diff --git a/frontend/detail-defer.js b/frontend/detail-defer.js
new file mode 100644
index 0000000..943da0c
--- /dev/null
+++ b/frontend/detail-defer.js
@@ -0,0 +1,25 @@
+function createDetailDefer({
+  laterWork,
+  session,
+  close,
+  refresh,
+  focus,
+  announce,
+  formatTime = value => new Date(value).toLocaleString(),
+}) {
+  return {
+    defer(item, preset) {
+      if (!item) return false;
+      const until = laterWork.presetUntil(preset);
+      if (!laterWork.defer(item, until)) return false;
+      const inSession = session.active();
+      if (!inSession) close();
+      refresh();
+      announce('Deferred until ' + formatTime(until) + '. It stays unread and unchanged in Gitea.');
+      if (!inSession) focus();
+      return true;
+    },
+  };
+}
+
+if (typeof module !== 'undefined' && module.exports) module.exports = createDetailDefer;
diff --git a/frontend/index.html b/frontend/index.html
index e171104..74625ed 100644
--- a/frontend/index.html
+++ b/frontend/index.html
@@ -84,6 +84,11 @@ textarea { resize: vertical; min-height: 120px; }
 .my-work-card-title { display:block; margin:5px 0; font-weight:650; }
 .later-actions { display:grid; grid-template-columns:repeat(auto-fit,minmax(120px,1fr)); gap:8px; }
 .later-actions button { min-height:44px; width:100%; }
+.detail-defer { grid-column:1/-1; max-width:100%; }
+.detail-defer summary, .detail-defer button { min-height:44px; display:flex; align-items:center; justify-content:center; }
+.detail-defer summary { cursor:pointer; border:1px solid #60a5fa; border-radius:10px; font-weight:700; }
+.detail-defer-options { display:grid; grid-template-columns:repeat(auto-fit,minmax(120px,1fr)); gap:8px; margin-top:8px; }
+.review-sheet-actions { position:sticky; bottom:0; z-index:3; padding:10px 4px; padding-bottom:calc(10px + env(safe-area-inset-bottom)); background:rgba(11,21,38,.98); border-top:1px solid #2a496e; }
 .mark-update-read { min-height:44px; width:100%; }
 .read-update { min-height:44px; width:100%; display:flex; align-items:center; justify-content:center; }
 .load-more-notifications { min-height:44px; width:100%; margin-top:10px; }
@@ -514,6 +519,7 @@ textarea { resize: vertical; min-height: 120px; }
       <button id="release-issue" type="button">Release assignment</button>
       <button id="close-issue" type="button">Close issue</button>
       <a id="open-issue-gitea" href="#" target="_blank" rel="noopener noreferrer">Open in Gitea</a>
+      <details class="detail-defer"><summary>Defer</summary><div class="detail-defer-options"><button type="button" data-detail-defer-preset="today">Later today</button><button type="button" data-detail-defer-preset="tomorrow">Tomorrow</button><button type="button" data-detail-defer-cancel>Cancel</button></div></details>
     </div>
     <nav class="work-session-nav" aria-label="Work session" hidden>
       <span class="small" aria-live="polite" data-work-session-progress></span>
@@ -617,6 +623,7 @@ textarea { resize: vertical; min-height: 120px; }
       <button class="share-work-route" type="button">Share</button>
       <button id="mark-update-read-next" type="button">Mark read &amp; next</button>
       <a id="open-update-gitea" href="#" target="_blank" rel="noopener noreferrer">Open in Gitea</a>
+      <details class="detail-defer"><summary>Defer</summary><div class="detail-defer-options"><button type="button" data-detail-defer-preset="today">Later today</button><button type="button" data-detail-defer-preset="tomorrow">Tomorrow</button><button type="button" data-detail-defer-cancel>Cancel</button></div></details>
     </div>
     <nav class="work-session-nav" aria-label="Work session" hidden>
       <span class="small" aria-live="polite" data-work-session-progress></span>
@@ -656,6 +663,7 @@ textarea { resize: vertical; min-height: 120px; }
     <div class="pull-sheet-actions">
       <button class="share-work-route" type="button">Share</button>
       <a id="open-pull-gitea" href="#" target="_blank" rel="noopener noreferrer">Open in Gitea</a>
+      <details class="detail-defer"><summary>Defer</summary><div class="detail-defer-options"><button type="button" data-detail-defer-preset="today">Later today</button><button type="button" data-detail-defer-preset="tomorrow">Tomorrow</button><button type="button" data-detail-defer-cancel>Cancel</button></div></details>
     </div>
     <nav class="work-session-nav" aria-label="Work session" hidden>
       <span class="small" aria-live="polite" data-work-session-progress></span>
@@ -720,6 +728,7 @@ textarea { resize: vertical; min-height: 120px; }
     </section>
     <h2>Review history</h2>
     <div id="review-history" class="muted"></div>
+    <div class="review-sheet-actions"><details class="detail-defer"><summary>Defer</summary><div class="detail-defer-options"><button type="button" data-detail-defer-preset="today">Later today</button><button type="button" data-detail-defer-preset="tomorrow">Tomorrow</button><button type="button" data-detail-defer-cancel>Cancel</button></div></details></div>
     <nav class="work-session-nav" aria-label="Work session" hidden>
       <span class="small" aria-live="polite" data-work-session-progress></span>
       <button type="button" data-work-session-previous>Previous</button>
@@ -750,6 +759,7 @@ textarea { resize: vertical; min-height: 120px; }
 <script src="static/offline-work.js"></script>
 <script src="static/my-work.js"></script>
 <script src="static/later-work.js"></script>
+<script src="static/detail-defer.js"></script>
 <script src="static/pick-work.js"></script>
 <script src="static/conversation.js"></script>
 <script src="static/issue-sheet.js"></script>
@@ -1255,6 +1265,30 @@ textarea { resize: vertical; min-height: 120px; }
     },
   });
 
+  const detailDefer = createDetailDefer({
+    laterWork,
+    session: workSession,
+    close: () => workRoute.close(),
+    refresh: refreshMyWorkView,
+    focus: () => qs('[data-work-filter="' + selectedWorkFilter + '"]')?.focus(),
+    announce: message => { qs('#my-work-action-status').textContent = message; },
+    formatTime: fmt,
+  });
+  document.querySelectorAll('[data-detail-defer-preset]').forEach(button => {
+    button.addEventListener('click', () => {
+      const item = selectedUpdate || selectedReview || selectedIssue || selectedPull;
+      button.closest('.detail-defer').open = false;
+      detailDefer.defer(item, button.dataset.detailDeferPreset);
+    });
+  });
+  document.querySelectorAll('[data-detail-defer-cancel]').forEach(button => {
+    button.addEventListener('click', () => {
+      const chooser = button.closest('.detail-defer');
+      chooser.open = false;
+      chooser.querySelector('summary')?.focus();
+    });
+  });
+
   function renderContextSnapshot(data) {
     liveMode = true;
     hasContextSnapshot = true;
diff --git a/frontend/service-worker.js b/frontend/service-worker.js
index 703b0f9..fbd115d 100644
--- a/frontend/service-worker.js
+++ b/frontend/service-worker.js
@@ -1,6 +1,6 @@
 const BASE = new URL('./', self.location.href).pathname;
 importScripts(BASE + 'static/background-issue-sync.js');
-const CACHE = 'stackchain-dashboard-shell-v14';
+const CACHE = 'stackchain-dashboard-shell-v15';
 const OUTAGE_STATUSES = new Set([500, 502, 503, 504]);
 const SHELL = [
   BASE,
@@ -18,6 +18,7 @@ const SHELL = [
   BASE + 'static/offline-work.js',
   BASE + 'static/my-work.js',
   BASE + 'static/later-work.js',
+  BASE + 'static/detail-defer.js',
   BASE + 'static/pick-work.js',
   BASE + 'static/conversation.js',
   BASE + 'static/issue-sheet.js',
diff --git a/tests/test_my_work.py b/tests/test_my_work.py
index eb5d70a..6608f60 100644
--- a/tests/test_my_work.py
+++ b/tests/test_my_work.py
@@ -10,6 +10,7 @@ from src.views import dashboard
 
 MY_WORK = Path(__file__).parents[1] / "frontend" / "my-work.js"
 LATER_WORK = Path(__file__).parents[1] / "frontend" / "later-work.js"
+DETAIL_DEFER = Path(__file__).parents[1] / "frontend" / "detail-defer.js"
 REVIEW_SHEET = Path(__file__).parents[1] / "frontend" / "review-sheet.js"
 ISSUE_SHEET = Path(__file__).parents[1] / "frontend" / "issue-sheet.js"
 CREATE_ISSUE_SHEET = Path(__file__).parents[1] / "frontend" / "create-issue-sheet.js"
@@ -838,6 +839,65 @@ process.stdout.write(JSON.stringify({{
     }
 
 
+def test_detail_defer_closes_normal_triage_but_keeps_session_open_for_reconcile():
+    script = f"""
+const createDetailDefer = require({json.dumps(str(DETAIL_DEFER))});
+const calls = [];
+let sessionActive = false;
+const controller = createDetailDefer({{
+  laterWork: {{
+    presetUntil:preset => new Date(preset === 'today' ? '2026-08-08T16:00:00Z' : '2026-08-09T09:00:00Z'),
+    defer:(item, until) => {{ calls.push(['defer', item.title, until.toISOString()]); return true; }},
+  }},
+  session: {{ active:() => sessionActive }},
+  close:() => calls.push(['close']),
+  refresh:() => calls.push(['refresh']),
+  focus:() => calls.push(['focus']),
+  announce:message => calls.push(['announce', message]),
+  formatTime:value => value.toISOString(),
+}});
+const item = {{kind:'issue',repository:'stackchain/api',number:17,title:'Read first'}};
+const outside = controller.defer(item, 'today');
+sessionActive = true;
+const session = controller.defer(item, 'tomorrow');
+process.stdout.write(JSON.stringify({{outside,session,calls}}));
+"""
+
+    result = subprocess.run(
+        ["node", "-e", script], check=True, capture_output=True, text=True
+    )
+
+    assert json.loads(result.stdout) == {
+        "outside": True,
+        "session": True,
+        "calls": [
+            ["defer", "Read first", "2026-08-08T16:00:00.000Z"],
+            ["close"],
+            ["refresh"],
+            ["announce", "Deferred until 2026-08-08T16:00:00.000Z. It stays unread and unchanged in Gitea."],
+            ["focus"],
+            ["defer", "Read first", "2026-08-09T09:00:00.000Z"],
+            ["refresh"],
+            ["announce", "Deferred until 2026-08-09T09:00:00.000Z. It stays unread and unchanged in Gitea."],
+        ],
+    }
+
+
+@pytest.mark.anyio
+async def test_mobile_detail_sheets_offer_touch_safe_defer_without_a_gitea_mutation():
+    html = await dashboard()
+
+    assert '<script src="static/detail-defer.js"></script>' in html
+    assert html.count('class="detail-defer"') == 4
+    assert html.count('data-detail-defer-preset="today"') == 4
+    assert html.count('data-detail-defer-preset="tomorrow"') == 4
+    assert 'const detailDefer = createDetailDefer({' in html
+    assert 'selectedUpdate || selectedReview || selectedIssue || selectedPull' in html
+    assert "detailDefer.defer(item, button.dataset.detailDeferPreset)" in html
+    assert ".detail-defer summary, .detail-defer button { min-height:44px;" in html
+    assert "fetch(" not in DETAIL_DEFER.read_text()
+
+
 @pytest.mark.anyio
 async def test_mobile_my_work_wires_touch_safe_non_mutating_later_actions():
     html = await dashboard()
diff --git a/tests/test_service_worker.py b/tests/test_service_worker.py
index b4289dc..fd383a5 100644
--- a/tests/test_service_worker.py
+++ b/tests/test_service_worker.py
@@ -70,10 +70,10 @@ async function dispatchSync(tag) {{
     return json.loads(completed.stdout)
 
 
-def test_background_authored_sync_ships_in_a_new_shell_cache():
+def test_detail_defer_ships_in_a_new_shell_cache():
     source = WORKER.read_text()
 
-    assert "stackchain-dashboard-shell-v14" in source
+    assert "stackchain-dashboard-shell-v15" in source
 
 
 def test_background_sync_event_flushes_closed_app_issue_outbox_only_for_its_tag():
@@ -114,6 +114,7 @@ def test_install_precaches_complete_subpath_scoped_app_shell():
         "/dashboard/static/offline-work.js",
         "/dashboard/static/my-work.js",
         "/dashboard/static/later-work.js",
+        "/dashboard/static/detail-defer.js",
         "/dashboard/static/pick-work.js",
         "/dashboard/static/conversation.js",
         "/dashboard/static/issue-sheet.js",