diff --git a/backend/routers/sleep.py b/backend/routers/sleep.py
index 6a7f498..e346a94 100644
--- a/backend/routers/sleep.py
+++ b/backend/routers/sleep.py
@@ -579,7 +579,7 @@ async def import_apple_health_sleep(
                 for seg in night['segments']
             ]
 
-            # Check if manual entry exists
+            # Check if manual entry exists - do NOT overwrite
             cur.execute("""
                 SELECT id, source FROM sleep_log
                 WHERE profile_id = %s AND date = %s
@@ -588,43 +588,63 @@ async def import_apple_health_sleep(
 
             if existing and existing['source'] == 'manual':
                 skipped += 1
-                continue  # Don't overwrite manual entries
+                continue  # Skip - don't overwrite manual entries
 
-            # Upsert
-            cur.execute("""
-                INSERT INTO sleep_log (
-                    profile_id, date, bedtime, wake_time, duration_minutes,
-                    wake_count, deep_minutes, rem_minutes, light_minutes, awake_minutes,
-                    sleep_segments, source, updated_at
-                ) VALUES (
-                    %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, 'apple_health', CURRENT_TIMESTAMP
-                )
-                ON CONFLICT (profile_id, date) DO UPDATE SET
-                    bedtime = EXCLUDED.bedtime,
-                    wake_time = EXCLUDED.wake_time,
-                    duration_minutes = EXCLUDED.duration_minutes,
-                    wake_count = EXCLUDED.wake_count,
-                    deep_minutes = EXCLUDED.deep_minutes,
-                    rem_minutes = EXCLUDED.rem_minutes,
-                    light_minutes = EXCLUDED.light_minutes,
-                    awake_minutes = EXCLUDED.awake_minutes,
-                    sleep_segments = EXCLUDED.sleep_segments,
-                    source = EXCLUDED.source,
-                    updated_at = CURRENT_TIMESTAMP
-                WHERE sleep_log.source != 'manual'
-            """, (
-                pid,
-                date,
-                night['bedtime'].time(),
-                night['wake_time'].time(),
-                duration_minutes,
-                wake_count,
-                night['deep_minutes'],
-                night['rem_minutes'],
-                night['light_minutes'],
-                night['awake_minutes'],
-                json.dumps(sleep_segments)
-            ))
+            # Upsert (only if not manual)
+            # If entry exists and is NOT manual → update
+            # If entry doesn't exist → insert
+            if existing:
+                # Update existing non-manual entry
+                cur.execute("""
+                    UPDATE sleep_log SET
+                        bedtime = %s,
+                        wake_time = %s,
+                        duration_minutes = %s,
+                        wake_count = %s,
+                        deep_minutes = %s,
+                        rem_minutes = %s,
+                        light_minutes = %s,
+                        awake_minutes = %s,
+                        sleep_segments = %s,
+                        source = 'apple_health',
+                        updated_at = CURRENT_TIMESTAMP
+                    WHERE id = %s AND profile_id = %s
+                """, (
+                    night['bedtime'].time(),
+                    night['wake_time'].time(),
+                    duration_minutes,
+                    wake_count,
+                    night['deep_minutes'],
+                    night['rem_minutes'],
+                    night['light_minutes'],
+                    night['awake_minutes'],
+                    json.dumps(sleep_segments),
+                    existing['id'],
+                    pid
+                ))
+            else:
+                # Insert new entry
+                cur.execute("""
+                    INSERT INTO sleep_log (
+                        profile_id, date, bedtime, wake_time, duration_minutes,
+                        wake_count, deep_minutes, rem_minutes, light_minutes, awake_minutes,
+                        sleep_segments, source, created_at, updated_at
+                    ) VALUES (
+                        %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, 'apple_health', CURRENT_TIMESTAMP, CURRENT_TIMESTAMP
+                    )
+                """, (
+                    pid,
+                    date,
+                    night['bedtime'].time(),
+                    night['wake_time'].time(),
+                    duration_minutes,
+                    wake_count,
+                    night['deep_minutes'],
+                    night['rem_minutes'],
+                    night['light_minutes'],
+                    night['awake_minutes'],
+                    json.dumps(sleep_segments)
+                ))
 
             imported += 1
 
diff --git a/frontend/src/pages/SleepPage.jsx b/frontend/src/pages/SleepPage.jsx
index 0b409dc..9f43767 100644
--- a/frontend/src/pages/SleepPage.jsx
+++ b/frontend/src/pages/SleepPage.jsx
@@ -234,6 +234,33 @@ export default function SleepPage() {
         />
       </div>
 
+      {/* Manual Entry Button */}
+      <button
+        onClick={() => setEditingId('new')}
+        className="btn btn-primary btn-full"
+        style={{ marginBottom: 16 }}
+      >
+        <Plus size={16} /> Schlaf erfassen
+      </button>
+
+      {/* New Entry Form (if creating) */}
+      {editingId === 'new' && (
+        <NewEntryForm
+          onSave={async (data) => {
+            try {
+              await api.createSleep(data)
+              await load()
+              setEditingId(null)
+              showToast('Gespeichert')
+            } catch (err) {
+              showToast(err.message, 'error')
+            }
+          }}
+          onCancel={() => setEditingId(null)}
+          formatDuration={formatDuration}
+        />
+      )}
+
       {/* Sleep List */}
       <div style={{ fontWeight: 600, fontSize: 14, marginBottom: 12 }}>
         Letzte 30 Nächte ({sleep.length})
@@ -641,3 +668,259 @@ function SleepEntry({ entry, expanded, editing, onToggleExpand, onEdit, onCancel
     </div>
   )
 }
+
+// ── New Entry Form Component ──────────────────────────────────────────────────
+
+function NewEntryForm({ onSave, onCancel, formatDuration }) {
+  const [formData, setFormData] = useState({
+    date: new Date().toISOString().split('T')[0],
+    duration_minutes: 450, // 7h 30min default
+    quality: 3,
+    bedtime: '',
+    wake_time: '',
+    wake_count: 0,
+    deep_minutes: '',
+    rem_minutes: '',
+    light_minutes: '',
+    awake_minutes: '',
+    note: '',
+    source: 'manual'
+  })
+
+  const [saving, setSaving] = useState(false)
+  const [plausibilityError, setPlausibilityError] = useState(null)
+  const [showDetail, setShowDetail] = useState(false)
+
+  // Live plausibility check
+  useEffect(() => {
+    const phases = [formData.deep_minutes, formData.rem_minutes, formData.light_minutes, formData.awake_minutes]
+    if (phases.some(p => p !== '' && p !== null)) {
+      const sum = phases.reduce((a, b) => a + (parseInt(b) || 0), 0)
+      const diff = Math.abs(formData.duration_minutes - sum)
+      if (diff > 5) {
+        setPlausibilityError(`Phasen-Summe (${sum} min) weicht um ${diff} min ab (Toleranz: 5 min)`)
+      } else {
+        setPlausibilityError(null)
+      }
+    } else {
+      setPlausibilityError(null)
+    }
+  }, [formData])
+
+  const handleSave = async () => {
+    if (plausibilityError) {
+      alert(plausibilityError)
+      return
+    }
+
+    setSaving(true)
+    try {
+      await onSave(formData)
+    } finally {
+      setSaving(false)
+    }
+  }
+
+  return (
+    <div className="card" style={{ padding: 16, marginBottom: 16, border: '2px solid var(--accent)' }}>
+      <div style={{ fontWeight: 600, marginBottom: 12 }}>➕ Neuer Eintrag</div>
+
+      <div style={{ display: 'flex', flexDirection: 'column', gap: 12 }}>
+        <div>
+          <div className="form-label">Datum</div>
+          <input
+            type="date"
+            className="form-input"
+            value={formData.date}
+            onChange={e => setFormData({ ...formData, date: e.target.value })}
+            style={{ width: '100%' }}
+          />
+        </div>
+
+        <div style={{ display: 'grid', gridTemplateColumns: '2fr 1fr', gap: 12 }}>
+          <div>
+            <div className="form-label">Schlafdauer (Minuten)</div>
+            <input
+              type="number"
+              className="form-input"
+              value={formData.duration_minutes}
+              onChange={e => setFormData({ ...formData, duration_minutes: parseInt(e.target.value) || 0 })}
+              style={{ width: '100%' }}
+              min="1"
+            />
+            <div style={{ fontSize: 11, color: 'var(--text3)', marginTop: 4 }}>
+              = {formatDuration(formData.duration_minutes)}
+            </div>
+          </div>
+
+          <div>
+            <div className="form-label">Qualität</div>
+            <select
+              className="form-input"
+              value={formData.quality || ''}
+              onChange={e => setFormData({ ...formData, quality: parseInt(e.target.value) || null })}
+              style={{ width: '100%' }}
+            >
+              <option value="">—</option>
+              <option value="1">★☆☆☆☆ 1</option>
+              <option value="2">★★☆☆☆ 2</option>
+              <option value="3">★★★☆☆ 3</option>
+              <option value="4">★★★★☆ 4</option>
+              <option value="5">★★★★★ 5</option>
+            </select>
+          </div>
+        </div>
+
+        <div>
+          <div className="form-label">Notiz (optional)</div>
+          <textarea
+            className="form-input"
+            value={formData.note}
+            onChange={e => setFormData({ ...formData, note: e.target.value })}
+            placeholder="z.B. 'Gut durchgeschlafen', 'Stress', ..."
+            rows={2}
+            style={{ width: '100%', resize: 'vertical' }}
+          />
+        </div>
+
+        {/* Toggle Detail View */}
+        <button
+          onClick={() => setShowDetail(!showDetail)}
+          className="btn btn-secondary"
+          style={{ fontSize: 12 }}
+        >
+          {showDetail ? '− Detailansicht ausblenden' : '+ Detailansicht anzeigen'}
+        </button>
+
+        {/* Detail Fields */}
+        {showDetail && (
+          <div style={{ display: 'flex', flexDirection: 'column', gap: 12, paddingTop: 12, borderTop: '1px solid var(--border)' }}>
+            <div style={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: 12 }}>
+              <div>
+                <div className="form-label">Eingeschlafen (HH:MM)</div>
+                <input
+                  type="time"
+                  className="form-input"
+                  value={formData.bedtime}
+                  onChange={e => setFormData({ ...formData, bedtime: e.target.value })}
+                  style={{ width: '100%' }}
+                />
+              </div>
+              <div>
+                <div className="form-label">Aufgewacht (HH:MM)</div>
+                <input
+                  type="time"
+                  className="form-input"
+                  value={formData.wake_time}
+                  onChange={e => setFormData({ ...formData, wake_time: e.target.value })}
+                  style={{ width: '100%' }}
+                />
+              </div>
+            </div>
+
+            <div>
+              <div className="form-label">Aufwachungen</div>
+              <input
+                type="number"
+                className="form-input"
+                value={formData.wake_count || 0}
+                onChange={e => setFormData({ ...formData, wake_count: parseInt(e.target.value) || 0 })}
+                style={{ width: '100%' }}
+                min="0"
+              />
+            </div>
+
+            <div style={{ fontWeight: 600, fontSize: 13, marginTop: 8 }}>Schlafphasen (Minuten)</div>
+
+            <div style={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: 12 }}>
+              <div>
+                <div className="form-label">Tiefschlaf</div>
+                <input
+                  type="number"
+                  className="form-input"
+                  value={formData.deep_minutes}
+                  onChange={e => setFormData({ ...formData, deep_minutes: parseInt(e.target.value) || '' })}
+                  placeholder="—"
+                  style={{ width: '100%' }}
+                  min="0"
+                />
+              </div>
+              <div>
+                <div className="form-label">REM-Schlaf</div>
+                <input
+                  type="number"
+                  className="form-input"
+                  value={formData.rem_minutes}
+                  onChange={e => setFormData({ ...formData, rem_minutes: parseInt(e.target.value) || '' })}
+                  placeholder="—"
+                  style={{ width: '100%' }}
+                  min="0"
+                />
+              </div>
+              <div>
+                <div className="form-label">Leichtschlaf</div>
+                <input
+                  type="number"
+                  className="form-input"
+                  value={formData.light_minutes}
+                  onChange={e => setFormData({ ...formData, light_minutes: parseInt(e.target.value) || '' })}
+                  placeholder="—"
+                  style={{ width: '100%' }}
+                  min="0"
+                />
+              </div>
+              <div>
+                <div className="form-label">Wach im Bett</div>
+                <input
+                  type="number"
+                  className="form-input"
+                  value={formData.awake_minutes}
+                  onChange={e => setFormData({ ...formData, awake_minutes: parseInt(e.target.value) || '' })}
+                  placeholder="—"
+                  style={{ width: '100%' }}
+                  min="0"
+                />
+              </div>
+            </div>
+
+            {plausibilityError && (
+              <div style={{ marginTop: 8, padding: 8, background: '#D85A30', color: 'white', borderRadius: 6, fontSize: 11, display: 'flex', alignItems: 'center', gap: 6 }}>
+                <AlertCircle size={14} />
+                {plausibilityError}
+              </div>
+            )}
+          </div>
+        )}
+
+        {/* Action Buttons */}
+        <div style={{ display: 'flex', gap: 8, marginTop: 12 }}>
+          <button
+            onClick={handleSave}
+            disabled={saving || !!plausibilityError}
+            className="btn btn-primary"
+            style={{ flex: 1 }}
+          >
+            {saving ? (
+              <div style={{ display: 'flex', alignItems: 'center', gap: 6, justifyContent: 'center' }}>
+                <div className="spinner" style={{ width: 14, height: 14 }} />
+                Speichere...
+              </div>
+            ) : (
+              <>
+                <Save size={16} /> Speichern
+              </>
+            )}
+          </button>
+          <button
+            onClick={onCancel}
+            disabled={saving}
+            className="btn btn-secondary"
+            style={{ flex: 1 }}
+          >
+            <X size={16} /> Abbrechen
+          </button>
+        </div>
+      </div>
+    </div>
+  )
+}