Here is the brief description of how to specify, how the nested elements are rendered in 3D space in CSS3 using the CSS3 transform-style property.
flat - Specifies that child elements will NOT preserve its 3D position.
preserve-3d - Specifies that child elements will preserve its 3D position.
initial - Sets this property to its default value.
inherit - Inherits this property from its parent element.
The transform-style property specifies how nested elements are rendered in 3D space. Note: This property must be used together with the transform property.