/* 变灰
html {
filter: grayscale(100%);
-webkit-filter: grayscale(100%);
-moz-filter: grayscale(100%);
-ms-filter: grayscale(100%);
-o-filter: grayscale(100%);
filter: url(desaturate.svg#grayscale);
filter:progid:DXImageTransform.Microsoft.BasicImage(grayscale=1);
-webkit-filter: grayscale(1);
}
body{filter:gray;}
HTML {
        FILTER: progid:DXImageTransform.Microsoft.BasicImage(grayscale=1); -webkit-filter: grayscale(1); -moz-filter: grayscale(100%); -ms-filter: grayscale(100%); -o-filter: grayscale(100%);BACKGROUND: #fff; COLOR: #000
}
BODY,DIV, DL,DT,DD,UL,OL,LI,H1,H2,H3,H4,H5,H6,PRE,CODE,FORM,FIELDSET,LEGEND,INPUT,TEXTAREA,P,BLOCKQUOTE,TH,TD{
        FILTER: gray; 
} 
 */