radius trimming

Normal:

Here is some text that should fit in the box, but not entirely within the border radius. x x x x x x x x x x x. x x x x x x x x. x x x x x x x x x x x x.

overflow:hidden:

Here is some text that should fit in the box, but not entirely within the border radius. x x x x x x x x x x x. x x x x x x x x. x x x x x x x x x x x x.

background-image:

foreground image, overflow:hidden:

foreground image, overflow:visible: