body {
    font-family: Arial, sans-serif;
    text-align: center;
    background-color: #f0f0f0;
    margin: 0;
    padding: 0;
}

.container {
    margin: 0 auto;
    padding: 20px;
    width: 300px;
    background-color: #fff;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    border-radius: 10px;
    margin-top: 50px;
}

h1 {
    margin-bottom: 20px;
}

#tic-tac-toe-board {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 5px;
    margin-bottom: 20px;
}

.cell {
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid #333;
    font-size: 24px;
    cursor: pointer;
    background-color: #eee;
    user-select: none;
}

button {
    padding: 10px 20px;
    font-size: 16px;
    cursor: pointer;
    background-color: #333;
    color: #fff;
    border: none;
    border-radius: 5px;
    transition: background-color 0.3s;
}

button:hover {
    background-color: #555;
}