you can add infinite borders using box-shadow using css3 suppose you want to apply multiple borders on one div then code is like:
div {
border-radius: 4px;
/* #1 */
border: 5px solid hsl(0, 0%, 40%);
/* #2 */
padding: 5px;
background: hsl(0, 0%, 20%);
/* #3 */
outline: 5px solid hsl(0, 0%, 60%);
/* #4 AND INFINITY!!! (CSS3 only) */
box-shadow:
0 0 0 10px red,
0 0 0 15px orange,
0 0 0 20px yellow,
0 0 0 25px green,
0 0 0 30px blue;
}