diff --git a/OutlineKit/Sources/OutlineKit/Caching/CachingOutlineAPIClient.swift b/OutlineKit/Sources/OutlineKit/Caching/CachingOutlineAPIClient.swift
index 9e39a7e..d62dca6 100644
--- a/OutlineKit/Sources/OutlineKit/Caching/CachingOutlineAPIClient.swift
+++ b/OutlineKit/Sources/OutlineKit/Caching/CachingOutlineAPIClient.swift
@@ -364,10 +364,23 @@ public actor CachingOutlineAPIClient: OutlineAPIClient {
         var documentsCount = 0
         var errors: [String] = []
         var collections: [OutlineCollection] = []
-        do {
-            collections = try await listCollections(offset: 0, limit: 250)
-        } catch {
-            errors.append(errorDescription(error))
+        var collectionsOffset = 0
+        let collectionsLimit = 100
+        // Outline rejects any `limit` over 100 outright — page in increments
+        // of that instead of guessing a total up front (the protocol doesn't
+        // expose `pagination`'s total count, only the page itself); a page
+        // shorter than the limit is what signals "that was the last one".
+        while true {
+            let page: [OutlineCollection]
+            do {
+                page = try await listCollections(offset: collectionsOffset, limit: collectionsLimit)
+            } catch {
+                errors.append(errorDescription(error))
+                break
+            }
+            collections.append(contentsOf: page)
+            guard page.count == collectionsLimit else { break }
+            collectionsOffset += collectionsLimit
         }
 
         for collection in collections {
diff --git a/OutlineKit/Tests/OutlineKitTests/CachingOutlineAPIClientTests.swift b/OutlineKit/Tests/OutlineKitTests/CachingOutlineAPIClientTests.swift
index f53b18e..a5ab991 100644
--- a/OutlineKit/Tests/OutlineKitTests/CachingOutlineAPIClientTests.swift
+++ b/OutlineKit/Tests/OutlineKitTests/CachingOutlineAPIClientTests.swift
@@ -12,6 +12,7 @@ private final class StubOutlineAPIClient: OutlineAPIClient, @unchecked Sendable
     var updateDocumentHandler: (@Sendable (UpdateDocumentRequest) async throws -> OutlineDocument)?
     var createPinHandler: (@Sendable (CreatePinRequest) async throws -> OutlinePin)?
     var deletePinHandler: (@Sendable (String) async throws -> Void)?
+    var listDocumentsHandler: (@Sendable (String?, String?, Int, Int) async throws -> [OutlineDocument])?
 
     func authInfo() async throws -> OutlineAuthInfo { throw NotStubbed() }
 
@@ -21,7 +22,8 @@ private final class StubOutlineAPIClient: OutlineAPIClient, @unchecked Sendable
     }
 
     func listDocuments(collectionId: String?, parentDocumentId: String?, offset: Int, limit: Int) async throws -> [OutlineDocument] {
-        throw NotStubbed()
+        guard let handler = listDocumentsHandler else { throw NotStubbed() }
+        return try await handler(collectionId, parentDocumentId, offset, limit)
     }
 
     func documentsList(_ request: DocumentsListRequest) async throws -> [OutlineDocument] { throw NotStubbed() }
@@ -339,4 +341,48 @@ final class CachingOutlineAPIClientTests: XCTestCase {
         let clearedSummary = await sut.cacheStorageSummary()
         XCTAssertEqual(clearedSummary.itemCount, 0)
     }
+
+    // MARK: - Full sync
+
+    func testPerformFullSyncNeverRequestsMoreThan100CollectionsPerPage() async throws {
+        let stub = StubOutlineAPIClient()
+        var requestedLimits: [Int] = []
+        // 105 collections across two pages (100 + 5) — regression test for a
+        // real bug: this used to ask for `limit: 250` in one shot, which
+        // Outline's server rejects outright ("Pagination limit is too large
+        // (max 100)"), turning the whole sync into a single silent failure.
+        stub.listCollectionsHandler = { offset, limit in
+            requestedLimits.append(limit)
+            let remaining = max(0, 105 - offset)
+            let count = min(limit, remaining)
+            return (0..<count).map { self.makeCollection(id: "col-\(offset + $0)") }
+        }
+        stub.listDocumentsHandler = { _, _, _, _ in [] }
+        let sut = CachingOutlineAPIClient(live: stub, cache: try makeCache())
+
+        let summary = await sut.performFullSync()
+
+        XCTAssertEqual(summary.collectionsCount, 105)
+        XCTAssertTrue(summary.errors.isEmpty)
+        XCTAssertTrue(requestedLimits.allSatisfy { $0 <= 100 }, "requested limits: \(requestedLimits)")
+    }
+
+    func testPerformFullSyncCachesEachDocumentIndividually() async throws {
+        let stub = StubOutlineAPIClient()
+        stub.listCollectionsHandler = { offset, _ in offset == 0 ? [self.makeCollection(id: "col-1")] : [] }
+        stub.listDocumentsHandler = { _, _, offset, _ in
+            offset == 0 ? [self.makeDocument(id: "doc-1"), self.makeDocument(id: "doc-2")] : []
+        }
+        let cache = try makeCache()
+        let sut = CachingOutlineAPIClient(live: stub, cache: cache)
+
+        let summary = await sut.performFullSync()
+        XCTAssertEqual(summary.documentsCount, 2)
+
+        // A plain documentInfo read (no live call available) should now hit
+        // the cache full sync populated, not just the list-shaped cache key.
+        stub.documentInfoHandler = { _ in throw StubTransportError() }
+        let cachedDoc = try await sut.documentInfo(id: "doc-2")
+        XCTAssertEqual(cachedDoc.id, "doc-2")
+    }
 }
diff --git a/Outpost/Features/Collections/ContentView_macOS.swift b/Outpost/Features/Collections/ContentView_macOS.swift
index e568151..57a4e22 100644
--- a/Outpost/Features/Collections/ContentView_macOS.swift
+++ b/Outpost/Features/Collections/ContentView_macOS.swift
@@ -5,6 +5,7 @@ import OutlineKit
 struct ContentView_macOS: View {
     @Environment(SessionStore.self) private var session
     @Environment(AppNavigation.self) private var navigation
+    @AppStorage(CachingOutlineAPIClient.offlineModeDefaultsKey) private var isOfflineModeEnabled = false
     /// The landing state — no collection selected yet is what Home actually
     /// means, so this starts `true` rather than auto-selecting the first
     /// collection the way this used to work.
@@ -50,8 +51,8 @@ struct ContentView_macOS: View {
                     VStack(spacing: 0) {
                         SidebarSearchField(text: $globalSearchQuery)
                         Divider()
-                        if !session.networkMonitor.isOnline {
-                            OfflineBanner()
+                        if isOfflineModeEnabled || !session.networkMonitor.isOnline {
+                            OfflineBanner(isManual: isOfflineModeEnabled)
                             Divider()
                         }
                         sidebar
diff --git a/Outpost/Features/Collections/OfflineBanner.swift b/Outpost/Features/Collections/OfflineBanner.swift
index 8229c52..24cafbc 100644
--- a/Outpost/Features/Collections/OfflineBanner.swift
+++ b/Outpost/Features/Collections/OfflineBanner.swift
@@ -1,15 +1,21 @@
 #if os(macOS)
 import SwiftUI
 
-/// Shown at the top of the sidebar whenever `NetworkMonitor` reports no
-/// connection — cached collections/documents keep browsing working, but the
-/// user should know they might be looking at stale data.
+/// Shown at the top of the sidebar whenever the app is offline — either for
+/// real (`NetworkMonitor` reports no connection) or because the user turned
+/// on the manual "Offline Mode" toggle. Cached collections/documents keep
+/// browsing working either way, but the user should know they might be
+/// looking at stale data.
 struct OfflineBanner: View {
+    /// Whether this is the user's own "Offline Mode" toggle rather than a
+    /// real dropped connection — same banner slot, different explanation.
+    var isManual: Bool = false
+
     var body: some View {
         HStack(spacing: 8) {
             Image(systemName: "wifi.slash")
                 .foregroundStyle(.orange)
-            Text("Offline — showing cached content")
+            Text(isManual ? "Offline Mode — showing cached content" : "Offline — showing cached content")
                 .font(.callout)
             Spacer(minLength: 0)
         }
diff --git a/Outpost/Support/NetworkMonitor.swift b/Outpost/Support/NetworkMonitor.swift
index 1c37dd9..35fc64d 100644
--- a/Outpost/Support/NetworkMonitor.swift
+++ b/Outpost/Support/NetworkMonitor.swift
@@ -14,10 +14,17 @@ final class NetworkMonitor {
     private let queue = DispatchQueue(label: "com.outpost.network-monitor")
 
     init() {
-        monitor.pathUpdateHandler = { path in
+        // Weak on the outer closure (it's held by `monitor` for the object's
+        // whole lifetime, so a strong capture here would be a retain cycle),
+        // then unwrapped once into a plain strong local — the inner `Task`
+        // closure capturing that local `self` is what a nested closure needs
+        // to be consistent about capture semantics with its enclosing one.
+        monitor.pathUpdateHandler = { [weak self] path in
+            guard let self else { return }
+     
             let online = path.status == .satisfied
-            Task { @MainActor [weak self] in
-                self?.isOnline = online
+            Task { @MainActor in
+                self.isOnline = online
             }
         }
         monitor.start(queue: queue)