html页面变灰css代码

添加以下Css代码即可：

html {
    -webkit-filter: grayscale(100%);
    -moz-filter: grayscale(100%);
    -ms-filter: grayscale(100%);
    -o-filter: grayscale(100%);
    filter: grayscale(100%);
    filter: gray;
filter:progid:DXImageTransform.Microsoft.BasicImage(grayscale=1);
}