Question Make frames cornerradius go outwards instead of inwards

[Martimus]

Hello there guys

Does any of you have a nice hack for changing my frames corner radius to go outwards instead of inwards? Please take a look at my attached picture.
Im trying to make the lines add up instead of breaking at the corner edges because it cant bend the other way

 

[Martimus]

Nobody who have gotten any ideas as to how to make this happen? Perhaps some custom css?