diff --git a/screen_locker/_constants.py b/screen_locker/_constants.py
index f77f9b4..36f67fa 100644
--- a/screen_locker/_constants.py
+++ b/screen_locker/_constants.py
@@ -36,8 +36,8 @@ COMMITMENT_PROMPT_TIMEOUT_SECONDS = 15
 # window is exhausted the "Log Manual Workout" option disappears entirely.
 MANUAL_WORKOUT_BUDGET_PER_7_DAYS = 2
 MANUAL_WORKOUT_BUDGET_PER_30_DAYS = 10
-# Minimum start-to-end duration for a manual entry to be accepted.
-MANUAL_WORKOUT_MIN_DURATION_MINUTES = 20
+# Manual entries use the shared MIN_WORKOUT_DURATION_MINUTES bar below —
+# every workout type answers to the same minimum, whatever the sport.
 # Minimum chars for the "what was done" activity-details field.
 MANUAL_WORKOUT_DESCRIPTION_MIN_CHARS = 40
 # Minimum chars for each reflection field (what went well / to improve / feeling).
@@ -55,19 +55,37 @@ WORKOUT_APP_JSON_REMOTES = (
 )
 # Port the workout app's HTTP server listens on (no ADB/developer-options needed).
 WORKOUT_HTTP_PORT = 8765
-MIN_WORKOUT_DURATION_MINUTES = 60
+# The ONE duration bar every workout type answers to — weightlifting, manual
+# entries and runs alike. This is the ADVERTISED number: it is the only one
+# that may ever appear in a message the user reads.
+MIN_WORKOUT_DURATION_MINUTES = 40
+# ...and this is the leeway that is deliberately INVISIBLE. A session is
+# actually accepted at MIN_WORKOUT_DURATION_MINUTES - this, so 35 minutes
+# passes while every string still says 40. That gap is intentional (the user
+# asked for it explicitly): do NOT "fix" the inconsistency by advertising the
+# real cutoff, and never interpolate WORKOUT_DURATION_ACCEPT_MINUTES into an
+# f-string.
+WORKOUT_DURATION_LEEWAY_MINUTES = 5
+# Derived so the advertised bar and the accept bar cannot drift apart.
+# Comparisons use this; messages use MIN_WORKOUT_DURATION_MINUTES. Every
+# caller compares with `>=` — one operator across all workout types, so a
+# 35.0-minute session cannot pass one gate and fail another.
+WORKOUT_DURATION_ACCEPT_MINUTES = (
+    MIN_WORKOUT_DURATION_MINUTES - WORKOUT_DURATION_LEEWAY_MINUTES
+)
 RUNNERUP_PACKAGES = ("org.runnerup", "org.runnerup.free")
 RUNNERUP_DB_SDCARD_TMP = "/sdcard/.runnerup_tmp_verification.db"
 # A run qualifies on EITHER criterion — they are an OR, not an AND. A short
-# but long-lasting run counts, and so does a fast 5 km that takes under 40 min.
-# Do not reinstate an AND here: it would reject exactly the slow-run case this
-# pair exists to allow.
-MIN_RUN_DURATION_MINUTES = 40  # strict: "over 40 minutes"
+# but long-lasting run counts, and so does a fast 5 km that takes under the
+# duration bar. Do not reinstate an AND here: it would reject exactly the
+# slow-run case this pair exists to allow. The duration arm is the shared
+# MIN_WORKOUT_DURATION_MINUTES above; only the distance arm is run-specific.
 MIN_RUN_DISTANCE_KM = 3.5  # inclusive: "as low as 3.5 km"
 # GPS distance tracking undershoots on tight turns/tree cover/urban canyons;
 # a run within 5% of the minimum is accepted rather than rejected on
-# measurement noise. Duration comes from the device clock, not GPS, so it
-# gets no such leeway.
+# measurement noise. This is SEPARATE from WORKOUT_DURATION_LEEWAY_MINUTES:
+# that one is a deliberate concession to the user, this one corrects a
+# measurement error. Duration now gets a leeway too, but for the other reason.
 RUNNERUP_DISTANCE_TOLERANCE = 0.05
 RUNNERUP_ACCEPTED_SPORTS: frozenset[int] = frozenset({0, 3, 5})
 # 0=RUNNING, 3=ORIENTEERING, 5=TREADMILL
diff --git a/screen_locker/_manual_workout.py b/screen_locker/_manual_workout.py
index 7ba1ac6..2b89886 100644
--- a/screen_locker/_manual_workout.py
+++ b/screen_locker/_manual_workout.py
@@ -24,10 +24,11 @@ from screen_locker._constants import (
     MANUAL_WORKOUT_BUDGET_PER_7_DAYS,
     MANUAL_WORKOUT_BUDGET_PER_30_DAYS,
     MANUAL_WORKOUT_DESCRIPTION_MIN_CHARS,
-    MANUAL_WORKOUT_MIN_DURATION_MINUTES,
     MANUAL_WORKOUT_REFLECTION_MIN_CHARS,
     MANUAL_WORKOUT_RPE_MAX,
     MANUAL_WORKOUT_RPE_MIN,
+    MIN_WORKOUT_DURATION_MINUTES,
+    WORKOUT_DURATION_ACCEPT_MINUTES,
 )
 from screen_locker._log_io import load_workout_log
 
@@ -203,9 +204,11 @@ def validate_manual_workout(draft: ManualWorkoutDraft) -> str | None:
     duration = _duration_minutes(draft)
     if duration is None:
         return "Start/end time must be valid HH:MM, with end after start"
-    if duration < MANUAL_WORKOUT_MIN_DURATION_MINUTES:
+    # Accept bar carries the hidden leeway; the message advertises the round
+    # number only (see _constants.py).
+    if duration < WORKOUT_DURATION_ACCEPT_MINUTES:
         return (
-            f"Session must be at least {MANUAL_WORKOUT_MIN_DURATION_MINUTES} "
+            f"Session must be at least {MIN_WORKOUT_DURATION_MINUTES} "
             f"minutes (currently {duration:.0f})"
         )
 
diff --git a/screen_locker/_phone_verification.py b/screen_locker/_phone_verification.py
index 0558d8b..a690112 100644
--- a/screen_locker/_phone_verification.py
+++ b/screen_locker/_phone_verification.py
@@ -22,6 +22,7 @@ from screen_locker._constants import (
     ADB_TIMEOUT,
     MIN_WORKOUT_DURATION_MINUTES,
     WORKOUT_APP_JSON_REMOTES,
+    WORKOUT_DURATION_ACCEPT_MINUTES,
     WORKOUT_HTTP_PORT,
 )
 from screen_locker._log_mixin import write_signed_entry
@@ -187,7 +188,9 @@ class PhoneVerificationMixin:
         if not data.get("exercises"):
             return "no_exercises", "No exercises found in the workout JSON"
         duration_min = data.get("duration_seconds", 0) / 60.0
-        if duration_min < MIN_WORKOUT_DURATION_MINUTES:
+        # Accept bar carries the hidden leeway; the message advertises the
+        # round number only (see _constants.py).
+        if duration_min < WORKOUT_DURATION_ACCEPT_MINUTES:
             return (
                 "too_short",
                 f"Workout too short! {duration_min:.0f} min logged, "
diff --git a/screen_locker/_runnerup_verification.py b/screen_locker/_runnerup_verification.py
index fb3aa35..d38ba1a 100644
--- a/screen_locker/_runnerup_verification.py
+++ b/screen_locker/_runnerup_verification.py
@@ -17,10 +17,11 @@ import xml.etree.ElementTree as ET
 
 from screen_locker._constants import (
     MIN_RUN_DISTANCE_KM,
-    MIN_RUN_DURATION_MINUTES,
+    MIN_WORKOUT_DURATION_MINUTES,
     RUNNERUP_ACCEPTED_SPORTS,
     RUNNERUP_DISTANCE_TOLERANCE,
     RUNNERUP_EXPORT_DIRS,
+    WORKOUT_DURATION_ACCEPT_MINUTES,
 )
 from screen_locker._log_mixin import write_signed_entry
 from screen_locker._runnerup_db import RunnerUpDbMixin
@@ -248,16 +249,17 @@ class RunnerUpVerificationMixin(RunnerUpDbMixin):
         distance_km = data["distance_m"] / 1000
 
         # Either criterion qualifies the run on its own (see _constants.py).
-        # Distance gets the GPS tolerance; duration, from the device clock,
-        # does not.
+        # Distance gets the GPS tolerance (a measurement correction); duration
+        # gets the shared hidden leeway (a deliberate concession). Different
+        # reasons, so they stay separate constants.
         distance_ok = (
             distance_km * (1 + RUNNERUP_DISTANCE_TOLERANCE) >= MIN_RUN_DISTANCE_KM
         )
-        duration_ok = duration_min > MIN_RUN_DURATION_MINUTES
+        duration_ok = duration_min >= WORKOUT_DURATION_ACCEPT_MINUTES
         if not distance_ok and not duration_ok:
             msg = (
                 f"Run was {distance_km:.1f} km / {duration_min:.0f} min — need "
-                f"{MIN_RUN_DISTANCE_KM:g}+ km or {MIN_RUN_DURATION_MINUTES}+ min"
+                f"{MIN_RUN_DISTANCE_KM:g}+ km or {MIN_WORKOUT_DURATION_MINUTES}+ min"
             )
             return "too_short", msg
         if distance_ok and distance_km < MIN_RUN_DISTANCE_KM:
diff --git a/screen_locker/tests/fixtures/duration_threshold.json b/screen_locker/tests/fixtures/duration_threshold.json
new file mode 100644
index 0000000..f01f96d
--- /dev/null
+++ b/screen_locker/tests/fixtures/duration_threshold.json
@@ -0,0 +1,23 @@
+{
+  "_comment": [
+    "Shared literal fixture for the unified workout-duration gate.",
+    "Read by BOTH the Python locker (test_duration_threshold_fixture.py) and",
+    "the Flutter app (test/models/duration_threshold_fixture_test.dart).",
+    "Each language's own round-trip test cannot catch a drift between the two",
+    "sides -- only a shared literal like this one can. If you change the",
+    "threshold, change it here and watch both suites fail together.",
+    "",
+    "advertised_minutes is the ONLY number that may appear in a user-facing",
+    "message. accept_minutes is deliberately invisible: a 35-minute session",
+    "passes while every string still says 40. Do not advertise accept_minutes."
+  ],
+  "advertised_minutes": 40,
+  "leeway_minutes": 5,
+  "accept_minutes": 35,
+  "cases": [
+    { "duration_minutes": 34, "accepted": false },
+    { "duration_minutes": 35, "accepted": true },
+    { "duration_minutes": 40, "accepted": true },
+    { "duration_minutes": 60, "accepted": true }
+  ]
+}
diff --git a/screen_locker/tests/test_duration_threshold_fixture.py b/screen_locker/tests/test_duration_threshold_fixture.py
new file mode 100644
index 0000000..295ad66
--- /dev/null
+++ b/screen_locker/tests/test_duration_threshold_fixture.py
@@ -0,0 +1,87 @@
+"""Cross-language fixture test for the unified workout-duration gate.
+
+The Dart app mirrors these constants in ``lib/models/manual_workout.dart``.
+Each language's own round-trip test passes happily while the two sides
+disagree, so the only thing that catches a drift is a shared literal both
+read -- ``fixtures/duration_threshold.json``. The Dart twin of this file is
+``test/models/duration_threshold_fixture_test.dart``; they must stay in step.
+"""
+
+from __future__ import annotations
+
+import json
+from pathlib import Path
+
+import pytest
+
+from screen_locker._constants import (
+    MIN_WORKOUT_DURATION_MINUTES,
+    WORKOUT_DURATION_ACCEPT_MINUTES,
+    WORKOUT_DURATION_LEEWAY_MINUTES,
+)
+from screen_locker._manual_workout import ManualWorkoutDraft, validate_manual_workout
+
+FIXTURE = Path(__file__).parent / "fixtures" / "duration_threshold.json"
+
+
+def _fixture() -> dict[str, object]:
+    """Load the shared cross-language threshold fixture."""
+    return json.loads(FIXTURE.read_text(encoding="utf-8"))
+
+
+def _draft(duration_minutes: int) -> ManualWorkoutDraft:
+    """Build an otherwise-valid draft of exactly ``duration_minutes``."""
+    end_h, end_m = divmod(12 * 60 + duration_minutes, 60)
+    return ManualWorkoutDraft(
+        sport="other",
+        start_time="12:00",
+        end_time=f"{end_h:02d}:{end_m:02d}",
+        location_name="Home",
+        transport_method="From bed",
+        cost="0",
+        rpe=3,
+        went_well="Everything went smoothly today, no issues at all",
+        to_improve="Dumbbell bench press needs assistance exercises",
+        overall_feeling="Felt strong throughout the whole session today",
+        reservation_phone="none",
+        techniques_practiced="FBW",
+        warm_up_minutes="none",
+        pain_or_injury="none",
+        activity_type_other="Weightlifting",
+        activity_details="Dumbbell Lunge, Press, Row and Dumbbell Curl at home",
+        equipment="Dumbbells",
+    )
+
+
+def test_constants_match_shared_fixture() -> None:
+    """The Python constants equal the shared literal the Dart side also reads."""
+    data = _fixture()
+    assert data["advertised_minutes"] == MIN_WORKOUT_DURATION_MINUTES
+    assert data["leeway_minutes"] == WORKOUT_DURATION_LEEWAY_MINUTES
+    assert data["accept_minutes"] == WORKOUT_DURATION_ACCEPT_MINUTES
+
+
+def test_accept_bar_is_derived_not_hardcoded() -> None:
+    """The two bars cannot drift: the accept bar is advertised minus leeway."""
+    assert (
+        WORKOUT_DURATION_ACCEPT_MINUTES
+        == MIN_WORKOUT_DURATION_MINUTES - WORKOUT_DURATION_LEEWAY_MINUTES
+    )
+
+
+@pytest.mark.parametrize("case", _fixture()["cases"])
+def test_boundary_cases_from_fixture(case: dict[str, object]) -> None:
+    """Every shared boundary case decides the same way on the Python side."""
+    error = validate_manual_workout(_draft(int(case["duration_minutes"])))
+    assert (error is None) is case["accepted"], (
+        f"{case['duration_minutes']} min should be "
+        f"{'accepted' if case['accepted'] else 'rejected'}, got {error!r}"
+    )
+
+
+def test_rejection_message_advertises_40_never_the_real_cutoff() -> None:
+    """The hidden accept bar must never reach the user's eyes."""
+    error = validate_manual_workout(_draft(10))
+    assert error is not None
+    assert str(MIN_WORKOUT_DURATION_MINUTES) in error
+    assert str(WORKOUT_DURATION_ACCEPT_MINUTES) not in error
diff --git a/screen_locker/tests/test_manual_workout.py b/screen_locker/tests/test_manual_workout.py
index 95955df..b453f82 100644
--- a/screen_locker/tests/test_manual_workout.py
+++ b/screen_locker/tests/test_manual_workout.py
@@ -14,8 +14,8 @@ from screen_locker._constants import (
     MANUAL_WORKOUT_BUDGET_PER_7_DAYS,
     MANUAL_WORKOUT_BUDGET_PER_30_DAYS,
     MANUAL_WORKOUT_DESCRIPTION_MIN_CHARS,
-    MANUAL_WORKOUT_MIN_DURATION_MINUTES,
     MANUAL_WORKOUT_REFLECTION_MIN_CHARS,
+    WORKOUT_DURATION_ACCEPT_MINUTES,
 )
 from screen_locker._manual_workout import (
     SPORT_OTHER,
@@ -239,7 +239,7 @@ class TestValidateManualWorkout:
 
     def test_rejects_too_short_duration(self) -> None:
         draft = _tt_draft(start_time="12:00", end_time="12:05")
-        assert MANUAL_WORKOUT_MIN_DURATION_MINUTES > 5
+        assert WORKOUT_DURATION_ACCEPT_MINUTES > 5
         assert validate_manual_workout(draft) is not None
 
     @pytest.mark.parametrize("rpe", [0, 11, -1])
diff --git a/screen_locker/tests/test_phone_verification_part4.py b/screen_locker/tests/test_phone_verification_part4.py
index 2d498ec..21a2b02 100644
--- a/screen_locker/tests/test_phone_verification_part4.py
+++ b/screen_locker/tests/test_phone_verification_part4.py
@@ -12,7 +12,10 @@ import time
 from typing import TYPE_CHECKING
 from unittest.mock import MagicMock, patch
 
-from screen_locker._constants import MIN_WORKOUT_DURATION_MINUTES
+from screen_locker._constants import (
+    MIN_WORKOUT_DURATION_MINUTES,
+    WORKOUT_DURATION_ACCEPT_MINUTES,
+)
 from screen_locker.tests.conftest import create_locker
 
 if TYPE_CHECKING:
@@ -59,12 +62,16 @@ class TestValidateJsonData:
         self, mock_tk: MagicMock, mock_sys_exit: MagicMock, tmp_path: Path
     ) -> None:
         locker = create_locker(mock_tk, tmp_path)
-        short_seconds = int((MIN_WORKOUT_DURATION_MINUTES - 10) * 60)
+        # Derive from the ACCEPT bar, not the advertised one: a duration
+        # merely under 40 may still clear the hidden leeway and verify.
+        short_seconds = int((WORKOUT_DURATION_ACCEPT_MINUTES - 5) * 60)
         status, message = locker._validate_json_data(
             {"date": _today(), "exercises": ["x"], "duration_seconds": short_seconds}
         )
         assert status == "too_short"
+        # ...but the message still advertises 40, never the real cutoff.
         assert f"{MIN_WORKOUT_DURATION_MINUTES}" in message
+        assert f"{WORKOUT_DURATION_ACCEPT_MINUTES}" not in message
 
     def test_verified_all_succeeded(
         self, mock_tk: MagicMock, mock_sys_exit: MagicMock, tmp_path: Path
diff --git a/screen_locker/tests/test_runnerup_verification_part2.py b/screen_locker/tests/test_runnerup_verification_part2.py
index 57e23f3..ab532b0 100644
--- a/screen_locker/tests/test_runnerup_verification_part2.py
+++ b/screen_locker/tests/test_runnerup_verification_part2.py
@@ -5,6 +5,10 @@ from __future__ import annotations
 from typing import TYPE_CHECKING
 from unittest.mock import MagicMock
 
+from screen_locker._constants import (
+    MIN_WORKOUT_DURATION_MINUTES,
+    WORKOUT_DURATION_ACCEPT_MINUTES,
+)
 from screen_locker.tests.conftest import create_locker
 
 if TYPE_CHECKING:
@@ -194,22 +198,40 @@ class TestValidateRunnerupDataOrCriteria:
         )
         assert status == "verified"
 
-    def test_duration_boundary_is_strict(
+    def test_duration_boundary_uses_the_hidden_leeway(
         self,
         mock_tk: MagicMock,
         mock_sys_exit: MagicMock,
         tmp_path: Path,
     ) -> None:
-        """Exactly 40 min does not qualify, but 40.1 min does ("over 40")."""
+        """Runs answer to the shared accept bar (35), not the advertised 40.
+
+        The distance stays at 1 km throughout so the OR distance arm cannot
+        rescue the run — this pins the duration arm alone.
+        """
         locker = create_locker(mock_tk, tmp_path)
-        at_boundary, _ = locker._validate_runnerup_data(
-            {"sport": 0, "duration_seconds": 2400, "distance_m": 1000}
+        just_under, _ = locker._validate_runnerup_data(
+            {"sport": 0, "duration_seconds": 2094, "distance_m": 1000}
         )
-        assert at_boundary == "too_short"
-        just_over, _ = locker._validate_runnerup_data(
-            {"sport": 0, "duration_seconds": 2406, "distance_m": 1000}
+        assert just_under == "too_short"
+        at_accept_bar, _ = locker._validate_runnerup_data(
+            {"sport": 0, "duration_seconds": 2100, "distance_m": 1000}
         )
-        assert just_over == "verified"
+        assert at_accept_bar == "verified"
+
+    def test_too_short_message_advertises_40_not_the_real_cutoff(
+        self,
+        mock_tk: MagicMock,
+        mock_sys_exit: MagicMock,
+        tmp_path: Path,
+    ) -> None:
+        """The hidden accept bar must never reach the user's eyes."""
+        locker = create_locker(mock_tk, tmp_path)
+        _, message = locker._validate_runnerup_data(
+            {"sport": 0, "duration_seconds": 600, "distance_m": 1000}
+        )
+        assert str(MIN_WORKOUT_DURATION_MINUTES) in message
+        assert str(WORKOUT_DURATION_ACCEPT_MINUTES) not in message
 
     def test_real_2026_08_14_run_is_verified(
         self,
diff --git a/stronglift_replacement/workout_app/lib/models/manual_workout.dart b/stronglift_replacement/workout_app/lib/models/manual_workout.dart
index c845ec4..c632fc9 100644
--- a/stronglift_replacement/workout_app/lib/models/manual_workout.dart
+++ b/stronglift_replacement/workout_app/lib/models/manual_workout.dart
@@ -27,8 +27,24 @@ const int kManualWorkoutBudgetPer7Days = 2;
 /// Max manual workouts allowed in any rolling 30-day window.
 const int kManualWorkoutBudgetPer30Days = 10;
 
-/// Minimum session length, in minutes, for a manual workout to count.
-const int kManualWorkoutMinDurationMinutes = 20;
+/// The ONE duration bar every workout type answers to, in minutes. This is
+/// the ADVERTISED number — the only one that may appear in a message the user
+/// reads. Mirrors `MIN_WORKOUT_DURATION_MINUTES` in the locker's
+/// `_constants.py`; the two must move together.
+const int kMinWorkoutDurationMinutes = 40;
+
+/// The leeway that is deliberately INVISIBLE. A session is accepted at
+/// [kMinWorkoutDurationMinutes] minus this, so 35 minutes passes while every
+/// string still says 40. That gap is intentional: do NOT "fix" it by
+/// advertising the real cutoff, and never interpolate
+/// [kWorkoutDurationAcceptMinutes] into a user-facing string.
+const int kWorkoutDurationLeewayMinutes = 5;
+
+/// Derived so the advertised and accept bars cannot drift apart. Comparisons
+/// use this; messages use [kMinWorkoutDurationMinutes]. Compare with `>=`,
+/// matching the locker, so 35.0 cannot pass one side and fail the other.
+const int kWorkoutDurationAcceptMinutes =
+    kMinWorkoutDurationMinutes - kWorkoutDurationLeewayMinutes;
 
 /// Minimum characters for the "other sport" activity description.
 const int kManualWorkoutDescriptionMinChars = 40;
@@ -204,8 +220,10 @@ String? validateManualWorkout(ManualWorkoutDraft draft) {
   if (duration == null) {
     return 'Start/end time must be valid HH:MM, with end after start';
   }
-  if (duration < kManualWorkoutMinDurationMinutes) {
-    return 'Session must be at least $kManualWorkoutMinDurationMinutes '
+  // Accept bar carries the hidden leeway; the message advertises the round
+  // number only.
+  if (duration < kWorkoutDurationAcceptMinutes) {
+    return 'Session must be at least $kMinWorkoutDurationMinutes '
         'minutes (currently ${duration.toStringAsFixed(0)})';
   }
 
diff --git a/stronglift_replacement/workout_app/lib/screens/home_screen.dart b/stronglift_replacement/workout_app/lib/screens/home_screen.dart
index cbaf511..e1d504b 100644
--- a/stronglift_replacement/workout_app/lib/screens/home_screen.dart
+++ b/stronglift_replacement/workout_app/lib/screens/home_screen.dart
@@ -9,12 +9,34 @@ import 'package:workout_app/screens/manual_workout_screen.dart';
 import 'package:workout_app/screens/settings_screen.dart';
 import 'package:workout_app/screens/workout_screen.dart';
 import 'package:workout_app/services/storage_service.dart';
+import 'package:workout_app/services/sync_status.dart';
+import 'package:workout_app/services/workout_sync_service.dart';
 import 'package:workout_app/ui/theme.dart';
+import 'package:workout_app/widgets/sync_status_card.dart';
 
 /// Home screen: auto-resumes active sessions and shows done-today status.
 class HomeScreen extends StatefulWidget {
   /// Creates a [HomeScreen].
-  const HomeScreen({super.key});
+  ///
+  /// [syncService], [clock] and [configuredProbe] are injection seams for
+  /// tests: the real sync service reaches the keystore and the network, and
+  /// "synced 3h ago" is only assertable against a fixed clock.
+  const HomeScreen({
+    super.key,
+    this.syncService,
+    this.clock,
+    this.configuredProbe,
+  });
+
+  /// Sync service to use; defaults to a real [WorkoutSyncService].
+  final WorkoutSyncService? syncService;
+
+  /// Source of "now"; defaults to [DateTime.now].
+  final DateTime Function()? clock;
+
+  /// Whether this device has sync credentials. Defaults to asking the
+  /// service itself.
+  final Future<bool> Function()? configuredProbe;
 
   @override
   State<HomeScreen> createState() => _HomeScreenState();
@@ -27,6 +49,11 @@ class _HomeScreenState extends State<HomeScreen> {
   bool _doneToday = false;
   Map<String, dynamic>? _savedSession;
 
+  /// Null until the first sync tick resolves, which keeps the card off the
+  /// screen rather than flashing a wrong state on launch.
+  SyncStatus? _syncStatus;
+  bool _syncing = false;
+
   /// True after the first load auto-navigated to an in-progress workout,
   /// so returning from workout does not auto-navigate again.
   bool _hasAutoResumed = false;
@@ -59,6 +86,11 @@ class _HomeScreenState extends State<HomeScreen> {
         _loading = false;
       });
 
+      // Sync in the background on every open. Deliberately not awaited: a
+      // slow or dead network must not hold up the workout screen, it just
+      // changes what the card says when it lands.
+      unawaited(_refreshSyncStatus());
+
       // Auto-resume active session on first load (app launch).
       if (saved != null && !_hasAutoResumed) {
         _hasAutoResumed = true;
@@ -69,6 +101,62 @@ class _HomeScreenState extends State<HomeScreen> {
     }
   }
 
+  /// Opens settings so the user can connect sync, then re-checks on return.
+  Future<void> _openSyncSettings() async {
+    await Navigator.of(context).push(
+      MaterialPageRoute<void>(builder: (_) => const SettingsScreen()),
+    );
+    unawaited(_load());
+  }
+
+  /// Runs a sync tick and folds the outcome into the status card.
+  ///
+  /// Never throws: [WorkoutSyncService.syncNow] reports failures as a
+  /// [PushResult] rather than an exception, and the card is where that
+  /// reason finally becomes visible to the user.
+  Future<void> _refreshSyncStatus() async {
+    if (_syncing) return; // a tick is already in flight
+    _syncing = true;
+    final storage = StorageService.instance;
+    final sync = widget.syncService ?? WorkoutSyncService();
+    final now = (widget.clock ?? DateTime.now)();
+    try {
+      final configured =
+          await (widget.configuredProbe ?? sync.isConfigured)();
+      final storedAt = await storage.getLastSyncedAt();
+
+      // Show what the PERSISTED state says before the tick resolves. Without
+      // this pass the card can never say "out of date": by the time a tick
+      // has finished it has either stamped the time (so the age is zero) or
+      // failed (so the card is "Sync failed"), and a phone that has not
+      // synced for days would look healthy for the whole tick. This is also
+      // the honest reading while the network is still being waited on.
+      if (mounted) {
+        setState(() {
+          _syncStatus = computeSyncStatus(
+            configured: configured,
+            now: now,
+            lastSyncedAt: storedAt,
+          );
+        });
+      }
+
+      final result = configured ? await sync.syncNow() : null;
+      if (result != null && result.pushed) {
+        await storage.markSyncedNow(now);
+      }
+      final status = computeSyncStatus(
+        configured: configured,
+        now: now,
+        lastResult: result,
+        lastSyncedAt: await storage.getLastSyncedAt(),
+      );
+      if (mounted) setState(() => _syncStatus = status);
+    } finally {
+      _syncing = false;
+    }
+  }
+
   Future<void> _openWorkout({bool resume = false}) async {
     final storage = StorageService.instance;
     Map<String, dynamic>? savedState;
@@ -141,6 +229,17 @@ class _HomeScreenState extends State<HomeScreen> {
               child: Column(
                 crossAxisAlignment: CrossAxisAlignment.stretch,
                 children: [
+                  // Above the workout card on purpose: a disconnected phone
+                  // has to say so BEFORE the workout, not after it failed to
+                  // count.
+                  if (_syncStatus case final status?) ...[
+                    SyncStatusCard(
+                      status: status,
+                      onRetry: () => unawaited(_refreshSyncStatus()),
+                      onSetUp: _openSyncSettings,
+                    ),
+                    const SizedBox(height: 20),
+                  ],
                   _WorkoutCard(
                     type: _nextType,
                     exercises: _exercises,
diff --git a/stronglift_replacement/workout_app/lib/services/storage_service.dart b/stronglift_replacement/workout_app/lib/services/storage_service.dart
index a182471..b7b1523 100644
--- a/stronglift_replacement/workout_app/lib/services/storage_service.dart
+++ b/stronglift_replacement/workout_app/lib/services/storage_service.dart
@@ -704,6 +704,35 @@ class StorageService {
 
   static const _progressionSyncedKey = 'progression_synced_at';
 
+  /// When a workout sync last SUCCEEDED, or null if one never has.
+  ///
+  /// Drives the home screen's "Out of date" card. Nothing persisted a
+  /// last-sync time before — which is why the app could sit disconnected for
+  /// days with nothing on screen saying so.
+  Future<DateTime?> getLastSyncedAt() async {
+    final raw = await _getSetting(_lastSyncedAtKey);
+    if (raw == null) return null;
+    final parsed = DateTime.tryParse(raw);
+    if (parsed == null) {
+      // Never silently treat a corrupt timestamp as "never synced": that
+      // would show the nag card forever with no clue why.
+      debugPrint(
+        'WorkoutApp: last_synced_at is not a valid timestamp ($raw) — '
+        'treating this device as never synced until the next success.',
+      );
+      return null;
+    }
+    return parsed;
+  }
+
+  /// Records that a sync just succeeded.
+  Future<void> markSyncedNow([DateTime? at]) => _setSetting(
+    _lastSyncedAtKey,
+    (at ?? DateTime.now()).toIso8601String(),
+  );
+
+  static const _lastSyncedAtKey = 'last_synced_at';
+
   /// Restores from backup if the local DB is empty (fresh install).
   ///
   /// "Empty" means no workout history and no [last_workout_type] setting.
diff --git a/stronglift_replacement/workout_app/lib/services/sync_status.dart b/stronglift_replacement/workout_app/lib/services/sync_status.dart
new file mode 100644
index 0000000..582d6b2
--- /dev/null
+++ b/stronglift_replacement/workout_app/lib/services/sync_status.dart
@@ -0,0 +1,95 @@
+/// The four states the home screen's sync card can show, and the pure
+/// function that decides between them.
+///
+/// This exists because a workout was once logged into a void: the app was not
+/// connected to Firebase, said nothing about it, and the session did not
+/// count. Silence was the bug. The card is the fix, and keeping the decision
+/// in a pure function means it can be tested without pumping a widget.
+library;
+
+import 'package:flutter/foundation.dart';
+import 'package:workout_app/services/workout_sync_service.dart';
+
+/// How long a successful sync stays "fresh" before the card nags.
+///
+/// The app is opened before each workout, so anything older than a few hours
+/// means the last open did not manage to sync.
+const Duration kSyncStaleAfter = Duration(hours: 6);
+
+/// Which of the four card states applies. Order matters -- see
+/// [computeSyncStatus].
+enum SyncState {
+  /// No credentials at all: this device has never been set up.
+  notConnected,
+
+  /// Credentials exist but the last attempt errored.
+  failed,
+
+  /// Last successful sync is older than [kSyncStaleAfter] (or never happened).
+  outOfDate,
+
+  /// Synced within the freshness window.
+  synced,
+}
+
+/// A resolved sync state plus the detail the card needs to render.
+@immutable
+class SyncStatus {
+  /// Creates a status.
+  const SyncStatus({required this.state, this.reason, this.age});
+
+  /// Which card to show.
+  final SyncState state;
+
+  /// For [SyncState.failed], the human-readable reason from [PushResult].
+  final String? reason;
+
+  /// For [SyncState.outOfDate] and [SyncState.synced], how long ago the last
+  /// successful sync was. Null when there has never been one.
+  final Duration? age;
+
+  @override
+  bool operator ==(Object other) =>
+      other is SyncStatus &&
+      other.state == state &&
+      other.reason == reason &&
+      other.age == age;
+
+  @override
+  int get hashCode => Object.hash(state, reason, age);
+
+  @override
+  String toString() => 'SyncStatus($state, reason: $reason, age: $age)';
+}
+
+/// Decides which card to show, first match wins.
+///
+/// The ordering is the point. On a fresh install there are no credentials
+/// *and* no timestamp, and "Not connected" is the useful thing to say --
+/// "Out of date" would send the user looking for a sync that never existed.
+///
+/// - [configured]: does this device have any sync credentials?
+/// - [lastResult]: the outcome of the most recent attempt this session.
+/// - [lastSyncedAt]: when a sync last succeeded, ever (persisted).
+/// - [now]: injected so "3h ago" is testable.
+SyncStatus computeSyncStatus({
+  required bool configured,
+  required DateTime now,
+  PushResult? lastResult,
+  DateTime? lastSyncedAt,
+}) {
+  if (!configured) {
+    return const SyncStatus(state: SyncState.notConnected);
+  }
+  if (lastResult != null && !lastResult.pushed) {
+    return SyncStatus(state: SyncState.failed, reason: lastResult.reason);
+  }
+  if (lastSyncedAt == null) {
+    return const SyncStatus(state: SyncState.outOfDate);
+  }
+  final age = now.difference(lastSyncedAt);
+  if (age >= kSyncStaleAfter) {
+    return SyncStatus(state: SyncState.outOfDate, age: age);
+  }
+  return SyncStatus(state: SyncState.synced, age: age);
+}
diff --git a/stronglift_replacement/workout_app/lib/services/workout_sync_service.dart b/stronglift_replacement/workout_app/lib/services/workout_sync_service.dart
index 2984854..3d5ff43 100644
--- a/stronglift_replacement/workout_app/lib/services/workout_sync_service.dart
+++ b/stronglift_replacement/workout_app/lib/services/workout_sync_service.dart
@@ -174,6 +174,79 @@ class WorkoutSyncService {
     }
   }
 
+  /// Whether this device has ANY sync credentials -- a GitHub token or a
+  /// Firebase account.
+  ///
+  /// Mirrors the gate every push already applies internally, exposed so the
+  /// home screen can tell "not set up" (the user must act) apart from "set
+  /// up but broken" (retrying might help) without duplicating the rule.
+  Future<bool> isConfigured() async {
+    final settings = await SyncSettings.load();
+    return settings.isConfigured || await _hasFirebaseAccount();
+  }
+
+  /// Runs a sync tick with no new record, purely to find out whether sync
+  /// works right now.
+  ///
+  /// [push] and [pushManual] both need something to push, and
+  /// [readMergedWorkoutPayloads] returns `const []` on failure -- it
+  /// swallows the reason, so neither can answer "is this device actually
+  /// talking to Firebase?". The home screen's status card needs exactly that
+  /// answer, with a reason a human can act on, which is why this exists.
+  ///
+  /// Same never-throw, always-report contract as [push].
+  Future<PushResult> syncNow() async {
+    final settings = await SyncSettings.load();
+    if (!settings.isConfigured && !await _hasFirebaseAccount()) {
+      const reason = 'sync not configured (no Firebase account, no token)';
+      log('WorkoutSyncService.syncNow skipped: $reason', level: 900);
+      return const PushResult(pushed: false, reason: reason);
+    }
+
+    final github = GitHubClient(
+      owner: owner,
+      repo: repo,
+      token: settings.token,
+      httpClient: _httpClient,
+    );
+    final firebase = await _openFirebase();
+    final client = firebase == null
+        ? github
+        : MirrorStore(primary: firebase, mirror: github);
+    try {
+      final path = '$_pathPrefix/$currentSyncDeviceId/$_logFilename';
+      final existingText = await client.getFileText(path);
+      final existingLog = existingText == null
+          ? <String, Record>{}
+          : _decode(existingText);
+      await syncLog(
+        client: client,
+        deviceId: currentSyncDeviceId,
+        legacyDeviceId: legacySyncDeviceId,
+        pathPrefix: _pathPrefix,
+        // No new record: whatever this device already has, unchanged. The
+        // point is the round trip, not the payload.
+        localLog: existingLog,
+        encode: _encode,
+        decode: _decode,
+        stateStore: await _openStateStore(),
+      );
+      return const PushResult(pushed: true, reason: 'synced');
+    } on Object catch (error, stackTrace) {
+      final reason = 'sync failed: $error';
+      log(
+        'WorkoutSyncService.syncNow failed',
+        level: 1000,
+        error: error,
+        stackTrace: stackTrace,
+      );
+      return PushResult(pushed: false, reason: reason);
+    } finally {
+      github.close();
+      firebase?.close();
+    }
+  }
+
   /// Pushes a pre-built manual-workout [record] to this device's log.
   ///
   /// Same never-throw, always-report contract as [push].
diff --git a/stronglift_replacement/workout_app/lib/widgets/sync_status_card.dart b/stronglift_replacement/workout_app/lib/widgets/sync_status_card.dart
new file mode 100644
index 0000000..ab47144
--- /dev/null
+++ b/stronglift_replacement/workout_app/lib/widgets/sync_status_card.dart
@@ -0,0 +1,135 @@
+/// The home screen's sync-status card.
+///
+/// Sits above the workout card so a disconnected phone says so *before* the
+/// workout, not after. A workout was once logged into a void because the app
+/// stayed silent about being disconnected; the three unhealthy states here
+/// all offer the fix rather than just reporting the problem.
+library;
+
+import 'package:flutter/material.dart';
+import 'package:workout_app/services/sync_status.dart';
+import 'package:workout_app/ui/theme.dart';
+
+/// Renders a [SyncStatus] as a card, with an action for the unhealthy states.
+class SyncStatusCard extends StatelessWidget {
+  /// Creates the card.
+  const SyncStatusCard({
+    required this.status,
+    required this.onRetry,
+    required this.onSetUp,
+    super.key,
+  });
+
+  /// What to show.
+  final SyncStatus status;
+
+  /// Runs another sync tick ([SyncState.failed] / [SyncState.outOfDate]).
+  final VoidCallback onRetry;
+
+  /// Opens sync settings ([SyncState.notConnected]).
+  final VoidCallback onSetUp;
+
+  /// Renders a duration the way a human would say it.
+  static String describeAge(Duration age) {
+    if (age.inMinutes < 1) return 'just now';
+    if (age.inMinutes < 60) return '${age.inMinutes}m ago';
+    if (age.inHours < 24) return '${age.inHours}h ago';
+    return '${age.inDays}d ago';
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final colorScheme = Theme.of(context).colorScheme;
+    final statusColors = Theme.of(context).extension<AppStatusColors>()!;
+
+    // The healthy state is a compact one-liner on purpose: a full card that
+    // is always there becomes wallpaper, and then the unhealthy ones stop
+    // being noticed too.
+    if (status.state == SyncState.synced) {
+      final age = status.age;
+      return Row(
+        mainAxisAlignment: MainAxisAlignment.center,
+        children: [
+          Icon(Icons.cloud_done, size: 16, color: statusColors.success),
+          const SizedBox(width: 8),
+          Text(
+            age == null ? 'Synced' : 'Synced ${describeAge(age)}',
+            style: Theme.of(context).textTheme.bodySmall?.copyWith(
+              color: statusColors.success,
+            ),
+          ),
+        ],
+      );
+    }
+
+    // SyncState.synced returned above, so only the three unhealthy states
+    // reach here. `notConnected` is the default arm rather than a listed one
+    // so the switch has no unreachable branch to leave uncovered.
+    final (icon, accent, title, body, actionLabel, action) = switch (status
+        .state) {
+      SyncState.failed => (
+        Icons.sync_problem,
+        colorScheme.error,
+        'Sync failed',
+        status.reason ?? 'The last sync attempt did not go through.',
+        'Retry',
+        onRetry,
+      ),
+      SyncState.outOfDate => (
+        Icons.cloud_queue,
+        statusColors.warning,
+        'Sync out of date',
+        status.age == null
+            ? 'This device has never synced successfully.'
+            : 'Last synced ${describeAge(status.age!)}.',
+        'Retry',
+        onRetry,
+      ),
+      // notConnected (and, unreachably, synced) land here.
+      _ => (
+        Icons.cloud_off,
+        colorScheme.error,
+        'Not connected to sync',
+        'This workout will NOT count until sync is set up.',
+        'Set up sync',
+        onSetUp,
+      ),
+    };
+
+    return Card(
+      color: colorScheme.surfaceContainerHigh,
+      shape: RoundedRectangleBorder(
+        borderRadius: BorderRadius.circular(12),
+        side: BorderSide(color: accent),
+      ),
+      child: Padding(
+        padding: const EdgeInsets.all(16),
+        child: Row(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Icon(icon, color: accent),
+            const SizedBox(width: 12),
+            Expanded(
+              child: Column(
+                crossAxisAlignment: CrossAxisAlignment.start,
+                children: [
+                  Text(
+                    title,
+                    style: Theme.of(context).textTheme.titleSmall?.copyWith(
+                      color: accent,
+                      fontWeight: FontWeight.bold,
+                    ),
+                  ),
+                  const SizedBox(height: 4),
+                  Text(body, style: Theme.of(context).textTheme.bodySmall),
+                ],
+              ),
+            ),
+            const SizedBox(width: 8),
+            TextButton(onPressed: action, child: Text(actionLabel)),
+          ],
+        ),
+      ),
+    );
+  }
+}
diff --git a/stronglift_replacement/workout_app/test/models/duration_threshold_fixture_test.dart b/stronglift_replacement/workout_app/test/models/duration_threshold_fixture_test.dart
new file mode 100644
index 0000000..c96dc6a
--- /dev/null
+++ b/stronglift_replacement/workout_app/test/models/duration_threshold_fixture_test.dart
@@ -0,0 +1,98 @@
+@TestOn('vm')
+library;
+
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:workout_app/models/manual_workout.dart';
+
+/// Cross-language fixture test for the unified workout-duration gate.
+///
+/// The locker mirrors these constants in `screen_locker/_constants.py`. Each
+/// language's own round-trip test passes happily while the two sides
+/// disagree, so the only thing that catches a drift is a shared literal both
+/// read. The Python twin of this file is
+/// `screen_locker/tests/test_duration_threshold_fixture.py`.
+///
+/// The fixture lives in the locker's test tree because that is the side that
+/// owns the gate; this app reads it up four directories.
+final File _fixtureFile = File(
+  '../../screen_locker/tests/fixtures/duration_threshold.json',
+);
+
+Map<String, dynamic> _fixture() =>
+    jsonDecode(_fixtureFile.readAsStringSync()) as Map<String, dynamic>;
+
+/// Builds an otherwise-valid "other sport" draft of exactly [durationMinutes].
+ManualWorkoutDraft _draft(int durationMinutes) {
+  final totalMinutes = 12 * 60 + durationMinutes;
+  final endH = (totalMinutes ~/ 60).toString().padLeft(2, '0');
+  final endM = (totalMinutes % 60).toString().padLeft(2, '0');
+  return ManualWorkoutDraft(
+    sport: kSportOther,
+    startTime: '12:00',
+    endTime: '$endH:$endM',
+    locationName: 'Home',
+    transportMethod: 'From bed',
+    cost: '0',
+    rpe: 3,
+    wentWell: 'Everything went smoothly today, no issues at all',
+    toImprove: 'Dumbbell bench press needs assistance exercises',
+    overallFeeling: 'Felt strong throughout the whole session today',
+    reservationPhone: 'none',
+    techniquesPracticed: 'FBW',
+    warmUpMinutes: 'none',
+    painOrInjury: 'none',
+    activityTypeOther: 'Weightlifting',
+    activityDetails: 'Dumbbell Lunge, Press, Row and Dumbbell Curl at home',
+    equipment: 'Dumbbells',
+  );
+}
+
+void main() {
+  test('the shared fixture exists where both languages can read it', () {
+    expect(
+      _fixtureFile.existsSync(),
+      isTrue,
+      reason: 'Shared threshold fixture missing at ${_fixtureFile.path}',
+    );
+  });
+
+  test('Dart constants match the shared literal the locker also reads', () {
+    final data = _fixture();
+    expect(kMinWorkoutDurationMinutes, data['advertised_minutes']);
+    expect(kWorkoutDurationLeewayMinutes, data['leeway_minutes']);
+    expect(kWorkoutDurationAcceptMinutes, data['accept_minutes']);
+  });
+
+  test('the accept bar is derived, not hardcoded', () {
+    expect(
+      kWorkoutDurationAcceptMinutes,
+      kMinWorkoutDurationMinutes - kWorkoutDurationLeewayMinutes,
+    );
+  });
+
+  test('every shared boundary case decides the same way here', () {
+    for (final dynamic entry in _fixture()['cases'] as List<dynamic>) {
+      final c = entry as Map<String, dynamic>;
+      final minutes = c['duration_minutes'] as int;
+      final shouldAccept = c['accepted'] as bool;
+      final error = validateManualWorkout(_draft(minutes));
+      expect(
+        error == null,
+        shouldAccept,
+        reason:
+            '$minutes min should be ${shouldAccept ? "accepted" : "rejected"}, '
+            'got $error',
+      );
+    }
+  });
+
+  test('the rejection message advertises 40 and never the real cutoff', () {
+    final error = validateManualWorkout(_draft(10));
+    expect(error, isNotNull);
+    expect(error, contains('$kMinWorkoutDurationMinutes'));
+    expect(error, isNot(contains('$kWorkoutDurationAcceptMinutes')));
+  });
+}
diff --git a/stronglift_replacement/workout_app/test/screens/home_screen_test.dart b/stronglift_replacement/workout_app/test/screens/home_screen_test.dart
index e4d5991..e0fc237 100644
--- a/stronglift_replacement/workout_app/test/screens/home_screen_test.dart
+++ b/stronglift_replacement/workout_app/test/screens/home_screen_test.dart
@@ -1,3 +1,5 @@
+import 'dart:async';
+
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:sqflite_common_ffi/sqflite_ffi.dart';
@@ -5,7 +7,9 @@ import 'package:workout_app/models/workout_plan.dart';
 import 'package:workout_app/screens/home_screen.dart';
 import 'package:workout_app/screens/workout_screen.dart';
 import 'package:workout_app/services/storage_service.dart';
+import 'package:workout_app/services/workout_sync_service.dart';
 import 'package:workout_app/ui/theme.dart';
+import 'package:workout_app/widgets/sync_status_card.dart';
 
 import '../fake_secure_storage.dart';
 
@@ -30,8 +34,18 @@ void main() {
     await tester.pump();
   }
 
-  Widget _wrap() =>
-      MaterialApp(theme: buildAppTheme(), home: const HomeScreen());
+  // The home screen syncs in the background on every open. Left to itself
+  // that reaches FlutterSecureStorage, whose platform channel throws under
+  // `flutter test`, so every test here would fail on a MissingPluginException
+  // that has nothing to do with what it is asserting. Report "not
+  // configured" instead: no credentials means no sync tick is attempted.
+  Widget _wrap({Future<bool> Function()? configuredProbe}) => MaterialApp(
+    theme: buildAppTheme(),
+    home: HomeScreen(
+      configuredProbe: configuredProbe ?? () async => false,
+      clock: () => DateTime(2026, 8, 15, 18),
+    ),
+  );
 
   testWidgets('shows Workout Tracker app bar', (tester) async {
     await _pump(tester, _wrap());
@@ -190,4 +204,180 @@ void main() {
     await tester.pump(const Duration(milliseconds: 300));
     expect(find.text('Workout Tracker'), findsOneWidget);
   });
+
+  group('sync status card', () {
+    testWidgets('an unconfigured device is warned before it works out', (
+      tester,
+    ) async {
+      await _pump(tester, _wrap(configuredProbe: () async => false));
+      expect(find.byType(SyncStatusCard), findsOneWidget);
+      expect(find.text('Not connected to sync'), findsOneWidget);
+    });
+
+    testWidgets('the card sits ABOVE the workout card', (tester) async {
+      await _pump(tester, _wrap(configuredProbe: () async => false));
+      // The whole point of the placement: the warning has to be read before
+      // the workout starts, not discovered after it failed to count.
+      final cardY = tester.getTopLeft(find.byType(SyncStatusCard)).dy;
+      final workoutY = tester.getTopLeft(find.text('Start Workout A')).dy;
+      expect(cardY, lessThan(workoutY));
+    });
+
+    testWidgets('a failing sync surfaces the reason on the card', (
+      tester,
+    ) async {
+      installFakeSecureStorage();
+      await _pump(
+        tester,
+        MaterialApp(
+          theme: buildAppTheme(),
+          home: HomeScreen(
+            configuredProbe: () async => true,
+            syncService: _FailingSyncService(),
+            clock: () => DateTime(2026, 8, 15, 18),
+          ),
+        ),
+      );
+      expect(find.text('Sync failed'), findsOneWidget);
+      expect(find.textContaining('no network'), findsOneWidget);
+    });
+
+    testWidgets('a phone that has not synced for days says so, before the tick',
+        (tester) async {
+      // Regression: computing the status only AFTER the tick made
+      // SyncState.outOfDate unreachable in the running app -- a success
+      // stamps the time (age 0 -> Synced) and a failure shows Sync failed,
+      // so a stale phone silently looked healthy.
+      installFakeSecureStorage();
+      final now = DateTime(2026, 8, 15, 18);
+      await tester.runAsync(() async {
+        await StorageService.instance.markSyncedNow(
+          now.subtract(const Duration(days: 3)),
+        );
+      });
+      await _pump(
+        tester,
+        MaterialApp(
+          theme: buildAppTheme(),
+          home: HomeScreen(
+            configuredProbe: () async => true,
+            syncService: _HangingSyncService(),
+            clock: () => now,
+          ),
+        ),
+      );
+      expect(find.text('Sync out of date'), findsOneWidget);
+      expect(find.textContaining('3d ago'), findsOneWidget);
+    });
+
+    testWidgets('Set up sync opens Settings so the user can fix it', (
+      tester,
+    ) async {
+      installFakeSecureStorage(); // SettingsScreen reads the token on init
+      await _pump(tester, _wrap(configuredProbe: () async => false));
+      await tester.tap(find.text('Set up sync'));
+      await tester.pump();
+      await tester.pump(const Duration(milliseconds: 300));
+      // The card must lead somewhere: telling the user sync is broken and
+      // leaving them to find Settings is the silence this whole card fixes.
+      expect(find.text('Settings'), findsOneWidget);
+
+      // Coming back re-checks sync, so connecting there clears the card
+      // without needing an app restart.
+      await tester.runAsync(() async {
+        tester.state<NavigatorState>(find.byType(Navigator).last).pop();
+        await Future<void>.delayed(const Duration(milliseconds: 300));
+      });
+      await tester.pump();
+      await tester.pump(const Duration(milliseconds: 300));
+      expect(find.text('Workout Tracker'), findsOneWidget);
+    });
+
+    testWidgets('Retry runs another sync tick', (tester) async {
+      installFakeSecureStorage();
+      var ticks = 0;
+      await _pump(
+        tester,
+        MaterialApp(
+          theme: buildAppTheme(),
+          home: HomeScreen(
+            configuredProbe: () async => true,
+            syncService: _CountingSyncService(() => ticks++),
+            clock: () => DateTime(2026, 8, 15, 18),
+          ),
+        ),
+      );
+      expect(ticks, 1); // the automatic tick on open
+      await tester.runAsync(() async {
+        await tester.tap(find.text('Retry'));
+        await Future<void>.delayed(const Duration(milliseconds: 200));
+      });
+      await tester.pump();
+      expect(ticks, 2);
+    });
+
+    testWidgets('a successful sync stamps the time and shows Synced', (
+      tester,
+    ) async {
+      installFakeSecureStorage();
+      final now = DateTime(2026, 8, 15, 18);
+      await _pump(
+        tester,
+        MaterialApp(
+          theme: buildAppTheme(),
+          home: HomeScreen(
+            configuredProbe: () async => true,
+            syncService: _OkSyncService(),
+            clock: () => now,
+          ),
+        ),
+      );
+      expect(find.textContaining('Synced'), findsOneWidget);
+      // The timestamp must actually persist, or the card would go stale
+      // again on the very next open. Read it inside runAsync: the DB is real
+      // I/O, and awaiting it under FakeAsync hangs the test.
+      DateTime? stamped;
+      await tester.runAsync(() async {
+        stamped = await StorageService.instance.getLastSyncedAt();
+      });
+      expect(stamped, now);
+    });
+  });
+}
+
+/// A sync service whose tick always fails, with a reason worth showing.
+class _FailingSyncService extends WorkoutSyncService {
+  @override
+  Future<PushResult> syncNow() async =>
+      const PushResult(pushed: false, reason: 'sync failed: no network');
+}
+
+/// A sync service whose tick always succeeds.
+class _OkSyncService extends WorkoutSyncService {
+  @override
+  Future<PushResult> syncNow() async =>
+      const PushResult(pushed: true, reason: 'synced');
+}
+
+/// A sync service whose tick never resolves, holding the card on whatever
+/// the persisted state said — which is how a real slow network behaves.
+class _HangingSyncService extends WorkoutSyncService {
+  @override
+  Future<PushResult> syncNow() => Completer<PushResult>().future;
+}
+
+/// A sync service that counts how many ticks it was asked for.
+class _CountingSyncService extends WorkoutSyncService {
+  _CountingSyncService(this.onTick);
+
+  /// Called once per [syncNow].
+  final void Function() onTick;
+
+  @override
+  Future<PushResult> syncNow() async {
+    onTick();
+    // Fail, so the card keeps offering Retry instead of collapsing to the
+    // button-less healthy state after the first tick.
+    return const PushResult(pushed: false, reason: 'sync failed: offline');
+  }
 }
diff --git a/stronglift_replacement/workout_app/test/services/storage_service_test.dart b/stronglift_replacement/workout_app/test/services/storage_service_test.dart
index 60f498e..c7b21e2 100644
--- a/stronglift_replacement/workout_app/test/services/storage_service_test.dart
+++ b/stronglift_replacement/workout_app/test/services/storage_service_test.dart
@@ -711,4 +711,49 @@ void main() {
       expect(await _svc.getWorkoutHistory(), isEmpty);
     });
   });
+
+  // ── Last-sync timestamp (drives the home screen's status card) ─────────────
+
+  group('last synced at', () {
+    test('is null before a sync has ever succeeded', () async {
+      expect(await _svc.getLastSyncedAt(), isNull);
+    });
+
+    test('round-trips the time a sync succeeded', () async {
+      final at = DateTime(2026, 8, 15, 18, 30);
+      await _svc.markSyncedNow(at);
+      expect(await _svc.getLastSyncedAt(), at);
+    });
+
+    test('defaults to now when no time is given', () async {
+      final before = DateTime.now().subtract(const Duration(seconds: 1));
+      await _svc.markSyncedNow();
+      final stored = await _svc.getLastSyncedAt();
+      expect(stored, isNotNull);
+      expect(stored!.isAfter(before), isTrue);
+    });
+
+    test('a corrupt stored value reads as never-synced, loudly', () async {
+      // Seed a garbage timestamp directly: getLastSyncedAt must not throw,
+      // and must say why rather than silently showing the nag card forever.
+      final dir = await Directory.systemTemp.createTemp('mw_badstamp');
+      final dbFile = p.join(dir.path, 'bad.db');
+      StorageService.resetForTesting(dbPath: dbFile);
+      await StorageService.init();
+      await _svc.markSyncedNow(DateTime(2026, 8, 15));
+
+      final db = await databaseFactory.openDatabase(dbFile);
+      await db.update(
+        'settings',
+        {'value': 'not-a-timestamp'},
+        where: 'key = ?',
+        whereArgs: ['last_synced_at'],
+      );
+      await db.close();
+
+      StorageService.resetForTesting(dbPath: dbFile);
+      await StorageService.init();
+      expect(await _svc.getLastSyncedAt(), isNull);
+    });
+  });
 }
diff --git a/stronglift_replacement/workout_app/test/services/sync_status_test.dart b/stronglift_replacement/workout_app/test/services/sync_status_test.dart
new file mode 100644
index 0000000..76cf73f
--- /dev/null
+++ b/stronglift_replacement/workout_app/test/services/sync_status_test.dart
@@ -0,0 +1,99 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:workout_app/services/sync_status.dart';
+import 'package:workout_app/services/workout_sync_service.dart';
+
+final _now = DateTime(2026, 8, 15, 18);
+
+void main() {
+  group('computeSyncStatus', () {
+    test('no credentials wins even with a fresh timestamp', () {
+      // Ordering matters: a device with no credentials must be told to set
+      // sync up, not that it is merely stale.
+      final status = computeSyncStatus(
+        configured: false,
+        now: _now,
+        lastSyncedAt: _now.subtract(const Duration(minutes: 1)),
+      );
+      expect(status.state, SyncState.notConnected);
+    });
+
+    test('first run — no credentials AND no timestamp — is notConnected', () {
+      final status = computeSyncStatus(configured: false, now: _now);
+      expect(status.state, SyncState.notConnected);
+    });
+
+    test('a failed attempt beats a fresh timestamp', () {
+      final status = computeSyncStatus(
+        configured: true,
+        now: _now,
+        lastResult: const PushResult(pushed: false, reason: 'boom'),
+        lastSyncedAt: _now.subtract(const Duration(minutes: 1)),
+      );
+      expect(status.state, SyncState.failed);
+      expect(status.reason, 'boom');
+    });
+
+    test('configured but never synced is outOfDate with no age', () {
+      final status = computeSyncStatus(configured: true, now: _now);
+      expect(status.state, SyncState.outOfDate);
+      expect(status.age, isNull);
+    });
+
+    test('exactly at the staleness boundary is outOfDate', () {
+      final status = computeSyncStatus(
+        configured: true,
+        now: _now,
+        lastSyncedAt: _now.subtract(kSyncStaleAfter),
+      );
+      expect(status.state, SyncState.outOfDate);
+      expect(status.age, kSyncStaleAfter);
+    });
+
+    test('just inside the staleness boundary is synced', () {
+      final status = computeSyncStatus(
+        configured: true,
+        now: _now,
+        lastSyncedAt: _now.subtract(
+          kSyncStaleAfter - const Duration(minutes: 1),
+        ),
+      );
+      expect(status.state, SyncState.synced);
+    });
+
+    test('a successful result with a fresh timestamp is synced', () {
+      final status = computeSyncStatus(
+        configured: true,
+        now: _now,
+        lastResult: const PushResult(pushed: true, reason: 'synced'),
+        lastSyncedAt: _now.subtract(const Duration(minutes: 3)),
+      );
+      expect(status.state, SyncState.synced);
+      expect(status.age, const Duration(minutes: 3));
+    });
+  });
+
+  group('SyncStatus value semantics', () {
+    test('equal fields compare equal and hash alike', () {
+      const a = SyncStatus(state: SyncState.failed, reason: 'x');
+      const b = SyncStatus(state: SyncState.failed, reason: 'x');
+      expect(a, b);
+      expect(a.hashCode, b.hashCode);
+    });
+
+    test('differing fields compare unequal', () {
+      const a = SyncStatus(state: SyncState.failed, reason: 'x');
+      const b = SyncStatus(state: SyncState.failed, reason: 'y');
+      const c = SyncStatus(state: SyncState.synced, reason: 'x');
+      expect(a, isNot(b));
+      expect(a, isNot(c));
+      expect(a, isNot(const SyncStatus(state: SyncState.failed, reason: 'x',
+          age: Duration(seconds: 1))));
+    });
+
+    test('toString names the state and reason', () {
+      const status = SyncStatus(state: SyncState.failed, reason: 'boom');
+      expect(status.toString(), contains('failed'));
+      expect(status.toString(), contains('boom'));
+    });
+  });
+}
diff --git a/stronglift_replacement/workout_app/test/services/workout_sync_service_test.dart b/stronglift_replacement/workout_app/test/services/workout_sync_service_test.dart
index 69e59e9..ec457ef 100644
--- a/stronglift_replacement/workout_app/test/services/workout_sync_service_test.dart
+++ b/stronglift_replacement/workout_app/test/services/workout_sync_service_test.dart
@@ -96,6 +96,7 @@ WorkoutSyncService _service({
 
 void main() {
   _cutoverTests();
+  _manualWorkoutSurvivalTests();
   // installFakeSecureStorage touches the test binary messenger, which needs
   // the binding up first (widget tests get this for free via testWidgets).
   TestWidgetsFlutterBinding.ensureInitialized();
@@ -518,6 +519,155 @@ void main() {
   return (client: client, puts: puts);
 }
 
+/// Regression tests for the one thing that went RIGHT on 2026-08-15.
+///
+/// A manual workout was logged while the phone was disconnected. When
+/// Firebase later connected, the entry was NOT erased -- the user called this
+/// out as good behaviour worth keeping. It is currently correct by
+/// construction (`MirrorStore.getFileText` falls through to the GitHub mirror
+/// when the Firebase primary returns null, so a first connect reads the prior
+/// log rather than an empty one), which is exactly why it needs pinning:
+/// nothing else would fail if that fall-through were removed.
+void _manualWorkoutSurvivalTests() {
+  group('connecting to Firebase does not erase local manual workouts', () {
+    /// A manual record already in this device's log, logged while offline.
+    Record priorManual() => Record(
+      id: 'manual:2026-08-01T10:00',
+      fields: {
+        'payload': (
+          {'kind': 'manual_workout', 'date': '2026-08-01'},
+          Hlc.newTick('phone'),
+        ),
+      },
+    );
+
+    Map<String, dynamic> decodeLogPut(List<_PutCall> calls) =>
+        jsonDecode(
+              utf8.decode(
+                base64.decode(_logPut(calls).body['content'] as String),
+              ),
+            )
+            as Map<String, dynamic>;
+
+    test('a first Firebase connect keeps a manual record only GitHub has',
+        () async {
+      installFakeSecureStorage(initial: {'sync.token': 'tok'});
+      final existingLog = jsonEncode({
+        priorManual().id: priorManual().toJson(),
+      });
+      final (:httpClient, :putCalls) = _mockGitHub(
+        contentResponses: {
+          'screen-locker-sync/devices': _response(200, []),
+          'screen-locker-sync/devices/phone/log.json': _fileContaining(
+            existingLog,
+          ),
+        },
+      );
+      // Firebase answers 'null' to every GET -- the fresh-connect state, and
+      // the exact condition under which a naive implementation would treat
+      // the remote as empty and overwrite the log with just the new record.
+      final firebase = _fakeFirebase();
+
+      final newManual = Record(
+        id: 'manual:2026-08-15T12:18',
+        fields: {
+          'payload': (
+            {'kind': 'manual_workout', 'date': '2026-08-15'},
+            Hlc.newTick('phone'),
+          ),
+        },
+      );
+      final result = await _service(
+        httpClient: httpClient,
+        firebaseFactory: () async => firebase.client,
+      ).pushManual(newManual);
+
+      expect(result.pushed, isTrue);
+      final pushedLog = decodeLogPut(putCalls);
+      expect(
+        pushedLog.keys,
+        containsAll([priorManual().id, newManual.id]),
+        reason: 'the offline-logged manual workout must survive the connect',
+      );
+    });
+
+    test('syncNow reports "not configured" rather than pretending to work',
+        () async {
+      installFakeSecureStorage();
+      final (:httpClient, :putCalls) = _mockGitHub();
+
+      final result = await _service(httpClient: httpClient).syncNow();
+
+      expect(putCalls, isEmpty);
+      expect(result.pushed, isFalse);
+      // The card renders this reason, so it has to name the actual problem.
+      expect(result.reason, contains('not configured'));
+    });
+
+    test('syncNow works on a device with no log yet', () async {
+      // Nothing to preserve on a brand-new device: the tick must still
+      // succeed rather than failing on the absent log.
+      installFakeSecureStorage(initial: {'sync.token': 'tok'});
+      final (:httpClient, :putCalls) = _mockGitHub(
+        contentResponses: {'screen-locker-sync/devices': _response(200, [])},
+      );
+
+      final result = await _service(httpClient: httpClient).syncNow();
+
+      expect(result.pushed, isTrue);
+      expect(result.reason, 'synced');
+    });
+
+    test('syncNow reports the reason when the round trip fails', () async {
+      installFakeSecureStorage(initial: {'sync.token': 'tok'});
+      final httpClient = http_testing.MockClient(
+        (request) async => http.Response('', 500),
+      );
+
+      final result = await _service(httpClient: httpClient).syncNow();
+
+      // Never throws into the UI, but never silent either: this string is
+      // exactly what the "Sync failed" card shows the user.
+      expect(result.pushed, isFalse);
+      expect(result.reason, contains('sync failed'));
+    });
+
+    test('a plain sync tick on first connect does not drop the log', () async {
+      // syncNow() pushes no new record, so if the fresh-connect read came
+      // back empty this would write an EMPTY log over a good one -- the
+      // worst version of the bug, triggered just by opening the app.
+      installFakeSecureStorage(initial: {'sync.token': 'tok'});
+      final existingLog = jsonEncode({
+        priorManual().id: priorManual().toJson(),
+      });
+      final (:httpClient, :putCalls) = _mockGitHub(
+        contentResponses: {
+          'screen-locker-sync/devices': _response(200, []),
+          'screen-locker-sync/devices/phone/log.json': _fileContaining(
+            existingLog,
+          ),
+        },
+      );
+      final firebase = _fakeFirebase();
+
+      final result = await _service(
+        httpClient: httpClient,
+        firebaseFactory: () async => firebase.client,
+      ).syncNow();
+
+      expect(result.pushed, isTrue);
+      final logPuts = putCalls.where((c) => c.path.endsWith('log.json'));
+      if (logPuts.isNotEmpty) {
+        expect(
+          decodeLogPut(putCalls).keys,
+          contains(priorManual().id),
+          reason: 'a no-op tick must never blank the log',
+        );
+      }
+    });
+  });
+}
+
 void _cutoverTests() {
   group('Firebase cutover', () {
     test('pushes to Firebase and still mirrors to GitHub', () async {
diff --git a/stronglift_replacement/workout_app/test/widget_test.dart b/stronglift_replacement/workout_app/test/widget_test.dart
index 24638e1..30b951d 100644
--- a/stronglift_replacement/workout_app/test/widget_test.dart
+++ b/stronglift_replacement/workout_app/test/widget_test.dart
@@ -5,6 +5,8 @@ import 'package:workout_app/main.dart';
 import 'package:workout_app/services/http_server_service.dart';
 import 'package:workout_app/services/storage_service.dart';
 
+import 'fake_secure_storage.dart';
+
 void main() {
   setUpAll(() {
     sqfliteFfiInit();
@@ -12,6 +14,12 @@ void main() {
   });
 
   setUp(() async {
+    // These tests build the whole WorkoutApp, so they cannot inject a sync
+    // probe the way home_screen_test does. The home screen now syncs in the
+    // background on open, which reaches FlutterSecureStorage -- whose real
+    // platform channel throws under `flutter test`. Install the fake instead
+    // of letting an unrelated MissingPluginException fail these.
+    installFakeSecureStorage();
     StorageService.resetForTesting();
     await StorageService.init();
   });
diff --git a/stronglift_replacement/workout_app/test/widgets/sync_status_card_test.dart b/stronglift_replacement/workout_app/test/widgets/sync_status_card_test.dart
new file mode 100644
index 0000000..f9d83e6
--- /dev/null
+++ b/stronglift_replacement/workout_app/test/widgets/sync_status_card_test.dart
@@ -0,0 +1,112 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:workout_app/services/sync_status.dart';
+import 'package:workout_app/ui/theme.dart';
+import 'package:workout_app/widgets/sync_status_card.dart';
+
+void main() {
+  var retried = 0;
+  var setUpTapped = 0;
+
+  setUp(() {
+    retried = 0;
+    setUpTapped = 0;
+  });
+
+  Widget wrap(SyncStatus status) => MaterialApp(
+    theme: buildAppTheme(),
+    home: Scaffold(
+      body: SyncStatusCard(
+        status: status,
+        onRetry: () => retried++,
+        onSetUp: () => setUpTapped++,
+      ),
+    ),
+  );
+
+  testWidgets('notConnected says the workout will not count and offers setup', (
+    tester,
+  ) async {
+    await tester.pumpWidget(
+      wrap(const SyncStatus(state: SyncState.notConnected)),
+    );
+    expect(find.text('Not connected to sync'), findsOneWidget);
+    // The consequence is the whole point of the card -- a workout logged
+    // while disconnected does not count, which is what cost a real session.
+    expect(find.textContaining('NOT count'), findsOneWidget);
+    await tester.tap(find.text('Set up sync'));
+    expect(setUpTapped, 1);
+    expect(retried, 0);
+  });
+
+  testWidgets('failed shows the concrete reason and retries', (tester) async {
+    await tester.pumpWidget(
+      wrap(
+        const SyncStatus(
+          state: SyncState.failed,
+          reason: 'sync failed: connection refused',
+        ),
+      ),
+    );
+    expect(find.text('Sync failed'), findsOneWidget);
+    expect(find.textContaining('connection refused'), findsOneWidget);
+    await tester.tap(find.text('Retry'));
+    expect(retried, 1);
+  });
+
+  testWidgets('failed falls back to generic text when reason is null', (
+    tester,
+  ) async {
+    await tester.pumpWidget(wrap(const SyncStatus(state: SyncState.failed)));
+    expect(find.textContaining('did not go through'), findsOneWidget);
+  });
+
+  testWidgets('outOfDate reports how long ago and retries', (tester) async {
+    await tester.pumpWidget(
+      wrap(
+        const SyncStatus(
+          state: SyncState.outOfDate,
+          age: Duration(hours: 9),
+        ),
+      ),
+    );
+    expect(find.text('Sync out of date'), findsOneWidget);
+    expect(find.textContaining('9h ago'), findsOneWidget);
+    await tester.tap(find.text('Retry'));
+    expect(retried, 1);
+  });
+
+  testWidgets('outOfDate with no age says it has never synced', (tester) async {
+    await tester.pumpWidget(
+      wrap(const SyncStatus(state: SyncState.outOfDate)),
+    );
+    expect(find.textContaining('never synced'), findsOneWidget);
+  });
+
+  testWidgets('synced is a compact line with no button', (tester) async {
+    await tester.pumpWidget(
+      wrap(
+        const SyncStatus(state: SyncState.synced, age: Duration(minutes: 3)),
+      ),
+    );
+    expect(find.textContaining('Synced 3m ago'), findsOneWidget);
+    // Healthy state must not carry an action: a card that is always there
+    // with a button becomes wallpaper and stops being read.
+    expect(find.byType(TextButton), findsNothing);
+    expect(find.byType(Card), findsNothing);
+  });
+
+  testWidgets('synced with no age still renders', (tester) async {
+    await tester.pumpWidget(wrap(const SyncStatus(state: SyncState.synced)));
+    expect(find.text('Synced'), findsOneWidget);
+  });
+
+  group('describeAge', () {
+    test('renders each magnitude the way a human would say it', () {
+      expect(SyncStatusCard.describeAge(const Duration(seconds: 5)), 'just now');
+      expect(SyncStatusCard.describeAge(const Duration(minutes: 5)), '5m ago');
+      expect(SyncStatusCard.describeAge(const Duration(hours: 5)), '5h ago');
+      expect(SyncStatusCard.describeAge(const Duration(days: 5)), '5d ago');
+    });
+  });
+}