horizontal labels without buttons arranged in n columns where n is an integer between 1 and 10 inclusive | compact-n |