#shifter {border:0;border-collapse: collapse;margin:0 auto;}
#shifter tr td {min-width:12px;min-height:12px;width:20px;height:20px;border:1px solid #CCC;padding:0;margin:0;empty-cells:show; text-align: center; font-size: 12px;
    text-shadow: 0 0 1px white,1px 1px 4px white,-1px 1px 4px white,1px -1px 4px white,-1px -1px 4px white ; font-weight: bold;
    -ms-user-select: none;
    -moz-user-select: none;
    -khtml-user-select: none;
    -webkit-user-select: none;
    user-select: none;
    /*transition: all 50ms ease;*/
}

@keyframes newshadow {
    from {box-shadow: 0 0 10px blue;outline: 2px dashed red;outline-offset: -3px;}
    50% {box-shadow: 0 0 10px yellow;outline: 2px dashed green;outline-offset: -4px;}
    to {box-shadow: none;outline: none;}
}

.hintcell {
    z-index: 1000;
    animation: newshadow  1s infinite ease-in-out;
}