cssのテーブルで同一セルの文字列内の文字のサイズを変更する方法をご教授願えますか。

↑cssで文字サイズを変えるのに失敗している。回答が今日中に来ない場合、マルチポストもあり得ます。

<!DOCTYPE html>
<html lang="ja">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Station Board</title>
    <style>
        table {
            background-color: #cdefff;
            width: 640px;
            margin: 0 auto;
            border-collapse: collapse;
        }
        td {
            background-color: #00e2cf;
            vertical-align: middle;
            border: 1px solid #333;
        }
        .top-station-kan {
            font-size: 48pt;
            font-weight: 700;
            letter-spacing: 12pt;
            text-align: center;
            white-space: nowrap;
            display: flex;
            justify-content: center;
            align-items: stretch;
            height: 80px;
            margin-left: 65pt;
        }
.top-station-hiragana-roma {
    font-size: 14pt;
    font-weight: 700;
    letter-spacing: 1pt;
    text-align: center;
    white-space: nowrap;
    display: flex;
    justify-content: center;
    align-items: stretch;
    height: 40px;
    margin-left: 60pt; /* .top-station-hiragana の margin-left を修正 */
}
        .blank {
	margin:0px 10pt;        }
        .arrow-left,
        .arrow-left-3,
        .not-arrow {
            width: 2.5pt;
            text-align: left;
            vertical-align: middle;
            display: inline-block;
            box-sizing: content-box;
        }
        .arrow-right,
        .arrow-right-2,
        .not-arrow-3 {
            width: 2.5pt;
            text-align: right;
            vertical-align: middle;
            display: inline-block;
            box-sizing: content-box;
        }
        .next-hiragana,
        .previous-hiragana,
        .next-hiragana-2,
        .previous-hiragana-2,
        .next-hiragana-3,
        .previous-hiragana-3 {
            font-size: 14pt;
        }
        .next-roma,
        .previous-roma,
        .next-roma-2,
        .previous-roma-2 {
            letter-spacing: 1.5pt;
        }
        .next-hiragana,
        .next-roma,
        .next-hiragana-2,
        .next-roma-2,
        .next-hiragana-3,
        .next-roma-3 {
            text-align: left;
            display: inline-block;
            padding-left: 0;
            padding-right: 60pt;
            width: 0;
            white-space: nowrap;
            box-sizing: content-box;
        }
        .next-hiragana,
        .next-roma,
        .next-hiragana-3,
        .next-roma-3 {
           letter-spacing: 4pt ;
        }
        .next-hiragana,
        .next-roma,
        {
           letter-spacing: 4pt ;
        }
        .previous-hiragana,
        .previous-roma,
        .previous-hiragana-2,
        .previous-roma-2,
        .previous-hiragana-3,
        .previous-roma-3 {
            text-align: right;
            display: inline-block;
            padding-left: 0;
            padding-right: 47.5pt;
            width: 0;
            white-space: nowrap;
            box-sizing: content-box;
        }
        .previous-hiragana,
        .previous-roma,
        .previous-hiragana-2,
        .previous-roma-2 {
            letter-spacing: 4pt ;
        }
    </style>
</head>
<body>
    <select id="tableSelect" onchange="changeTable()">
        <option value="table1">Table 1</option>
        <option value="table2">Table 2</option>
        <option value="table3">Table 3</option>
    </select>

    <table id="table1">
        <tbody>
            <tr>
                <td colspan="4">
                    <div class="top-station-kan">森ノ宮</div>
                </td>
            </tr>
            <tr>
                <td colspan="4">
                    <div class="top-station-hiragana">もりのみや<span class="blank"></span></div><div class="top-station-roma">Morinomiya</div>
                </td>
            </tr>
            <tr>
                <td>
                    <span class="arrow-left">←</span>
                </td>
                <td class="next">
                    <span class="next-hiragana">おおさかじょうこうえん</span><br><span class="next-roma">Ōsakajōkōen</span>
                </td>
                <td class="previous">
                    <span class="previous-hiragana">おおさかじょうこうえん</span><br><span class="previous-roma">Ōsakajōkōen</span>
                </td>
                <td>
                    <span class="arrow-right">→</span>
                </td>
            </tr>
        </tbody>
    </table>

    <table id="table2" style="display: none;">
        <tbody>
            <tr>
                <td colspan="4">
                    <div class="top-station-kan">森ノ宮</div>
                </td>
            </tr>
            <tr>
                <td colspan="4">
                    <div class="top-station-hiragana-roma">もりのみや<span class="blank"></span>Morinomiya</div>
                </td>
            </tr>
            <tr>
                <td>
                    <span class="not-arrow"></span>
                </td>
                <td class="next-2">
                    <span class="next-hiragana-2">おおさかじょうこうえん</span><br><span class="next-roma-2">Ōsakajōkōen</span>
                </td>
                <td class="previous-2">
                    <span class="previous-hiragana-2">おおさかじょうこうえん</span><br><span class="previous-roma-2">Ōsakajōkōen</span>
                </td>
                <td>
                    <span class="arrow-right-2">→</span>
                </td>
            </tr>
        </tbody>
    </table>

発生している問題・分からないこと

cssのテーブルで同一セルの文字列内の文字のサイズを変更する方際に、上下方向がずれたり、文字が左揃えで、大きさが初期設定の大きさになったりします。

該当のソースコード

css
1.top-station-hiragana {
2    font-size: 14pt;
3    font-weight: 700;
4    letter-spacing: 1pt;
5    text-align: center;
6    white-space: nowrap;
7    display: flex;
8    justify-content: center;
9    align-items: stretch;
10    height: 40px;
11    margin-left: 60pt; /* .top-station-hiragana の margin-left を修正 */
12}

css
1.top-station-roma {
2    font-size: 14pt;
3    font-weight: 700;
4    letter-spacing: 1pt;
5    text-align: center;
6    white-space: nowrap;
7    display: flex;
8    justify-content: center;
9    align-items: stretch;
10    height: 40px;
11    margin-left: 60pt; /* .top-station-hiragana の margin-left を修正 */
12}