修正

frontend/ledger.html

@@ -22,7 +22,22 @@
       <tbody id="ledger-body"></tbody>
     </table>
 
-    <a href="index.html">← 試算表へ戻る</a>
+    <button
+      onclick="location.href = 'trial-balance.html'"
+      class="back-button"
+      style="
+        margin: 20px 0 0 0;
+        padding: 8px 16px;
+        background: #007bff;
+        color: white;
+        border: none;
+        border-radius: 4px;
+        cursor: pointer;
+        font-size: 14px;
+      "
+    >
+      ← 試算表に戻る
+    </button>
 
     <script src="js/api.js"></script>
     <script src="js/ledger.js"></script>