body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    font-family: Arial, sans-serif;
    background: linear-gradient(135deg, #6e8efb, #a777e3);
}

.container {
    text-align: center;
}

h1 {
    font-size: 2rem;
    margin-bottom: 20px;
    color: #fff;
}

.board {
    display: grid;
    grid-template-columns: repeat(3, 100px);
    grid-template-rows: repeat(3, 100px);
    gap: 10px;
}

.cell {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100px;
    height: 100px;
    background-color: #fff;
    border: 2px solid #000;
    font-size: 2rem;
    cursor: pointer;
}

button {
    margin-top: 20px;
    padding: 10px 20px;
    font-size: 1rem;
    cursor: pointer;
}

.message-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center;
}

.message-content {
    background: #fff;
    padding: 20px;
    text-align: center;
    border-radius: 10px;
}

.message-content h2 {
    margin-bottom: 20px;
}

.hidden {
    display: none;
}

@media (max-width: 600px) {
    .board {
        grid-template-columns: repeat(3, 80px);
        grid-template-rows: repeat(3, 80px);
    }

    .cell {
        width: 80px;
        height: 80px;
        font-size: 1.5rem;
    }

    h1 {
        font-size: 1.5rem;
    }
}