css3 寫漸變背景

 參考：http://caibaojian.com/css3-background-gradient.html

.b-box{
    background: #000000;
    background: -moz-linear-gradient(top,  #000000 0%, #ffffff 100%);
    background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#000000), color-stop(100%,#ffffff));
    background: -webkit-linear-gradient(top,  #000000 0%,#ffffff 100%);
    background: -o-linear-gradient(top,  #000000 0%,#ffffff 100%);
    background: -ms-linear-gradient(top,  #000000 0%,#ffffff 100%);
    background: linear-gradient(to bottom,  #000000 0%,#ffffff 100%);
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#000000', endColorstr='#ffffff',GradientType=0 );
}
:root .gradient{filter:none;}