diff --git a/.ua/backlog.json b/.ua/backlog.json
index 52737c7..7fbf53f 100644
--- a/.ua/backlog.json
+++ b/.ua/backlog.json
@@ -2546,6 +2546,15 @@
       "status": "done",
       "domain": "visual",
       "notes": "迁移走 OUTLINE_TOKENS 整值精确匹配（squash 归一空白）；2 处 alpha-mid 柔和描边归 --ua-focus-outline-soft；verify 拦下暗色覆盖缺失（三个新令牌补 [data-theme=dark] 同口径覆盖）；AGENTS 审计类别数同步为十四；check 全绿"
+    },
+    {
+      "id": "g240",
+      "title": "button 增加 loading 态（既有组件打磨）",
+      "motivation": "异步提交按钮此前要业务自己拼「转圈 + 禁点 + 还原」三件事，switchButton 有 is-loading 而主按钮反而没有，口径不齐。",
+      "acceptance": "loading?: boolean | Signal<boolean>：加载中转圈（复用 ua-spin 帧体）并自动禁点，aria-busy 播报忙碌；文案位置不漂移（转圈非加载态不占位）；prefers-reduced-motion 降级为静态环；manifest/docs/demo 同步；npm run check 全绿。",
+      "status": "done",
+      "domain": "tune",
+      "notes": "loading 布尔归一为信号走同一响应式路径；disabled 口径合并为「显式禁用或加载中」（bindProp 函数式属性）；类名切换而非整棵重渲染（保焦点）；CSS 复用 .ua-spinner 类 + .ua-btn-spin 尺寸覆盖，零新增字面量；check 全绿"
     }
   ]
 }
diff --git a/.ua/iterations.log b/.ua/iterations.log
index 171e814..13bc4e0 100644
--- a/.ua/iterations.log
+++ b/.ua/iterations.log
@@ -284,3 +284,4 @@
 {"ts":"2026-10-26T21:31:07+08:00","id":"g237","result":"done","commit":"fc8c5ad","summary":"新增 kbd 键盘按键标记（组件 73→74）：键帽样式单键/组合键（+ 连接对读屏隐藏），纯令牌零字面量"}
 {"ts":"2026-10-26T21:35:34+08:00","id":"g238","result":"done","commit":"2262719","summary":"新增 highlight 关键词高亮（组件 74→75）：mark 包裹命中片段，大小写不敏感全部命中，双信号响应式联动"}
 {"ts":"2026-10-26T21:38:14+08:00","id":"g239","result":"done","commit":"5333896","summary":"焦点描边令牌化：outline 三形态收敛为 --ua-focus-outline(_inset/_soft)，audit 新增 outline-literal 第十四类，20 处迁移后基线归零"}
+{"ts":"2026-10-26T21:40:59+08:00","id":"g240","result":"done","commit":"5940519","summary":"button 增加 loading 态：转圈禁点 + aria-busy，布尔/信号双口径，reduced-motion 降级静态环"}