diff --git a/src/components/task/TaskCard.jsx b/src/components/task/TaskCard.jsx
index 9f3a781..a609c81 100644
--- a/src/components/task/TaskCard.jsx
+++ b/src/components/task/TaskCard.jsx
@@ -1,6 +1,7 @@
 import StatusDot from './StatusDot.jsx'
 import Avatar from './Avatar.jsx'
 import { kindColor } from '../../pages/task/kind.js'
+import { taskShortId } from '../../pages/task/date.js'
 
 // 看板卡片 (T-UI-02): 轻量化
 //   - 标题 + 状态点 (T-ST-09)
@@ -9,11 +10,13 @@ import { kindColor } from '../../pages/task/kind.js'
 const MAX_SUB = 3
 
 export default function TaskCard({
-  task, codePrefix, bindDrag, onClick, onToggleSub, onToggle, onMore, dragging = false, highlight = false,
+  task, bindDrag, onClick, onToggleSub, onToggle, onMore, dragging = false, highlight = false,
 }) {
   const children = task.children || []
   const shown = children.slice(0, MAX_SUB)
   const rest = children.length - shown.length
+  // 编号只显示 `#序号`; 完整编号 (项目编号-序号) 放详情页 (见 TaskDetail)
+  const shortId = taskShortId(task)
 
   return (
     <div
@@ -47,9 +50,7 @@ export default function TaskCard({
         </div>
 
         <div className="bmeta">
-          {codePrefix && task.number != null && (
-            <span className="num-tag">{codePrefix}-{task.number}</span>
-          )}
+          {shortId && <span className="num-tag">{shortId}</span>}
           {task.markDate && (
             <span className="date-tag">{task.markDate.slice(5, 10).replace('-', '/')}</span>
           )}
diff --git a/src/components/task/TaskRow.jsx b/src/components/task/TaskRow.jsx
index 9bddf99..53880db 100644
--- a/src/components/task/TaskRow.jsx
+++ b/src/components/task/TaskRow.jsx
@@ -1,6 +1,7 @@
 import StatusDot from './StatusDot.jsx'
 import Avatar from './Avatar.jsx'
 import { kindColor } from '../../pages/task/kind.js'
+import { taskShortId } from '../../pages/task/date.js'
 
 const statusLabel = (s) => (s === 'done' ? '完成' : s === 'doing' ? '执行中' : '未开始')
 
@@ -10,9 +11,11 @@ const statusLabel = (s) => (s === 'done' ? '完成' : s === 'doing' ? '执行中
 //   复选框 / ⋯ 是独立控件: pointerdown 不冒泡, 不发起拖动,
 //   避免长按行后抬手时合成的 click 落在控件上误触状态切换
 export default function TaskRow({
-  task, codePrefix, onToggle, onClick, onMore, bindDrag, bindDragHandle, dragging = false, dragOver, indent = false, children,
+  task, onToggle, onClick, onMore, bindDrag, bindDragHandle, dragging = false, dragOver, indent = false, children,
 }) {
   const done = task.status === 'done'
+  // 编号只显示 `#序号`; 完整编号 (项目编号-序号) 放详情页 (见 TaskDetail)
+  const shortId = indent ? null : taskShortId(task)
   return (
     <>
       <div
@@ -52,9 +55,7 @@ export default function TaskRow({
               <div className="task-title">{task.title}</div>
               {/* 无类型/成员也保留该行, 与有标签的行等高 */}
               <div className="task-meta">
-                {codePrefix && task.number != null && (
-                  <span className="num-tag">{codePrefix}-{task.number}</span>
-                )}
+                {shortId && <span className="num-tag">{shortId}</span>}
                 {task.markDate && (
                   <span className="date-tag">{task.markDate.slice(5, 10).replace('-', '/')}</span>
                 )}
diff --git a/src/pages/task/BoardView.jsx b/src/pages/task/BoardView.jsx
index 8cc932d..a434c7b 100644
--- a/src/pages/task/BoardView.jsx
+++ b/src/pages/task/BoardView.jsx
@@ -36,7 +36,7 @@ function ScrollBody({ children }) {
 //   横向滚列; 列内独立纵向滚动, 列头固定, 滚动时右缘显示滚动条
 //   不做"拖到卡片上转子任务" —— 统一走详情页「转为子任务」
 export default function BoardView({
-  tasks, columns, codePrefix, onMoveColumn, onOpen, onToggleSub, onToggle, onMore, onQuickAdd,
+  tasks, columns, onMoveColumn, onOpen, onToggleSub, onToggle, onMore, onQuickAdd,
 }) {
   const drag = useColumnDrag({ onDrop: onMoveColumn })
 
@@ -69,7 +69,6 @@ export default function BoardView({
                 <TaskCard
                   key={t.id}
                   task={t}
-                  codePrefix={codePrefix}
                   dragging={drag.dragTask?.id === t.id}
                   bindDrag={drag.bind}
                   onClick={() => { if (!drag.dragTask && !drag.justEnded()) onOpen?.(t) }}
diff --git a/src/pages/task/ListView.jsx b/src/pages/task/ListView.jsx
index c93600c..326abff 100644
--- a/src/pages/task/ListView.jsx
+++ b/src/pages/task/ListView.jsx
@@ -7,7 +7,7 @@ import useRowDrag from '../../components/task/useRowDrag.js'
 //   换列: 行/把手拖动, 跟手浮层, 手指划到哪个分组松手就落到哪 (与看板一致)
 //   (列表只展示有任务的列, 空列需到看板视图拖入)
 export default function ListView({
-  tasks, columns, codePrefix, onToggle, onOpen, onMore, onMoveColumn, onReorder,
+  tasks, columns, onToggle, onOpen, onMore, onMoveColumn, onReorder,
 }) {
   const [collapsed, setCollapsed] = useState({})
   const drag = useRowDrag({ columns, onDrop: onMoveColumn, onReorder })
@@ -49,7 +49,6 @@ export default function ListView({
               <div key={t.id}>
                 <TaskRow
                   task={t}
-                  codePrefix={codePrefix}
                   onToggle={onToggle}
                   onClick={() => { if (!drag.justEnded()) onOpen(t) }}
                   onMore={onMore}
diff --git a/src/pages/task/ProjectView.jsx b/src/pages/task/ProjectView.jsx
index 6f13b6b..c9c995d 100644
--- a/src/pages/task/ProjectView.jsx
+++ b/src/pages/task/ProjectView.jsx
@@ -71,6 +71,13 @@ export default function ProjectView({ projectId, onProjectChanged, onProjectExit
 
   const replaceTask = (fresh) => setTasks((prev) => (prev || []).map((t) => (t.id === fresh.id ? fresh : t)))
 
+  /** 详情页保存后: 先就地替换该行, 再回源刷新 (不回源也能立刻看到编号/列变更) */
+  const handleSaved = (fresh) => {
+    if (fresh?.id) replaceTask(fresh)
+    setOpenTask(null)
+    load()
+  }
+
   /** 更新任务(列/状态/字段), 服务端裁决后以返回值为准 */
   async function updateTask(id, patch) {
     const snapshot = tasks
@@ -276,7 +283,6 @@ export default function ProjectView({ projectId, onProjectChanged, onProjectExit
           <ListView
             tasks={visibleTasks}
             columns={columns}
-            codePrefix={project?.code}
             onToggle={toggleDone}
             onOpen={(t) => setOpenTask(t)}
             onMore={openTaskMenu}
@@ -287,7 +293,6 @@ export default function ProjectView({ projectId, onProjectChanged, onProjectExit
           <BoardView
             tasks={visibleTasks}
             columns={columns}
-            codePrefix={project?.code}
             onMoveColumn={moveToColumn}
             onOpen={(t) => setOpenTask(t)}
             onToggleSub={(c) => toggleDone(c)}
@@ -301,12 +306,13 @@ export default function ProjectView({ projectId, onProjectChanged, onProjectExit
       {openTask && (
         <TaskDetail
           task={openTask}
+          projectCode={project.code}
           columns={columns}
           members={project.members || []}
           tasks={tasks || []}
           taskKinds={project.taskKinds}
           onClose={() => setOpenTask(null)}
-          onSaved={() => { setOpenTask(null); load() }}
+          onSaved={handleSaved}
           onChanged={load}
         />
       )}
diff --git a/src/pages/task/TaskDetail.jsx b/src/pages/task/TaskDetail.jsx
index fe2df7f..208a2ce 100644
--- a/src/pages/task/TaskDetail.jsx
+++ b/src/pages/task/TaskDetail.jsx
@@ -1,7 +1,7 @@
 import { useEffect, useState } from 'react'
 import { ActionSheet, Popup, Toast, DatePicker } from 'antd-mobile'
 import { taskApi } from '../../api/task.js'
-import { STATUS_OPTIONS, STATUS_LABEL } from './date.js'
+import { STATUS_OPTIONS, STATUS_LABEL, taskFullId } from './date.js'
 import { kindColor } from './kind.js'
 import { parseTimePrefix, splitTitle } from './quickAdd.js'
 import UserPicker from '../../components/task/UserPicker.jsx'
@@ -9,11 +9,35 @@ import StatusDot from '../../components/task/StatusDot.jsx'
 import useKeyboardInset from '../../hooks/useKeyboardInset.js'
 import useOverlayBack from '../../hooks/useOverlayBack.js'
 
+// 复制文本: 优先 Clipboard API (需安全上下文), 打包端 http 明文 / 旧 WebView 回落 execCommand
+async function copyText(text) {
+  try {
+    if (navigator.clipboard?.writeText) {
+      await navigator.clipboard.writeText(text)
+      return true
+    }
+  } catch { /* 继续走兜底 */ }
+  try {
+    const ta = document.createElement('textarea')
+    ta.value = text
+    ta.setAttribute('readonly', '')
+    ta.style.cssText = 'position:fixed;top:0;left:0;opacity:0;pointer-events:none'
+    document.body.appendChild(ta)
+    ta.select()
+    ta.setSelectionRange(0, text.length)
+    const ok = document.execCommand('copy')
+    document.body.removeChild(ta)
+    return ok
+  } catch {
+    return false
+  }
+}
+
 // 任务详情 (T-TK-*, T-ST-03, T-AS-05)
 //   - 状态: 三段式分段控件, 当前项高亮, 点按即切换
 //   - 看板列: ActionSheet 选择, 列/状态联动由服务端裁决 (T-BD-*)
 //   - 转为子任务 / 转为顶层任务 (T-ST-12): 从项目内顶层任务中选父任务
-export default function TaskDetail({ task, columns, members, tasks, taskKinds, onClose, onSaved, onChanged }) {
+export default function TaskDetail({ task, projectCode, columns, members, tasks, taskKinds, onClose, onSaved, onChanged }) {
   const [form, setForm] = useState(() => ({
     title: task.title || '',
     description: task.description || '',
@@ -38,8 +62,25 @@ export default function TaskDetail({ task, columns, members, tasks, taskKinds, o
 
   const assigneeName = members.find((m) => m.userId === form.assigneeId)?.name
   const memberNames = members.filter((m) => form.memberIds.includes(m.userId)).map((m) => m.name)
-  const currentCol = (columns || []).find((c) => c.id === task.columnId)
+  const currentCol = (columns || []).find((c) => String(c.id) === String(task.columnId))
   const isSubtask = task.parentId != null
+  // 完整任务编号 (项目编号-序号), 点按复制; 未定号 (离线新建未上行) 不展示
+  const fullId = taskFullId(task, projectCode)
+  const [copied, setCopied] = useState(false)
+  useEffect(() => { setCopied(false) }, [task.id])
+  useEffect(() => {
+    if (!copied) return undefined
+    const t = setTimeout(() => setCopied(false), 1500)
+    return () => clearTimeout(t)
+  }, [copied])
+
+  async function copyId(e) {
+    e.stopPropagation()
+    const ok = await copyText(fullId)
+    setCopied(ok)
+    Toast.show({ content: ok ? `已复制 ${fullId}` : '复制失败，请长按手动复制' })
+  }
+
   // 可作为父任务的候选: 同项目顶层任务, 排除自己与已有子任务的任务 (T-ST-01/13)
   const parentCandidates = (tasks || []).filter(
     (t) => t.id !== task.id && (t.children || []).length === 0,
@@ -82,23 +123,26 @@ export default function TaskDetail({ task, columns, members, tasks, taskKinds, o
     }
   }
 
-  /** 换列: 服务端按目标列绑定裁决状态 (T-BD-04/07) */
+  /** 换列: 服务端按目标列绑定裁决状态 (T-BD-04/07)
+   *  本地库的列 id 为 uuid 字符串, 而 ActionSheet 的 key 会被转成字符串 ——
+   *  这里始终按 String() 比对, 不要 Number(): 否则结果变 NaN, 落库列被改成 "NaN" 报「看板列不存在」 */
   function pickColumn() {
+    const current = String(task.columnId)
     ActionSheet.show({
       actions: (columns || []).map((c) => ({
-        text: c.name + (c.id === task.columnId ? ' ✓' : ''),
+        text: c.name + (String(c.id) === current ? ' ✓' : ''),
         key: String(c.id),
       })),
       cancelText: '取消',
       onAction: async (item) => {
-        const columnId = Number(item.key)
-        if (columnId === task.columnId) return
+        const columnId = String(item.key)
+        if (columnId === current) return
         try {
           const r = await taskApi.update(task.id, { columnId })
-          Toast.show({ content: `已移入 ${(columns || []).find((c) => c.id === columnId)?.name || '目标列'}` })
+          Toast.show({ content: `已移入 ${(columns || []).find((c) => String(c.id) === columnId)?.name || '目标列'}` })
           onSaved?.(r.item)
         } catch (e) {
-          Toast.show({ content: e.message })
+          Toast.show({ content: e.message || '换列失败' })
         }
       },
     })
@@ -161,6 +205,19 @@ export default function TaskDetail({ task, columns, members, tasks, taskKinds, o
       }}
     >
       <div className="sheet-title">{task.title}</div>
+      {fullId && (
+        <div className="sheet-idrow">
+          <span
+            className="task-id-chip"
+            role="button"
+            title="点击复制完整任务编号"
+            onClick={copyId}
+          >
+            <span className="tid">{fullId}</span>
+            <span className="tid-copy">{copied ? '已复制' : '复制'}</span>
+          </span>
+        </div>
+      )}
       <div className="sheet-sub">
         {currentCol?.name} · {STATUS_LABEL[task.status]}
       </div>
diff --git a/src/pages/task/date.js b/src/pages/task/date.js
index 19c5f60..fad7b9f 100644
--- a/src/pages/task/date.js
+++ b/src/pages/task/date.js
@@ -16,6 +16,23 @@ export const RETENTION_OPTIONS = ['never', 'today', '3d', 'week', 'month', 'fore
 export const STATUS_LABEL = { todo: '未开始', doing: '执行中', done: '完成' }
 export const STATUS_OPTIONS = ['todo', 'doing', 'done']
 
+// 任务编号 (T-TK-编号): 服务端分配 `Project.code` + 项目内自增 `Task.number`
+//   - 列表 / 看板: 只显示 `#序号` (短, 不占卡片宽度)
+//   - 详情页: 显示完整编号 `项目编号-序号`, 点按复制
+//   - 离线新建、上行定号前的任务 number 为空 -> 两处都不出编号 (不做假编号)
+/** 列表 / 看板的短编号: '#12'; 未定号返回 null */
+export function taskShortId(task) {
+  const n = task?.number
+  return n === null || n === undefined || n === '' ? null : `#${n}`
+}
+
+/** 完整任务编号: 'IB-12'; 未定号返回 null */
+export function taskFullId(task, code) {
+  const n = task?.number
+  if (n === null || n === undefined || n === '') return null
+  return code ? `${code}-${n}` : `#${n}`
+}
+
 const FMT = new Intl.DateTimeFormat('en-CA', {
   timeZone: TZ, year: 'numeric', month: '2-digit', day: '2-digit',
 })
diff --git a/src/styles/globals.css b/src/styles/globals.css
index e2a4f12..7adf449 100644
--- a/src/styles/globals.css
+++ b/src/styles/globals.css
@@ -1207,6 +1207,21 @@ body.me-safe-top .app-safe-top { height: 0; }
   font-size: 11.5px; color: #999; margin-bottom: 14px;
   overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
 }
+/* 详情页标题下的完整任务编号 (项目编号-序号): 点按复制 */
+.sheet-idrow { margin: -1px 0 6px; }
+.task-id-chip {
+  display: inline-flex; align-items: center; gap: 6px;
+  font-size: 11px; line-height: 1; font-weight: 600;
+  color: #5b6b7c; background: #eef2f6; border-radius: 999px; padding: 5px 9px;
+  cursor: pointer; -webkit-user-select: none; user-select: none;
+  font-variant-numeric: tabular-nums;
+}
+.task-id-chip:active { background: #e2e8ef; }
+.task-id-chip .tid { letter-spacing: .3px; }
+.task-id-chip .tid-copy {
+  color: var(--color-primary); font-weight: 500;
+  padding-left: 6px; border-left: 1px solid rgba(91,107,124,.22);
+}
 .field { margin-bottom: 13px; }
 .field label { display: block; font-size: 12px; color: var(--color-muted); margin-bottom: 6px; }
 .inp {