feat(前端界面): 优化确认框布局与按钮对齐

assets/webui/index.html

@@ -186,10 +186,10 @@
 				<button id="batchPagesButton" class="editor-group-action" type="button">页面</button>
 			</div>
 		</div>
-		<dialog id="closePanel" class="form-dialog">
+		<dialog id="closePanel" class="form-dialog confirm-dialog">
 			<form method="dialog">
 				<h2 class="form-title">关闭文档</h2>
-				<div class="form-row">文档尚未保存</div>
+				<p class="confirm-message">文档尚未保存</p>
 				<div class="form-actions"><button class="button" value="cancel" autofocus>取消</button><button class="button" value="discard">放弃</button><button class="button" value="save">保存</button></div>
 			</form>
 		</dialog>

assets/webui/ofdgo.css

@@ -805,6 +805,16 @@ button:not(:disabled):hover {
 	line-height: 1.5;
 }
 
+.confirm-message {
+	margin: 0 0 16px;
+	line-height: 1.5;
+}
+
+.confirm-dialog .form-actions {
+	grid-template-columns: repeat(3, max-content);
+	justify-content: end;
+}
+
 .convert-dialog {
 	--convert-control-width: 64px;
 	width: 720px;