#grad2 {

     height: 440px;

     width: 440px;

     border-radius: %;

     background: -webkit-radial-gradient(closest-corner,rgba(,,,0.9)%,rgba(,,,0.8)%,rgba(,,,0.6)%,rgba(,,,0.4)%,rgba(,,,0.2)%); /* Safari 5.1 - 6.0 */

     background: -o-radial-gradient(closest-corner,rgba(,,,0.9)%,rgba(,,,0.8)%,rgba(,,,0.6)%,rgba(,,,0.4)%,rgba(,,,0.2)%); /* Opera 11.6 - 12.0 */

     background: -moz-radial-gradient(closest-corner,rgba(,,,0.9)%,rgba(,,,0.8)%,rgba(,,,0.6)%,rgba(,,,0.4)%,rgba(,,,0.2)%); /* Firefox 3.6 - 15 */

     background: radial-gradient(closest-corner,rgba(,,,0.9)%,rgba(,,,0.8)%,rgba(,,,0.6)%,rgba(,,,0.4)%,rgba(,,,0.2)%); /* 标准的语法（必须放在最后） */

        /* Firefox 3.6+ */

      background: -moz-radial-gradient(circle, #ace, #f96);

      /* Safari 4-5, Chrome 1-9 */

      /* Can't specify a percentage size? Laaaaaame. */

      background: -webkit-gradient(radial, center center, , center center, , from(#ace), to(#f96));

      /* Safari 5.1+, Chrome 10+ */

      background: -webkit-radial-gradient(circle, #ace, #f96);

 }