You can do this in modern browsers now using transform 3D with CSS. It wasn’t really possible in 2010 but it is now.
.parent {
background: red;
width: 100px;
height: 100px;
transform-style: preserve-3d;
position: relative;
}
.child {
background: blue;
width: 100px;
height: 100px;
position: absolute;
top: -5px;
left: -5px;
transform: translateZ(-10px)
}
<div class="parent">
Parent
<div class="child">
Child
</div>
</div>