.cell {
    width: 80px;
    height: 80px;
    background-color: #2c3e50;
    color: white;
    font-size: 2rem;
    font-weight: bold;
    border-radius: 10px;
    transition: all 0.3s;
}

.cell:hover {
    background-color: #34495e;
}

.cell:disabled {
    background-color: #1abc9c;
    cursor: not-allowed;
}