body {
    background: #0f172a;
    color: white;
    font-family: Arial, sans-serif;
    text-align: center;
}

.game-container {
    margin-top: 40px;
}

.grid {
    display: grid;
    gap: 5px;
    justify-content: center;
    margin: 20px auto;
}

.cell {
    width: 60px;
    height: 60px;
    background: #1e293b;
    cursor: pointer;
    border-radius: 6px;
    transition: 0.2s;
}

.cell.active {
    background: #22c55e;
}

button {
    padding: 10px 20px;
    background: #22c55e;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-weight: bold;
}