CSS3 box-shadow on left and right sides only

It is possible to have inset shadows on both left and right sides of a block. It is a matter of showing only one side of the box-shadow at a time, and so you need two box-shadows (one for each side of the block you wish to have shadows, and we can put both CSS codes in the same property).

Here is an example that should be compatible with Firefox, Chrome and Opera.

box {
    -moz-box-shadow:
        inset 5px 0 5px -5px #333,
        inset -5px 0 5px -5px #333;
    -webkit-box-shadow:
        inset 5px 0 5px -5px #333,
        inset -5px 0 5px -5px #333;
    box-shadow:
        inset 5px 0 5px -5px #333,
        inset -5px 0 5px -5px #333;
}

Here is the result:

Lorem ipsum…

Inspired from Playing with CSS3 box shadow [demente-design.com]