#bingo-board {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 5px;
    max-width: 400px;
    margin: 20px auto;
}
.bingo-cell {
    padding: 10px;
    background: #f4f4f4;
    text-align: center;
    border: 1px solid #ccc;
    cursor: pointer;
    user-select: none;
}
.bingo-cell.marked {
    background: #ffd700;
}
.bingo .bingo-cell.flash {
    animation: blink 0.5s infinite alternate;
}
@keyframes blink {
    from { background: #ffd700; }
    to { background: #fff700; }
}
#bingo-status {
    text-align: center;
    margin-top: 20px;
    font-weight: bold;
}