body {
    font-family: Arial, sans-serif;
    text-align: center;
    margin: 20px;
}
table {
    margin: 20px auto;
    border-collapse: collapse;
}
.cell {
    width: 60px;
    height: 60px;
    border: 1px solid #000;
    text-align: center;
    vertical-align: middle;
}
.empty-cell {
    width: 100%;
    height: 100%;
    background: transparent;
    border: none;
    font-size: 24px;
    cursor: pointer;
}
.empty-cell:hover {
    background: #f0f0f0;
}
.x,
.o {
    font-size: 24px;
    font-weight: bold;
    color: black;
}
.error {
    color: red;
    font-weight: bold;
    margin: 10px 0;
}
#status {
    font-size: 18px;
    font-weight: bold;
    margin-top: 10px;
}