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