.title
{
    text-align: center;
    font-size: 30px;
}

.square
{
    position: absolute;
    background-color: lightgrey;
}

.square:hover, .square.possible:hover
{
    background-color: lightblue;
}

.square.possible
{
    background-color: lightgreen;
}

#response {
    font-size: 14px;
}