It is, but the way border-radius applies values is weird.  [From this post](http://css-tricks.com/almanac/properties/b/border-radius/), here's how border radius args are interpreted:

> If one value is set, this radius applies to all 4 corners.
> If two values are set, the first applies to top-left and bottom-right corner, the second applies to top-right and bottom-left corner.
> Four values apply to the top-left, top-right, bottom-right, bottom-left corner in that order.
> Three values: The second value applies to top-right and also bottom-left.