#game-board {
    display: grid;
    grid-template-columns: repeat(9, 30px); /* 9 columns with 30px width */
    grid-gap: 1px;
    border: 1px solid black;
}

.cell {
    width: 30px;
    height: 30px;
    border: 1px solid #ccc;
    text-align: center;
    vertical-align: middle;
    font-size: 20px;
    cursor: pointer;
}

.cell:hover {
    background-color: #eee;
}

.revealed {
    background-color: #ddd;
    cursor: default;
}

.mine {
    background-color: red;
    color: white;
}