3D Box Shadow effect

Question

So I know how to do a basic box shadow with CSS3. You can see that in the top of the graphic below.

The effect I\'m trying to achieve is a 3D box shadow, as shown in

Answer 1

You can stack the horizontal/vertical offsets of several box-shadows, each slightly bigger than the previous one. The more shadows you add, the more pronounced the effect. Here is a fiddle example.

div {
    background: black;
    height: 100px;
    width: 100px;
    box-shadow:  0 01px gray,
                 01px 0 gray,
                 01px 02px gray,
                 02px 01px gray,
                 02px 03px gray,
                 03px 02px gray,
                 03px 04px gray,
                 04px 03px gray,
                 04px 05px gray,
                 05px 04px gray,
                 05px 06px gray,
                 06px 05px gray;
}