.clsBox {
    float: left;
    width: 40px;
    height: 40px;
    border : solid 3px black;
    margin: 5px;
    text-align: center;
    vertical-align: middle;
    -webkit-border-radius: 4px;
       -moz-border-radius: 4px;
            border-radius: 4px;

}

.clsLetter {
    font-weight : bold;
}

.clsAction {
    color: gray;
}

.clsSelected {
    font-weight : bold;
    background-color: yellow;
}