body, html{
   margin:0;
   padding:0;
}
div#sudoku{
   text-align:center;
}
#sudoku table{
   border:3px solid #000;
   margin:0px auto;
   empty-cells:show;
}
#sudoku td.borderright{
   border-right:3px solid #000;
}
#sudoku td.borderbottom{
   border-bottom:3px solid #000;
}
#sudoku td.borderbottomright{
   border-bottom:3px solid #000;
   border-right:3px solid #000;
}
#sudoku td{ 
   width:36px; 
   line-height:36px;
   height:36px;
   color:#4e5661;
   font-size: 26px;
   font-weight: bold;
   font-family: verdana, geneva, arial, helvetica, sans-serif;
   text-align:center;
   background:none;
   position:relative;
   border:1px solid #000;
}
#sudoku input{
   cursor:default;
   width:30px;
   margin:0;
   padding:0;
   font-size: 26px;
   font-weight: bold;
   font-family: verdana, geneva, arial, helvetica, sans-serif;
   text-align:center;
   background:none;
   border:none;
}
.knopf{  
   margin:2px;
   width:105px;
   font-family: verdana, geneva, arial, helvetica, sans-serif;
   text-align:center;
}