chore(ui): Make button group responsive in task table (#2781)

Author: KATO-Hiro

docs/dev-notes/2025-11-02/make-button-group-responsive/plan.md

@@ -0,0 +1,61 @@
+# Button Group のレスポンシブ化
+
+## 問題
+
+640px未満の画面でボタングループの文字が縦に潰れてしまう
+
+## 解決方法
+
+Tailwind CSSのレスポンシブクラスを使用してボタンの折り返しと配置を実装
+
+## コード変更
+
+### 修正前
+
+```svelte
+<ButtonGroup class="m-4 contents-center">
+```
+
+### 修正後
+
+```svelte
+<div class="flex justify-center m-4">
+  <ButtonGroup class="flex flex-wrap justify-start gap-1">
+    {#each Object.entries(contestTableProviderGroups) as [type, config]}
+      <Button
+        onclick={() => updateActiveContestType(type as ContestTableProviderGroups)}
+        class={`rounded-lg ${activeContestType === (type as ContestTableProviderGroups)
+          ? 'active-button-class text-primary-700 dark:!text-primary-500'
+          : ''}`}
+        aria-label={config.getMetadata().ariaLabel}
+      >
+        {config.getMetadata().buttonLabel}
+      </Button>
+    {/each}
+  </ButtonGroup>
+</div>
+```
+
+## 使用クラス一覧
+
+| クラス           | 役割                                        |
+| ---------------- | ------------------------------------------- |
+| `flex`           | Flexboxコンテナを有効化                     |
+| `flex-wrap`      | 画面幅に応じてボタンを折り返す              |
+| `justify-center` | ボタングループ全体を水平中央揃え（外側div） |
+| `justify-start`  | ボタン自体を左寄せ（ButtonGroup内）         |
+| `gap-1`          | ボタン間のスペーシング（0.25rem）           |
+| `rounded`        | ボタンの角に丸みを付与                      |
+
+## 参考資料
+
+- [Tailwind CSS - Flex Wrap](https://tailwindcss.com/docs/flex-wrap)
+- [Tailwind CSS - Justify Content](https://tailwindcss.com/docs/justify-content)
+- [Tailwind CSS - Gap](https://tailwindcss.com/docs/gap)
+- [Tailwind CSS - Border Radius](https://tailwindcss.com/docs/border-radius)
+
+## 使用ライブラリ
+
+- Tailwind CSS
+- Flowbite
+- svelte-5-ui-lib

src/lib/components/TaskTables/TaskTable.svelte

@@ -171,19 +171,23 @@
 
 <!-- See: -->
 <!-- https://flowbite-svelte.com/docs/components/button-group -->
-<ButtonGroup class="m-4 contents-center">
-  {#each Object.entries(contestTableProviderGroups) as [type, config]}
-    <Button
-      onclick={() => updateActiveContestType(type as ContestTableProviderGroups)}
-      class={activeContestType === (type as ContestTableProviderGroups)
-        ? 'active-button-class text-primary-700 dark:!text-primary-500'
-        : ''}
-      aria-label={config.getMetadata().ariaLabel}
-    >
-      {config.getMetadata().buttonLabel}
-    </Button>
-  {/each}
-</ButtonGroup>
+<div class="flex justify-center m-4">
+  <ButtonGroup class="flex flex-wrap justify-start gap-1">
+    {#each Object.entries(contestTableProviderGroups) as [type, config]}
+      <Button
+        onclick={() => updateActiveContestType(type as ContestTableProviderGroups)}
+        class={`rounded-lg ${
+          activeContestType === (type as ContestTableProviderGroups)
+            ? 'active-button-class text-primary-700 dark:!text-primary-500'
+            : ''
+        }`}
+        aria-label={config.getMetadata().ariaLabel}
+      >
+        {config.getMetadata().buttonLabel}
+      </Button>
+    {/each}
+  </ButtonGroup>
+</div>
 
 <!-- TODO: ページネーションを実装 -->
 <!-- See: -->