CSS背景色渐变写法兼容ie6至ie9

css3：

linear-gradient/*线性渐变*/

radial-gradient/*圆形渐变*/

.gradient{

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;}

/*兼容IE9*/