<basic-shape>
<basic-shape>
The <basic-shape> type can be specified using basic shape functions. When using this syntax to define shapes, the reference box is defined by each property that uses <basic-shape> values. The coordinate system for the shape has its origin on the top-left corner of the reference box with the x-axis running to the right and the y-axis running downwards. All the lengths expressed in percentages are resolved from the used dimensions of the reference box.
Possible shapes
The following shapes are supported. All <basic-shape> values use functional notation and are defined here using the value definition syntax.
inset()-
inset( <shape-arg>{1,4} [round <border-radius>]? )Defines an inset rectangle.