一句css代码让网站变灰

<style>
html{
      -webkit-filter: grayscale(100%);
      -moz-filter: grayscale(100%);
      -ms-filter: grayscale(100%);
      -o-filter: grayscale(100%);
         filter: grayscale(100%);
         filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3.org/2000/svg\'><filter id=\'grayscale\'><fecolormatrix type=\'ma
                        trix\' values=\'0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0 0 0 1 0\'></fecolormatrix></filter></svg>#grayscale");
         filter: progid:DXImageTransform.Microsoft.BasicImage(grayscale=1);
 }
 </style>