body {
    font: 1.5em Segoe UI, Tahoma, sans-serif;
    text-align: center;
}

.row {
    width: 336px;
    margin: 0 auto;
}

.column {
    width: 76px;
    padding: 20px 0;
    float: left;
    display: block;
    margin: 2px;
    border: 2px solid aliceblue;
    border-radius: 4px;
}

.clear {
    clear: both;
}

#gridDiv {
    margin-top: 10px;
}

#gameOverDiv {
    color: red;
    visibility: hidden;
}