body > div:first-child {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 20px;
}

.gameBoard {
    --width: min(66vw,300px);
    width: var(--width);
    height: var(--width);
    display: grid;
    grid-template-columns: repeat(3,1fr);
    grid-template-rows: repeat(3,1fr);
    gap: 10px;
}

.boardSquare {
    border: 2px solid black;
    width: 100%;
    height: 100%;
    border-radius: 10px;
    display: flex;
    justify-content: center;
    align-items: center;

    font-size: 4.5rem;
    font-weight: 700;
}

.hidden {
    display: none;
}

dialog {
    padding: 30px;
}

.message {
    font-size: 3rem;
}