when all corners are the same, it’s pretty straightforward:

but standard CSS shorthand can be inconsistent, because the draft specifies two values for the property (one for each axis of the curve).

* mozilla “opted out”, and doesn’t allow irregular curves, but does allow shorthand.

when setting individually, again mozilla is the exception. for webkit, konqueror and standards, it’s:


but mozilla wants it like so:


so… for all corners:

and for individual corners: