body {
    text-align: center;
}

.quadrado {
    text-align: center;
    width: 50px;
    background: #eee;
    display: inline-block;
    padding: 40px;
    font-size: 60px;
    margin: 5px;
    cursor: pointer;
    color: #eee;
}

.jogador, .vencedor {
    font-size: 30px;
    margin-top: 10px;
}

button {
    margin-top: 10px;
    width: 100px;
    height: 30px;
    background: #eee;
    cursor: pointer;
}

.footer {
    position: fixed;
    left: 0;
    margin-top: 2rem;
    bottom: 0;
    width: 100%;
    background-color: red;
    color: white;
    text-align: center;
}