#board {
    display: inline-block;
    border-collapse: separate;
    border-spacing: 4px;
}
.board-row {
    display: table-row;
}
.board-cell {
    display: table-cell;
    width: 35px;
    height: 35px;
    line-height: 35px;
    border: 1px solid black;
    border-radius: 5px;
    font-size: 24px;
    text-align: center;
}
.board-cell.selected {
    background-color: #FFD23B;
}
.board-cell.current {
    background-color: #FF8A39;
}