diff --git a/AGENTS.md b/AGENTS.md
index d9abccd..ecae650 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -94,6 +94,11 @@ Tests cover:
 - `Xorshift64` — same seed → same sequence; different seeds → different sequences
 - `NativeMatrixRenderer` — `seedOffset` defaults to `0`; two renderers with different `seedOffset` values diverge after 60 frames
 
+## README audience
+
+- Change `README.md` only when end-user information changes, such as installation, usage, or compatibility guidance.
+- Keep implementation details and contributor reference in `docs/development.md`, plans in `docs/plans/`, and agent instructions in `AGENTS.md`.
+
 ## Code documentation
 
 Use Swift doc comments (`///`) for all public and internal declarations — types, properties, methods, and parameters. Follow the standard Swift/Xcode documentation style:
diff --git a/README.md b/README.md
index 463900e..f0d6c0d 100644
--- a/README.md
+++ b/README.md
@@ -16,7 +16,7 @@ brew trust --cask patrickschaper/tap/matrix-screen-saver
 brew install --cask patrickschaper/tap/matrix-screen-saver && open "/Applications/Matrix Wallpaper.app"
 ```
 
-- Wallpaper: open **Matrix Wallpaper** in Applications. options available through menubar icon.
+- Wallpaper: open **Matrix Wallpaper** in Applications. Choose **Settings…** from its menu bar icon to customize the animation.
 - Screen saver options: **System Settings → Wallpaper → Screen Saver → MatrixScreenSaver → Options…**.
 
 ## Buy me a coffee
@@ -71,6 +71,8 @@ The bundled [Matrix Code](https://github.com/Rezmason/matrix/raw/master/assets/M
 
 ## Development
 
+See the [project roadmap](docs/plans/2026-11-10-1812-project-roadmap-plan.md) for planned work, including GPU-accelerated 3D scenes.
+
 ### Current state
 
 - Native Swift/AppKit screen saver bundle
@@ -179,34 +181,7 @@ To install and launch the wallpaper app in your user Applications folder:
 open "$HOME/Applications/Matrix Wallpaper.app"
 ```
 
-The installer builds and verifies the app, gracefully quits running copies before
-replacement, and retains preferences. It does not launch the app or enable login startup.
-It migrates a signed `MatrixWallpaper.app` with the matching bundle ID to
-`Matrix Wallpaper.app`, restoring the previous installation if replacement fails.
-Unrelated bundles and symlinks at the old path are left alone. The executable remains
-`MatrixWallpaper` and the bundle ID remains `dev.patsch.MatrixWallpaper`.
-
-When MatrixScreenSaver is installed in `~/Library/Screen Savers` or `/Library/Screen Savers`,
-the wallpaper menu shows **Sync with Screen Saver**. It is checked by default: the saver
-shares the wallpaper's animation. Uncheck it to let the saver animate independently.
-The choice survives app restarts and saver reinstallation; opening the menu refreshes
-installation detection. This does not change visual options or synchronization between monitors.
-
-While Matrix Wallpaper runs, it saves each display's desktop image and display options,
-then sets the underlying wallpaper to plain black. **Stop** and **Pause/Resume** share
-one native menu row. **Pause** freezes the visible frame; **Resume** continues the scene.
-Pausing is session-only and does not persist across launches. With **Sync with Screen Saver**
-enabled, the saver temporarily advances the shared scene even while the wallpaper is paused.
-When the saver exits, the wallpaper pauses again at the updated scene. **Stop** and
-**Quit Matrix Wallpaper** restore the original wallpaper settings. Temporary pauses
-and animation restarts keep the original backup.
-If you choose a different wallpaper while Matrix runs, that newer choice is preserved.
-
-Backups are stored in `~/Library/Application Support/MatrixWallpaper/DesktopWallpaper/`.
-After a crash or force-quit, reopen Matrix Wallpaper and choose **Stop** to restore the desktop.
-Disconnected displays and failed restores keep their backups for a later retry.
-Exact restoration is supported for static images; macOS's public API cannot preserve every
-dynamic/aerial wallpaper, rotating collection, or separate Space configuration.
+See the [developer notes](docs/development.md) for installation internals, version checks, and wallpaper restoration details.
 
 ### Origin
 
diff --git a/Resources/BuyMeACoffee.png b/Resources/BuyMeACoffee.png
new file mode 100644
index 0000000..d7e05d6
Binary files /dev/null and b/Resources/BuyMeACoffee.png differ
diff --git a/Resources/MenuBarIcon.pdf b/Resources/MenuBarIcon.pdf
index 5c15d28..9ca509c 100644
Binary files a/Resources/MenuBarIcon.pdf and b/Resources/MenuBarIcon.pdf differ
diff --git a/Sources/MatrixScreenSaver/MatrixScreenSaverOptions.swift b/Sources/MatrixScreenSaver/MatrixScreenSaverOptions.swift
index e4b2946..e7ffc88 100644
--- a/Sources/MatrixScreenSaver/MatrixScreenSaverOptions.swift
+++ b/Sources/MatrixScreenSaver/MatrixScreenSaverOptions.swift
@@ -328,11 +328,6 @@ struct MatrixScreenSaverOptions: Equatable {
     }
 }
 
-/// A top-origin document keeps the Rain options at the top when its content grows.
-private final class RainOptionsDocumentView: NSView {
-    override var isFlipped: Bool { true }
-}
-
 final class MatrixScreenSaverOptionsSheetController: NSObject,
     NSTextFieldDelegate, NSWindowDelegate,
     NSTableViewDataSource, NSTableViewDelegate {
@@ -368,7 +363,17 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
 
     private let window: NSWindow
     private let rootStack = NSStackView()
-    private let neoMessageSceneCheckbox = NSButton(checkboxWithTitle: "Show Neo message scene", target: nil, action: nil)
+    /// The same detector is used in either host; refreshes never replace pending option edits.
+    private let readVersionStatus: () -> MatrixVersionStatus
+    private var versionStatus: MatrixVersionStatus?
+    private let versionBanner = NSStackView()
+    private let versionHeading = NSTextField(wrappingLabelWithString: "")
+    private let versionDescription = NSTextField(wrappingLabelWithString: "")
+    private let versionSymbol = NSImageView()
+    /// Only the tab content scrolls when the warning would push actions below the screen.
+    private let optionsScrollView = NSScrollView()
+    private var optionsHeight: NSLayoutConstraint?
+    private let neoMessageSceneCheckbox = NSButton(checkboxWithTitle: "Show Neo message", target: nil, action: nil)
     private let neoMessageSpeedFactorField = NSTextField(string: "")
     private let cmdOutputHoldSecondsField = NSTextField(string: "")
     private let nameField = NSTextField(string: "")
@@ -398,7 +403,7 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
     private var maximumEditorRows: Int {
         editingCommands ? MatrixScreenSaverOptions.maxCommandCount : MatrixScreenSaverOptions.maxNeoMessageLineCount
     }
-    private let cmdSceneCheckbox = NSButton(checkboxWithTitle: "Show custom scene", target: nil, action: nil)
+    private let cmdSceneCheckbox = NSButton(checkboxWithTitle: "Run custom commands", target: nil, action: nil)
     /// Scene-owned editor buttons remain available only while their scene is enabled.
     private let commandsEditButton = NSButton(title: "Edit…", target: nil, action: nil)
     private let linesEditButton = NSButton(title: "Edit…", target: nil, action: nil)
@@ -410,7 +415,7 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
     private let commandsShuffleRadio = NSButton(radioButtonWithTitle: "All commands in random order", target: nil, action: nil)
     /// Commands accepted in the editor, not persisted until the main dialog is accepted.
     private var pendingCommands: [String] = []
-    private let numberSceneCheckbox = NSButton(checkboxWithTitle: "Show trace program scene", target: nil, action: nil)
+    private let numberSceneCheckbox = NSButton(checkboxWithTitle: "Show trace program", target: nil, action: nil)
     private let twinkleCheckbox = NSButton(checkboxWithTitle: "Twinkling effect", target: nil, action: nil)
     private let diffuseCheckbox = NSButton(checkboxWithTitle: "Glow effect", target: nil, action: nil)
     private let scanLinesSlider: NSSlider = {
@@ -461,8 +466,13 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
 
     /// Creates native options UI with a host-owned apply action.
     ///
-    /// - Parameter onApply: Receives validated options when the user chooses Apply.
-    init(onApply: @escaping (MatrixScreenSaverOptions) -> Void) {
+    /// - Parameters:
+    ///   - readVersionStatus: Reads companion versions independently of pending preference edits.
+    ///   - onApply: Receives validated options when the user chooses Save.
+    init(readVersionStatus: @escaping () -> MatrixVersionStatus = {
+        MatrixVersionStatus.current(hostBundle: Bundle(for: MatrixScreenSaverOptionsSheetController.self))
+    }, onApply: @escaping (MatrixScreenSaverOptions) -> Void) {
+        self.readVersionStatus = readVersionStatus
         self.onApply = onApply
         window = NSWindow(
             contentRect: NSRect(x: 0, y: 0, width: 1, height: 1),
@@ -510,12 +520,35 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         updateRainGlyphControls()
         rebuildRainFontsMenu()
         updateSceneControls()
-        sizeWindowToFitContent()
     }
 
     /// Returns the native sheet window presented by ScreenSaver.framework.
     func configureSheet() -> NSWindow {
-        window
+        refreshVersionStatus()
+        return window
+    }
+
+    /// Rechecks installations without reloading preferences or disturbing unsaved controls.
+    func refreshVersionStatus() {
+        let status = readVersionStatus()
+        guard status != versionStatus else { return }
+        versionStatus = status
+        versionBanner.isHidden = status.state != .mismatch && status.state != .unverified
+        versionHeading.stringValue = status.title
+        versionDescription.stringValue = status.message
+        versionSymbol.image = status.state == .mismatch ? MatrixVersionStatus.warningImage
+            : NSImage(systemSymbolName: "info.circle", accessibilityDescription: "Version unavailable")
+        versionSymbol.setAccessibilityLabel(status.state == .mismatch ? "Version mismatch" : "Version unavailable")
+        sizeWindowToFitContent()
+    }
+
+    /// Reopening a retained sheet must reflect installations changed while it was inactive.
+    func windowDidBecomeKey(_ notification: Notification) {
+        refreshVersionStatus()
+    }
+
+    @objc private func openReleases(_ sender: Any?) {
+        NSWorkspace.shared.open(MatrixVersionStatus.releasesURL)
     }
 
     /// Validates and applies the edited options.
@@ -556,7 +589,7 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
 
     /// Constructs the native AppKit options sheet content and layout.
     private func buildWindow() {
-        window.title = "Matrix Screen Saver and animated Wallpaper"
+        window.title = "Matrix Options"
         window.isReleasedWhenClosed = false
         window.delegate = self
 
@@ -588,48 +621,94 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         rootStack.edgeInsets = NSEdgeInsets(top: 20, left: 20, bottom: 20, right: 20)
         rootStack.translatesAutoresizingMaskIntoConstraints = false
 
-        let aboutButton = NSButton(title: "About", target: self, action: #selector(openRepository(_:)))
+        versionHeading.font = .boldSystemFont(ofSize: NSFont.systemFontSize)
+        versionDescription.font = .systemFont(ofSize: NSFont.systemFontSize)
+        versionDescription.isSelectable = true
+        let warningText = NSStackView(views: [versionHeading, versionDescription])
+        warningText.orientation = .vertical
+        warningText.alignment = .leading
+        warningText.spacing = 4
+        let releaseButton = NSButton(title: "View Releases…", target: self, action: #selector(openReleases(_:)))
+        warningText.addArrangedSubview(releaseButton)
+        versionBanner.orientation = .horizontal
+        versionBanner.alignment = .top
+        versionBanner.spacing = 12
+        versionBanner.addArrangedSubview(versionSymbol)
+        versionBanner.addArrangedSubview(warningText)
+        versionBanner.isHidden = true
+        rootStack.addArrangedSubview(versionBanner)
+        NSLayoutConstraint.activate([
+            versionBanner.widthAnchor.constraint(equalToConstant: 640),
+            versionSymbol.widthAnchor.constraint(equalToConstant: 24),
+            versionSymbol.heightAnchor.constraint(equalToConstant: 24),
+            warningText.widthAnchor.constraint(equalTo: versionBanner.widthAnchor, constant: -36),
+            versionHeading.widthAnchor.constraint(equalTo: warningText.widthAnchor),
+            versionDescription.widthAnchor.constraint(equalTo: warningText.widthAnchor),
+        ])
+
+        let aboutButton = NSButton(title: "About the project", target: self, action: #selector(openRepository(_:)))
         aboutButton.bezelStyle = .inline
         aboutButton.isBordered = false
         aboutButton.contentTintColor = .linkColor
         aboutButton.font = .systemFont(ofSize: 13)
 
         // Tab pages lay out during insertion, before Auto Layout sizes the tab view.
-        let tabs = NSTabView(frame: NSRect(x: 0, y: 0, width: 520, height: 520))
+        let tabs = NSTabView(frame: NSRect(x: 0, y: 0, width: 640, height: 620))
         tabs.translatesAutoresizingMaskIntoConstraints = false
         tabs.addTabViewItem(makeOptionsTab(title: "General", views: [
-            makeCharacterSizeSection(),
-            makeScanLinesSection(),
-            makeNumericSection(title: "Frame rate", field: frameRateField, description: MatrixScreenSaverOptions.frameRateDescription),
+            makeDescriptionLabel("Shared settings for the screen saver and animated wallpaper."),
+            makeOptionsGroup(title: "Rendering", views: [
+                makeCharacterSizeSection(),
+                makeNumericSection(title: "Frame rate", field: frameRateField, description: "Frames per second. Higher values use more energy."),
+            ]),
+            makeOptionsGroup(title: "Shared effects", views: [
+                makeScanLinesSection(),
+                makeCheckboxSection(checkbox: twinkleCheckbox, description: "Vary character brightness in the rain and trace program."),
+            ]),
         ]))
         tabs.addTabViewItem(makeOptionsTab(title: "Intro scenes", views: [
-            makeSceneGroup(views: [
-                makeCheckboxSection(checkbox: neoMessageSceneCheckbox, description: MatrixScreenSaverOptions.neoMessageSceneDescription),
-                makeTextSection(title: "Name", field: nameField, description: MatrixScreenSaverOptions.nameDescription, fieldWidth: Self.textFieldWidth / 2),
+            makeNumericSection(title: "Typing speed", field: neoMessageSpeedFactorField, description: "Speed multiplier for all intro scenes. 1 is normal speed."),
+            makeOptionsGroup(title: "1. Neo message", views: [
+                neoMessageSceneCheckbox,
+                makeTextSection(title: "Name", field: nameField, description: "Used in “Wake up, {name}…”. Leave empty for Neo."),
                 makeNeoMessageLinesButtonRow(),
             ]),
-            makeSceneGroup(views: [makeCustomShellCommandsSection()]),
-            makeSceneGroup(views: [makeCheckboxSection(checkbox: numberSceneCheckbox, description: MatrixScreenSaverOptions.numberSceneDescription)]),
-            makeNumericSection(title: "Typing speed", field: neoMessageSpeedFactorField, description: MatrixScreenSaverOptions.neoMessageSpeedFactorDescription),
+            makeOptionsGroup(title: "2. Custom commands", views: [makeCustomShellCommandsSection()]),
+            makeOptionsGroup(title: "3. Trace program", views: [numberSceneCheckbox]),
         ]))
         tabs.addTabViewItem(makeOptionsTab(title: "Rain", views: [
-             makeCheckboxSection(checkbox: twinkleCheckbox, description: MatrixScreenSaverOptions.twinkleDescription),
-             makeCheckboxSection(checkbox: diffuseCheckbox, description: MatrixScreenSaverOptions.diffuseDescription),
-             makeNumericSection(title: "Density", field: rainDensityField, description: MatrixScreenSaverOptions.rainDensityDescription),
-              makeRainDurationSection(),
-              makeRainGlyphSection(),
-              makeRainFontsSection(),
-             makeTextSection(title: "Characters", field: charactersField, description: MatrixScreenSaverOptions.charactersDescription, fieldWidth: Self.textFieldWidth / 2),
-             makeNumericSection(title: "Error rate", field: errorRateField, description: MatrixScreenSaverOptions.errorRateDescription),
+            makeDescriptionLabel("The falling characters shown after the intro scenes."),
+            makeOptionsGroup(title: "Characters", views: [
+                makeRainGlyphSection(),
+                makeRainFontsSection(),
+                makeTextSection(title: "Custom glyphs", field: charactersField, description: "Leave empty to use the selected font’s character set."),
+            ]),
+            makeOptionsGroup(title: "Animation", views: [
+                makeNumericSection(title: "Density", field: rainDensityField, description: "Number of falling streams. 1 is normal density."),
+                makeRainDurationSection(),
+                makeNumericSection(title: "Change rate", field: errorRateField, description: "How often characters change. 0 keeps each character fixed."),
+            ]),
+            makeOptionsGroup(title: "Effects", views: [
+                makeCheckboxSection(checkbox: diffuseCheckbox, description: "Add a soft glow around falling characters."),
+            ]),
         ]))
-        rootStack.addArrangedSubview(tabs)
+        optionsScrollView.borderType = .noBorder
+        optionsScrollView.drawsBackground = false
+        optionsScrollView.hasVerticalScroller = true
+        optionsScrollView.autohidesScrollers = true
+        optionsScrollView.scrollerStyle = .overlay
+        optionsScrollView.documentView = tabs
+        rootStack.addArrangedSubview(optionsScrollView)
+        optionsHeight = optionsScrollView.heightAnchor.constraint(equalToConstant: 620)
+        optionsHeight?.isActive = true
 
         let groupWidth = -(rootStack.edgeInsets.left + rootStack.edgeInsets.right)
-        // Keep every page the same size so switching tabs never moves the dialog buttons.
+        // Reserve space for the longest page so every setting stays visible when switching tabs.
         NSLayoutConstraint.activate([
-            tabs.widthAnchor.constraint(equalToConstant: 520),
-            tabs.heightAnchor.constraint(equalToConstant: 550),
-            tabs.widthAnchor.constraint(equalTo: rootStack.widthAnchor, constant: groupWidth),
+            tabs.widthAnchor.constraint(equalToConstant: 640),
+            tabs.heightAnchor.constraint(equalToConstant: 620),
+            optionsScrollView.widthAnchor.constraint(equalTo: rootStack.widthAnchor, constant: groupWidth),
+            optionsScrollView.widthAnchor.constraint(equalToConstant: 640),
         ])
 
         let buttons = NSStackView()
@@ -638,11 +717,16 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         buttons.alignment = .centerY
         buttons.translatesAutoresizingMaskIntoConstraints = false
 
-        let resetButton = NSButton(title: "Reset to defaults", target: self, action: #selector(resetToDefaults(_:)))
+        let resetButton = NSButton(title: "Restore Defaults", target: self, action: #selector(resetToDefaults(_:)))
         let cancelButton = NSButton(title: "Cancel", target: self, action: #selector(cancel(_:)))
-        let okButton = NSButton(title: "OK", target: self, action: #selector(apply(_:)))
+        let okButton = NSButton(title: "Save", target: self, action: #selector(apply(_:)))
         okButton.keyEquivalent = "\r"
         cancelButton.keyEquivalent = "\u{1b}"
+        okButton.bezelStyle = .rounded
+        cancelButton.bezelStyle = .rounded
+        resetButton.bezelStyle = .rounded
+        okButton.widthAnchor.constraint(greaterThanOrEqualToConstant: 72).isActive = true
+        cancelButton.widthAnchor.constraint(greaterThanOrEqualToConstant: 72).isActive = true
         buttons.addArrangedSubview(cancelButton)
         buttons.addArrangedSubview(okButton)
 
@@ -657,16 +741,23 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
             .infoDictionary?["CFBundleShortVersionString"] as? String ?? ""
         let versionLabel = NSTextField(labelWithString: versionString.isEmpty ? "" : "v\(versionString)")
         versionLabel.font = .systemFont(ofSize: 11)
-        versionLabel.textColor = .tertiaryLabelColor
+        versionLabel.textColor = .secondaryLabelColor
         versionLabel.setContentHuggingPriority(.required, for: .horizontal)
 
-        let coffeeButton = NSButton(title: "Buy me a coffee ☕", target: self, action: #selector(openDonationPage(_:)))
+        let coffeeButton = NSButton(title: "Buy Me a Coffee", target: self, action: #selector(openDonationPage(_:)))
+        // Source: https://cdn.buymeacoffee.com/assets/homepage/meta/favicon-32x32.png
+        coffeeButton.image = Bundle(for: MatrixScreenSaverOptionsSheetController.self).image(forResource: "BuyMeACoffee")
+        coffeeButton.image?.size = NSSize(width: 16, height: 16)
+        coffeeButton.image?.isTemplate = false
+        coffeeButton.imagePosition = .imageLeft
         coffeeButton.bezelStyle = .inline
         coffeeButton.isBordered = false
         coffeeButton.controlSize = .small
         coffeeButton.contentTintColor = .linkColor
         coffeeButton.font = aboutButton.font
         coffeeButton.setContentHuggingPriority(.required, for: .horizontal)
+        // The native centered title uses half the extra width as icon-to-label spacing.
+        coffeeButton.widthAnchor.constraint(greaterThanOrEqualToConstant: coffeeButton.intrinsicContentSize.width + 8).isActive = true
 
         let spacerRight = NSView()
         spacerRight.translatesAutoresizingMaskIntoConstraints = false
@@ -674,12 +765,22 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         spacerRight.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
 
         footer.addArrangedSubview(resetButton)
-        footer.addArrangedSubview(aboutButton)
-        footer.addArrangedSubview(versionLabel)
-        footer.addArrangedSubview(coffeeButton)
         footer.addArrangedSubview(spacerRight)
         footer.addArrangedSubview(buttons)
 
+        let informationSpacer = NSView()
+        informationSpacer.setContentHuggingPriority(.defaultLow, for: .horizontal)
+        let information = NSStackView(views: [aboutButton, versionLabel, informationSpacer, coffeeButton])
+        information.alignment = .centerY
+        information.spacing = 8
+        rootStack.addArrangedSubview(information)
+        information.widthAnchor.constraint(equalTo: tabs.widthAnchor).isActive = true
+        let separator = NSBox()
+        separator.boxType = .separator
+        rootStack.addArrangedSubview(separator)
+        separator.widthAnchor.constraint(equalTo: tabs.widthAnchor).isActive = true
+        rootStack.setCustomSpacing(10, after: information)
+        rootStack.setCustomSpacing(12, after: separator)
         rootStack.addArrangedSubview(footer)
         buttons.setHuggingPriority(.required, for: .horizontal)
         resetButton.setContentHuggingPriority(.required, for: .horizontal)
@@ -700,19 +801,22 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         sizeWindowToFitContent()
     }
 
-    /// Wraps scene controls in a native, untitled fieldset without changing their actions.
-    private func makeSceneGroup(views: [NSView]) -> NSBox {
+    /// Groups controls by scope, using native borders and a readable section heading.
+    private func makeOptionsGroup(title: String, views: [NSView]) -> NSBox {
         let box = NSBox()
-        box.titlePosition = .noTitle
-        box.contentViewMargins = NSSize(width: 8, height: 8)
+        box.title = title
+        box.titleFont = .systemFont(ofSize: NSFont.systemFontSize, weight: .semibold)
+        box.contentViewMargins = NSSize(width: 12, height: 10)
         let stack = NSStackView(views: views)
         stack.orientation = .vertical
         stack.alignment = .leading
-        stack.spacing = 6
+        stack.spacing = 8
         stack.translatesAutoresizingMaskIntoConstraints = false
         let content = box.contentView!
         content.addSubview(stack)
         NSLayoutConstraint.activate([
+            // A single-checkbox group still needs room for the native box's content margins.
+            box.heightAnchor.constraint(greaterThanOrEqualTo: stack.heightAnchor, constant: box.contentViewMargins.height * 2),
             stack.leadingAnchor.constraint(equalTo: content.leadingAnchor),
             stack.trailingAnchor.constraint(equalTo: content.trailingAnchor),
             stack.topAnchor.constraint(equalTo: content.topAnchor),
@@ -745,7 +849,7 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         commandsEditButton.action = #selector(editCommands(_:))
         commandsEditButton.setAccessibilityLabel("Edit custom shell commands")
         let label = NSTextField(labelWithString: "Commands")
-        label.font = .systemFont(ofSize: 13, weight: .semibold)
+        label.font = .systemFont(ofSize: NSFont.systemFontSize)
         label.widthAnchor.constraint(equalToConstant: 100).isActive = true
         let heading = NSStackView(views: [label, commandsEditButton])
         heading.spacing = 12
@@ -758,15 +862,15 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         modes.alignment = .leading
         modes.spacing = 4
         let stack = NSStackView(views: [
-            makeCheckboxSection(checkbox: cmdSceneCheckbox, description: MatrixScreenSaverOptions.cmdSceneDescription),
+            cmdSceneCheckbox,
             heading, modes,
             makeNumericSection(title: "Output hold", field: cmdOutputHoldSecondsField,
-                               description: MatrixScreenSaverOptions.cmdOutputHoldSecondsDescription),
+                description: "Seconds to show output after each command finishes. 0 continues immediately."),
         ])
         cmdOutputHoldSecondsField.setAccessibilityLabel("Command output hold in seconds")
         stack.orientation = .vertical
         stack.alignment = .leading
-        stack.spacing = 4
+        stack.spacing = 6
         return stack
     }
 
@@ -797,19 +901,20 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         row.alignment = .centerY
 
         let label = NSTextField(labelWithString: "Lines")
-        label.font = .systemFont(ofSize: 13, weight: .semibold)
+        label.font = .systemFont(ofSize: NSFont.systemFontSize)
         label.setContentHuggingPriority(.required, for: .horizontal)
         label.widthAnchor.constraint(equalToConstant: 100).isActive = true
 
         linesEditButton.target = self
         linesEditButton.action = #selector(editLines(_:))
         linesEditButton.setContentHuggingPriority(.required, for: .horizontal)
+        linesEditButton.setAccessibilityLabel("Edit Neo message lines")
 
         row.addArrangedSubview(label)
         row.addArrangedSubview(linesEditButton)
 
         stack.addArrangedSubview(row)
-        stack.addArrangedSubview(makeDescriptionLabel(MatrixScreenSaverOptions.neoMessageLinesDescription))
+        stack.addArrangedSubview(makeDescriptionLabel("Customize the intro message, or use the default greeting."))
         return stack
     }
 
@@ -1179,7 +1284,7 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         row.alignment = .centerY
 
         let label = NSTextField(labelWithString: "Scan lines")
-        label.font = .systemFont(ofSize: 13, weight: .semibold)
+        label.font = .systemFont(ofSize: NSFont.systemFontSize)
         label.setContentHuggingPriority(.required, for: .horizontal)
         label.widthAnchor.constraint(equalToConstant: 100).isActive = true
         scanLinesSlider.setAccessibilityLabel("Scan line intensity")
@@ -1200,7 +1305,7 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         row.addArrangedSubview(scanLinesDirectionPopup)
 
         stack.addArrangedSubview(row)
-        stack.addArrangedSubview(makeDescriptionLabel(MatrixScreenSaverOptions.scanLinesDescription))
+        stack.addArrangedSubview(makeDescriptionLabel("CRT texture across all scenes. Set to 0% to turn it off."))
         return stack
     }
 
@@ -1236,7 +1341,7 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         row.alignment = .centerY
 
         let label = NSTextField(labelWithString: title)
-        label.font = .systemFont(ofSize: 13, weight: .semibold)
+        label.font = .systemFont(ofSize: NSFont.systemFontSize)
         label.setContentHuggingPriority(.required, for: .horizontal)
         label.widthAnchor.constraint(equalToConstant: 100).isActive = true
         field.setAccessibilityLabel(title)
@@ -1254,9 +1359,10 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         return stack
     }
 
+    /// Keeps the rain-only preset, sample, and customization guidance together.
     private func makeRainGlyphSection() -> NSView {
         let heading = NSTextField(labelWithString: "Glyph set")
-        heading.font = .systemFont(ofSize: 13, weight: .semibold)
+        heading.font = .systemFont(ofSize: NSFont.systemFontSize)
         for (index, radio) in rainGlyphRadios.enumerated() {
             radio.tag = index
             radio.target = self
@@ -1267,15 +1373,19 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         rainGlyphPreview.drawsBackground = true
         rainGlyphPreview.backgroundColor = .black
         rainGlyphPreview.textColor = .green
+        // Fonts can contain thousands of glyphs; the sample must not displace the settings below it.
         rainGlyphPreview.lineBreakMode = .byCharWrapping
-        rainGlyphPreview.maximumNumberOfLines = 0
-        rainGlyphPreview.setAccessibilityLabel("Selected rain glyphs")
-        let stack = NSStackView(views: [heading, row, rainGlyphPreview])
+        rainGlyphPreview.maximumNumberOfLines = 3
+        rainGlyphPreview.heightAnchor.constraint(equalToConstant: 48).isActive = true
+        rainGlyphPreview.setAccessibilityLabel("Rain glyph sample")
+        let note = makeDescriptionLabel("Classic and Resurrections include their own font and glyphs. Choose Default to customize them below.")
+        let stack = NSStackView(views: [heading, row, rainGlyphPreview, note])
         stack.orientation = .vertical
         stack.alignment = .leading
-        stack.spacing = 4
+        stack.spacing = 8
         stack.setHuggingPriority(.required, for: .vertical)
         rainGlyphPreview.widthAnchor.constraint(equalTo: stack.widthAnchor).isActive = true
+        note.widthAnchor.constraint(equalTo: stack.widthAnchor).isActive = true
         row.toolTip = "Classic and Resurrections use their original bundled fonts. Default uses the settings below."
         return stack
     }
@@ -1321,11 +1431,12 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         stack.setHuggingPriority(.required, for: .vertical)
 
         let heading = NSTextField(labelWithString: "Font")
-        heading.font = .systemFont(ofSize: 13, weight: .semibold)
+        heading.font = .systemFont(ofSize: NSFont.systemFontSize)
+        heading.widthAnchor.constraint(equalToConstant: 100).isActive = true
 
         rainFontsButton.setAccessibilityLabel("Font")
         rainFontsButton.translatesAutoresizingMaskIntoConstraints = false
-        rainFontsButton.widthAnchor.constraint(equalToConstant: Self.textFieldWidth).isActive = true
+        rainFontsButton.widthAnchor.constraint(equalToConstant: 220).isActive = true
         (rainFontsButton.cell as? NSPopUpButtonCell)?.lineBreakMode = .byTruncatingTail
 
         let resetButton = rainFontsResetButton
@@ -1336,15 +1447,12 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         resetButton.font = .systemFont(ofSize: NSFont.smallSystemFontSize)
         resetButton.setAccessibilityLabel("Reset font to system default")
         resetButton.toolTip = "Use the default system font"
-        let row = NSStackView(views: [rainFontsButton, resetButton])
+        let row = NSStackView(views: [heading, rainFontsButton, resetButton])
         row.orientation = .horizontal
         row.alignment = .centerY
-        row.spacing = 8
+        row.spacing = 12
 
-        stack.addArrangedSubview(heading)
-        stack.addArrangedSubview(makeDescriptionLabel(MatrixScreenSaverOptions.rainFontsDescription))
         stack.addArrangedSubview(row)
-        stack.setCustomSpacing(8, after: stack.arrangedSubviews[1])
         return stack
     }
 
@@ -1395,7 +1503,7 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
     }
 
     /// Builds a labeled text input row with its description.
-    private func makeTextSection(title: String, field: NSTextField, description: String, fieldWidth: CGFloat? = nil) -> NSView {
+    private func makeTextSection(title: String, field: NSTextField, description: String) -> NSView {
         let stack = NSStackView()
         stack.orientation = .vertical
         stack.alignment = .leading
@@ -1408,7 +1516,7 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         row.alignment = .centerY
 
         let label = NSTextField(labelWithString: title)
-        label.font = .systemFont(ofSize: 13, weight: .semibold)
+        label.font = .systemFont(ofSize: NSFont.systemFontSize)
         label.setContentHuggingPriority(.required, for: .horizontal)
         label.widthAnchor.constraint(equalToConstant: 100).isActive = true
         field.setAccessibilityLabel(title)
@@ -1416,7 +1524,7 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         field.alignment = .left
         field.controlSize = .regular
         field.translatesAutoresizingMaskIntoConstraints = false
-        field.widthAnchor.constraint(equalToConstant: fieldWidth ?? Self.textFieldWidth).isActive = true
+        field.widthAnchor.constraint(equalToConstant: Self.textFieldWidth).isActive = true
 
         row.addArrangedSubview(label)
         row.addArrangedSubview(field)
@@ -1447,7 +1555,7 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
          secondsRow.alignment = .centerY
 
          let secondsLabel = NSTextField(labelWithString: "Seconds")
-         secondsLabel.font = .systemFont(ofSize: 13, weight: .semibold)
+        secondsLabel.font = .systemFont(ofSize: NSFont.systemFontSize)
          secondsLabel.setContentHuggingPriority(.required, for: .horizontal)
          secondsLabel.widthAnchor.constraint(equalToConstant: 100).isActive = true
          rainDurationField.setAccessibilityLabel("Rain duration in seconds")
@@ -1462,7 +1570,7 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
 
          stack.addArrangedSubview(checkboxRow)
          stack.addArrangedSubview(secondsRow)
-         stack.addArrangedSubview(makeDescriptionLabel(MatrixScreenSaverOptions.rainDurationSecondsDescription))
+        stack.addArrangedSubview(makeDescriptionLabel("When off, rain winds down after this many seconds, then the scene sequence repeats."))
          return stack
     }
 
@@ -1480,7 +1588,7 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         row.alignment = .centerY
 
         let titleLabel = NSTextField(labelWithString: "Character size")
-        titleLabel.font = .systemFont(ofSize: 13, weight: .semibold)
+        titleLabel.font = .systemFont(ofSize: NSFont.systemFontSize)
         titleLabel.setContentHuggingPriority(.required, for: .horizontal)
         titleLabel.widthAnchor.constraint(equalToConstant: 100).isActive = true
         characterSizeSlider.setAccessibilityLabel("Character size")
@@ -1497,7 +1605,7 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         row.addArrangedSubview(characterSizeValueLabel)
 
         stack.addArrangedSubview(row)
-        stack.addArrangedSubview(makeDescriptionLabel(MatrixScreenSaverOptions.characterSizeDescription))
+        stack.addArrangedSubview(makeDescriptionLabel("Character cell dimensions in pixels, used by every scene."))
         return stack
     }
 
@@ -1518,21 +1626,9 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         item.label = title
         // Start at the real page size so NSTabView never lays the page out at its 20pt placeholder width,
         // which made the fixed-width rows report unsatisfiable constraints in the screen saver host.
-        let frame = NSRect(x: 0, y: 0, width: 520, height: 550)
-        let scrolls = title == "Rain"
-        let contentView = scrolls ? RainOptionsDocumentView(frame: frame) : NSView(frame: frame)
-        if scrolls {
-            let scrollView = NSScrollView(frame: frame)
-            scrollView.hasVerticalScroller = true
-            scrollView.autohidesScrollers = true
-            scrollView.drawsBackground = false
-            scrollView.documentView = contentView
-            contentView.translatesAutoresizingMaskIntoConstraints = false
-            contentView.widthAnchor.constraint(equalTo: scrollView.contentView.widthAnchor).isActive = true
-            item.view = scrollView
-        } else {
-            item.view = contentView
-        }
+        let frame = NSRect(x: 0, y: 0, width: 640, height: 620)
+        let contentView = NSView(frame: frame)
+        item.view = contentView
         let stack = NSStackView(views: views)
         stack.orientation = .vertical
         stack.alignment = .leading
@@ -1545,8 +1641,7 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
             stack.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 16),
             stack.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -16),
             stack.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 16),
-            scrolls ? stack.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: -16)
-                : stack.bottomAnchor.constraint(lessThanOrEqualTo: contentView.bottomAnchor, constant: -16),
+            stack.bottomAnchor.constraint(lessThanOrEqualTo: contentView.bottomAnchor, constant: -16),
         ])
         for view in views {
             view.widthAnchor.constraint(equalTo: stack.widthAnchor).isActive = true
@@ -1558,7 +1653,7 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
     /// Creates the smaller descriptive text used under each option row.
     private func makeDescriptionLabel(_ description: String) -> NSTextField {
         let label = NSTextField(wrappingLabelWithString: description)
-        label.font = .systemFont(ofSize: 11)
+        label.font = .systemFont(ofSize: NSFont.smallSystemFontSize)
         label.textColor = .secondaryLabelColor
         label.alignment = .left
         label.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
@@ -1712,20 +1807,30 @@ final class MatrixScreenSaverOptionsSheetController: NSObject,
         value.trimmingCharacters(in: .whitespacesAndNewlines)
     }
 
-    /// Resizes the sheet window so it fits the current stack view content.
+    /// Fits the fixed-size pages and action area without making the window user-resizable.
     private func sizeWindowToFitContent() {
         guard let contentView = window.contentView else {
             return
         }
 
+        contentView.layoutSubtreeIfNeeded()
+        // Keep the warning and Save/Cancel on screen; only the fixed-size tab document scrolls.
+        let currentHeight = optionsHeight?.constant ?? 620
+        let chromeHeight = window.frame.height - window.contentRect(forFrameRect: window.frame).height
+        let availableHeight = (window.screen ?? NSScreen.main)?.visibleFrame.height ?? 1000
+        let otherHeight = rootStack.fittingSize.height - currentHeight
+        optionsHeight?.constant = min(620, max(120, availableHeight - chromeHeight - otherHeight - 24))
         contentView.layoutSubtreeIfNeeded()
         let fittingSize = rootStack.fittingSize
         let contentSize = NSSize(
             width: ceil(fittingSize.width),
             height: ceil(fittingSize.height)
         )
-        window.setContentSize(contentSize)
         window.contentMinSize = contentSize
+        window.setContentSize(contentSize)
+        if optionsHeight?.constant != currentHeight, let document = optionsScrollView.documentView {
+            document.scroll(NSPoint(x: 0, y: max(0, document.frame.height - optionsScrollView.contentSize.height)))
+        }
     }
 
     private static let fourDigitFieldWidth: CGFloat = {
diff --git a/Sources/MatrixScreenSaver/MatrixScreenSaverView.swift b/Sources/MatrixScreenSaver/MatrixScreenSaverView.swift
index c938184..b88cf2e 100644
--- a/Sources/MatrixScreenSaver/MatrixScreenSaverView.swift
+++ b/Sources/MatrixScreenSaver/MatrixScreenSaverView.swift
@@ -42,6 +42,14 @@ final class MatrixScreenSaverView: ScreenSaverView {
     /// Set before starting animation; ordinary saver and preview hosts keep the default.
     var isWallpaperHost = false
 
+    /// Wallpaper supplies its host snapshot; the saver checks its own loaded bundle.
+    var readVersionStatus: () -> MatrixVersionStatus = {
+        MatrixVersionStatus.current(hostBundle: Bundle(for: MatrixScreenSaverView.self))
+    }
+    private var versionMismatch = false
+    private var nextVersionCheck: TimeInterval = 0
+    private var errorMotionTime: TimeInterval = 0
+
     /// Lets the wallpaper's sole animation session continue while a saver covers its windows.
     var rendersWallpaperWhileHidden = false
 
@@ -245,6 +253,17 @@ final class MatrixScreenSaverView: ScreenSaverView {
         super.startAnimation()
         animationActive = true
         firstHiddenFrameTime = 0
+        versionMismatch = readVersionStatus().state == .mismatch
+        nextVersionCheck = ProcessInfo.processInfo.systemUptime + 60
+        updateScreenSaverLifecycleObservation()
+        if versionMismatch {
+            nativeRenderer.stop()
+            animationTimeInterval = 1.0 / 30.0
+            setAccessibilityLabel("Version mismatch. Install matching versions to play.")
+            needsDisplay = true
+            return
+        }
+        setAccessibilityLabel(nil)
         if shouldReloadOptionsOnStart {
             saverOptions = Self.loadSaverOptions()
         }
@@ -252,7 +271,6 @@ final class MatrixScreenSaverView: ScreenSaverView {
         wallpaperFrameReader = !isWallpaperHost && !isPreview && Self.isRunningInScreenSaverEngine ? WallpaperFrameReader() : nil
         NSLog("MatrixScreenSaver startAnimation bounds=%@", NSStringFromRect(bounds))
         appendDebugLog("[\(debugIdentifier)] startAnimation bounds=\(NSStringFromRect(bounds))")
-        updateScreenSaverLifecycleObservation()
         if let wallpaperFrameReader {
             nativeRenderer.stop()
             awaitingWallpaperUntil = ProcessInfo.processInfo.systemUptime + 1
@@ -328,6 +346,13 @@ final class MatrixScreenSaverView: ScreenSaverView {
         }
         firstHiddenFrameTime = 0
 
+        if ProcessInfo.processInfo.systemUptime >= nextVersionCheck { refreshVersionStatus() }
+        if versionMismatch {
+            if !NSWorkspace.shared.accessibilityDisplayShouldReduceMotion { errorMotionTime += animationTimeInterval }
+            needsDisplay = true
+            return
+        }
+
         if let wallpaperFrameReader {
             if let frame = wallpaperFrameReader.frame(displayID: UInt32(displaySeed), pointSize: bounds.size) {
                 awaitingWallpaperUntil = nil
@@ -437,6 +462,17 @@ final class MatrixScreenSaverView: ScreenSaverView {
 
     /// Paints the full terminal-window scene for the current frame.
     override func draw(_ dirtyRect: NSRect) {
+        if versionMismatch {
+            NSColor.black.setFill()
+            bounds.fill()
+            let size = min(72, min(bounds.width, bounds.height) * 0.2)
+            let reduced = NSWorkspace.shared.accessibilityDisplayShouldReduceMotion
+            let x = reduced ? 0 : sin(errorMotionTime * 0.12) * max(0, bounds.width - size) * 0.4
+            let y = reduced ? 0 : sin(errorMotionTime * 0.09) * max(0, bounds.height - size) * 0.4
+            MatrixVersionStatus.warningImage?.draw(in: NSRect(x: bounds.midX + x - size / 2,
+                                                          y: bounds.midY + y - size / 2, width: size, height: size))
+            return
+        }
         if let image = sharedWallpaperImage ?? publishedWallpaperImage {
             NSGraphicsContext.current?.cgContext.draw(image, in: bounds)
             return
@@ -1259,7 +1295,7 @@ final class MatrixScreenSaverView: ScreenSaverView {
     ///
     /// - Returns: A private shared-memory file, or nil if this host cannot publish it.
     func shareWallpaperFrames() -> URL? {
-        guard isWallpaperHost, animationActive else { return nil }
+        guard isWallpaperHost, animationActive, !versionMismatch else { return nil }
         let scale = window?.backingScaleFactor ?? 1
         if sharedFrameBuffer?.pointSize != bounds.size || sharedFrameBuffer?.displayID != UInt32(displaySeed) ||
             sharedFrameBuffer?.pixelWidth != Int(ceil(bounds.width * scale)) ||
@@ -1418,6 +1454,21 @@ final class MatrixScreenSaverView: ScreenSaverView {
         super.startAnimation()
     }
 
+    /// Stops incompatible rendering and frame sharing, or restarts after versions match.
+    func refreshVersionStatus() {
+        nextVersionCheck = ProcessInfo.processInfo.systemUptime + 60
+        let mismatch = readVersionStatus().state == .mismatch
+        guard mismatch != versionMismatch else { return }
+        versionMismatch = mismatch
+        if animationActive {
+            let wasPaused = wallpaperAnimationPaused
+            stopAnimation()
+            startAnimation()
+            if wasPaused { pauseWallpaperAnimation() }
+        }
+        needsDisplay = true
+    }
+
     /// Applies options to the live saver and optionally persists or restarts it.
     private func applySaverOptions(_ options: MatrixScreenSaverOptions, persist: Bool, restartAnimation: Bool) {
         let sanitizedOptions = options.sanitized()
@@ -1454,7 +1505,7 @@ final class MatrixScreenSaverView: ScreenSaverView {
 
     /// Creates a fresh configure-sheet controller for each presentation.
     private func makeOptionsSheetController() -> MatrixScreenSaverOptionsSheetController {
-        let controller = MatrixScreenSaverOptionsSheetController { [weak self] options in
+        let controller = MatrixScreenSaverOptionsSheetController(readVersionStatus: readVersionStatus) { [weak self] options in
             self?.applySaverOptionsFromSheet(options)
         }
         controller.onClose = { [weak self, weak controller] in
diff --git a/Sources/MatrixScreenSaver/MatrixVersionStatus.swift b/Sources/MatrixScreenSaver/MatrixVersionStatus.swift
new file mode 100644
index 0000000..00c13d7
--- /dev/null
+++ b/Sources/MatrixScreenSaver/MatrixVersionStatus.swift
@@ -0,0 +1,159 @@
+import AppKit
+
+/// Compares the loaded component with discoverable companion installations, not another process's memory.
+struct MatrixVersionStatus: Equatable {
+    /// Missing and unreadable metadata must not be presented as proven compatibility.
+    enum State {
+        case matching, mismatch, missingCompanion, unverified
+    }
+
+    /// Identifies a copy without assuming macOS has selected it as the active screen saver.
+    struct Installation: Equatable {
+        /// Canonical bundle location, also used to collapse symlinks.
+        let url: URL
+        /// Release version; nil means the bundle is recognized but its version is unavailable.
+        let version: String?
+        /// Distinguishes this process's metadata from metadata read off disk.
+        let isLoaded: Bool
+    }
+
+    /// Wallpaper copies relevant to this host.
+    let wallpapers: [Installation]
+    /// Loaded and installed screen-saver copies, deduplicated by canonical path.
+    let screenSavers: [Installation]
+    /// Records a failed discovery read, so an inaccessible directory is not treated as empty.
+    let discoveryIncomplete: Bool
+
+    /// Standard user and machine-wide screen-saver installation directories.
+    static var screenSaverDirectories: [URL] {
+        FileManager.default.urls(for: .libraryDirectory, in: [.userDomainMask, .localDomainMask])
+            .map { $0.appendingPathComponent("Screen Savers") }
+    }
+
+    /// Recovery destination shared by both native hosts.
+    static let releasesURL = URL(string: "https://github.com/patrickschaper/matrixScreenSaver/releases")!
+
+    /// Standard macOS warning triangle shared by dialogs, menus, and blocked playback.
+    static let warningImage = NSImage(named: NSImage.cautionName)
+
+    /// A confirmed differing pair takes precedence over other unreadable copies.
+    var state: State {
+        let wallpaperVersions = wallpapers.compactMap(\.version)
+        let saverVersions = screenSavers.compactMap(\.version)
+        if !wallpaperVersions.isEmpty && !saverVersions.isEmpty && Set(wallpaperVersions + saverVersions).count > 1 {
+            return .mismatch
+        }
+        if discoveryIncomplete || (wallpapers + screenSavers).contains(where: { $0.version == nil }) {
+            return .unverified
+        }
+        return wallpapers.isEmpty || screenSavers.isEmpty ? .missingCompanion : .matching
+    }
+
+    /// Shared heading for persistent warnings and the launch alert.
+    var title: String {
+        state == .mismatch ? "Version Mismatch" : "Version Unavailable"
+    }
+
+    /// Compact version information suitable for the menu and options banner.
+    var versionSummary: String {
+        "Wallpaper \(Self.versions(wallpapers)) · Screen Saver \(Self.versions(screenSavers))"
+    }
+
+    /// Gives the shortest recovery instruction for the current status.
+    var explanation: String {
+        if state == .mismatch {
+            return "Install matching versions to play."
+        }
+        return "Couldn’t check versions."
+    }
+
+    /// Keeps native dialogs to version numbers and one recovery sentence.
+    var message: String {
+        "\(versionSummary)\n\(explanation)"
+    }
+
+    /// Reads disk metadata afresh while preserving the hosting bundle's loaded version.
+    ///
+    /// - Parameters:
+    ///   - hostBundle: The bundle containing Matrix code, never System Settings or ScreenSaverEngine.
+    ///   - screenSaverDirectories: Bounded installation directories; replace with isolated fixtures in tests.
+    ///   - wallpaperURLs: Explicit candidates, or nil to use macOS discovery and standard app locations.
+    /// - Returns: A snapshot; inaccessible reads remain unverified rather than implying a match.
+    static func current(hostBundle: Bundle, screenSaverDirectories: [URL] = screenSaverDirectories,
+                        wallpaperURLs: [URL]? = nil) -> MatrixVersionStatus {
+        let saverID = "dev.patsch.MatrixScreenSaver"
+        let wallpaperID = "dev.patsch.MatrixWallpaper"
+        var incomplete = false
+        var savers: [Installation] = []
+        var wallpapers: [Installation] = []
+
+        func read(_ url: URL, identifier: String) -> Installation? {
+            do {
+                let data = try Data(contentsOf: url.appendingPathComponent("Contents/Info.plist"))
+                guard let metadata = try PropertyListSerialization.propertyList(from: data, format: nil) as? [String: Any],
+                      metadata["CFBundleIdentifier"] as? String == identifier else { return nil }
+                return Installation(url: url.resolvingSymlinksInPath().standardizedFileURL,
+                                    version: version(in: metadata), isLoaded: false)
+            } catch {
+                if !isMissing(error) { incomplete = true }
+                return nil
+            }
+        }
+
+        for directory in screenSaverDirectories {
+            do {
+                let urls = try FileManager.default.contentsOfDirectory(at: directory, includingPropertiesForKeys: nil)
+                savers += urls.filter { $0.pathExtension.lowercased() == "saver" }.compactMap { read($0, identifier: saverID) }
+            } catch {
+                if !isMissing(error) { incomplete = true }
+            }
+        }
+
+        let hostID = hostBundle.bundleIdentifier
+        if hostID == wallpaperID || hostID == saverID {
+            let loaded = Installation(url: hostBundle.bundleURL.resolvingSymlinksInPath().standardizedFileURL,
+                                      version: version(in: hostBundle.infoDictionary ?? [:]), isLoaded: true)
+            if hostID == wallpaperID {
+                wallpapers = [loaded]
+            } else {
+                savers.removeAll { $0.url == loaded.url }
+                savers.append(loaded)
+                let candidates = wallpaperURLs ?? wallpaperCandidates(identifier: wallpaperID)
+                wallpapers = candidates.compactMap { read($0, identifier: wallpaperID) }
+            }
+        }
+        return MatrixVersionStatus(wallpapers: unique(wallpapers), screenSavers: unique(savers), discoveryIncomplete: incomplete)
+    }
+
+    private static func version(in metadata: [String: Any]) -> String? {
+        guard let value = (metadata["CFBundleShortVersionString"] as? String)?.trimmingCharacters(in: .whitespacesAndNewlines),
+              !value.isEmpty else { return nil }
+        return value
+    }
+
+    private static func versions(_ installations: [Installation]) -> String {
+        guard !installations.isEmpty else { return "Not found" }
+        return Set(installations.map { $0.version ?? "Version unavailable" }).sorted().joined(separator: ", ")
+    }
+
+    private static func unique(_ installations: [Installation]) -> [Installation] {
+        var seen = Set<URL>()
+        return installations.filter { seen.insert($0.url).inserted }.sorted { $0.url.path < $1.url.path }
+    }
+
+    private static func isMissing(_ error: Error) -> Bool {
+        let error = error as NSError
+        return error.domain == NSCocoaErrorDomain && [NSFileNoSuchFileError, NSFileReadNoSuchFileError].contains(error.code)
+    }
+
+    private static func wallpaperCandidates(identifier: String) -> [URL] {
+        var urls = NSRunningApplication.runningApplications(withBundleIdentifier: identifier).compactMap(\.bundleURL)
+        urls += NSWorkspace.shared.urlsForApplications(withBundleIdentifier: identifier)
+        for directory in FileManager.default.urls(for: .applicationDirectory, in: [.userDomainMask, .localDomainMask]) {
+            for name in ["Matrix Wallpaper.app", "MatrixWallpaper.app"] {
+                urls.append(directory.appendingPathComponent(name))
+            }
+        }
+        return urls
+    }
+}
diff --git a/Sources/MatrixWallpaper/WallpaperApp.swift b/Sources/MatrixWallpaper/WallpaperApp.swift
index 079d4d6..7a15d08 100644
--- a/Sources/MatrixWallpaper/WallpaperApp.swift
+++ b/Sources/MatrixWallpaper/WallpaperApp.swift
@@ -16,8 +16,17 @@ final class WallpaperApp: NSObject, NSApplicationDelegate, NSMenuDelegate {
 
     /// Wallpaper-only preferences, separate from shared rendering options.
     private let defaults: UserDefaults
-    /// Installed saver locations, replaceable with temporary directories in tests.
-    private let screenSaverDirectories: [URL]
+    /// Shared discovery also drives synchronization availability without a second directory scan.
+    private let readVersionStatus: () -> MatrixVersionStatus
+    /// Keeps the modal side effect replaceable in native host tests.
+    private let presentVersionAlert: (NSAlert) -> NSApplication.ModalResponse
+    private var versionStatus: MatrixVersionStatus?
+    private var versionRefreshTimer: Timer?
+    private var versionAlert: NSAlert?
+    private var normalStatusImage: NSImage?
+    private var warningStatusImage: NSImage?
+    private let versionWarningItem = NSMenuItem(title: "Version Mismatch…", action: #selector(showVersionWarning(_:)), keyEquivalent: "")
+    private let versionSeparator = NSMenuItem.separator()
     /// Persists user intent even while no saver is installed.
     private static let syncPreferenceKey = "syncWithScreenSaver"
     /// Reflects whether the wallpaper may serve frames to the saver.
@@ -30,13 +39,19 @@ final class WallpaperApp: NSObject, NSApplicationDelegate, NSMenuDelegate {
     ///   - defaults: Store for wallpaper-only preferences.
     ///   - screenSaverDirectories: User and local installed-saver directories.
     ///   - desktopWallpaper: Durable desktop settings controller, isolated in tests.
+    ///   - readVersionStatus: Optional isolated discovery, shared with the options sheet.
+    ///   - presentVersionAlert: Presents the native alert and returns the chosen action.
     init(loginItems: LoginItemController = LoginItemController(), defaults: UserDefaults = .standard,
-         screenSaverDirectories: [URL] = FileManager.default.urls(for: .libraryDirectory, in: [.userDomainMask, .localDomainMask])
-            .map { $0.appendingPathComponent("Screen Savers") },
-         desktopWallpaper: DesktopWallpaperController = DesktopWallpaperController()) {
+         screenSaverDirectories: [URL] = MatrixVersionStatus.screenSaverDirectories,
+         desktopWallpaper: DesktopWallpaperController = DesktopWallpaperController(),
+         readVersionStatus: (() -> MatrixVersionStatus)? = nil,
+         presentVersionAlert: @escaping (NSAlert) -> NSApplication.ModalResponse = { $0.runModal() }) {
         self.loginItems = loginItems
         self.defaults = defaults
-        self.screenSaverDirectories = screenSaverDirectories
+        self.readVersionStatus = readVersionStatus ?? {
+            MatrixVersionStatus.current(hostBundle: Bundle(for: WallpaperApp.self), screenSaverDirectories: screenSaverDirectories)
+        }
+        self.presentVersionAlert = presentVersionAlert
         self.desktopWallpaper = desktopWallpaper
         super.init()
         defaults.register(defaults: [Self.syncPreferenceKey: true])
@@ -55,10 +70,10 @@ final class WallpaperApp: NSObject, NSApplicationDelegate, NSMenuDelegate {
     private var isTerminating = false
 
     /// Menu action whose label follows requested playback, not temporary suspension.
-    private let playbackButton = NSButton(title: "Stop", target: nil, action: #selector(togglePlayback(_:)))
+    private let playbackItem = NSMenuItem(title: "Stop Wallpaper", action: #selector(togglePlayback(_:)), keyEquivalent: "")
 
     /// Manual pause remains available independently of temporary system suspension.
-    private let pauseButton = NSButton(title: "Pause", target: nil, action: #selector(togglePause(_:)))
+    private let pauseItem = NSMenuItem(title: "Pause Animation", action: #selector(togglePause(_:)), keyEquivalent: "")
 
     /// Retains native options UI independently of transient wallpaper views.
     private var optionsController: MatrixScreenSaverOptionsSheetController?
@@ -102,37 +117,59 @@ final class WallpaperApp: NSObject, NSApplicationDelegate, NSMenuDelegate {
         } else {
             item.button?.title = "M"
         }
-        item.button?.toolTip = "Matrix Wallpaper"
         item.button?.setAccessibilityLabel("Matrix Wallpaper")
+        normalStatusImage = item.button?.image
+        let warningSymbol = NSImage(systemSymbolName: "exclamationmark.triangle.fill", accessibilityDescription: "Version mismatch")
+        if let normalStatusImage, let warningSymbol {
+            warningStatusImage = NSImage(size: NSSize(width: 32, height: 18), flipped: false) { rect in
+                normalStatusImage.draw(in: NSRect(x: 0, y: 0, width: 18, height: 18))
+                warningSymbol.draw(in: NSRect(x: 19, y: 2, width: 13, height: 14))
+                return true
+            }
+            warningStatusImage?.isTemplate = true
+        } else {
+            warningStatusImage = warningSymbol
+            item.button?.imagePosition = .imageRight
+        }
         let menu = NSMenu()
         menu.autoenablesItems = false
         menu.delegate = self
-        for button in [playbackButton, pauseButton] {
-            button.target = self
-            button.bezelStyle = .rounded
+        versionWarningItem.target = self
+        versionWarningItem.image = MatrixVersionStatus.warningImage?.copy() as? NSImage
+        versionWarningItem.image?.size = NSSize(width: 18, height: 18)
+        versionWarningItem.image?.isTemplate = false
+        // macOS 27 hides menu images by default; KVC keeps builds compatible with older SDKs.
+        if versionWarningItem.responds(to: NSSelectorFromString("setPreferredImageVisibility:")) {
+            versionWarningItem.setValue(1, forKey: "preferredImageVisibility") // NSMenuItem.ImageVisibility.visible
+        }
+        for warningItem in [versionWarningItem, versionSeparator] {
+            warningItem.isHidden = true
+            menu.addItem(warningItem)
         }
-        let controls = NSStackView(views: [playbackButton, pauseButton])
-        controls.orientation = .horizontal
-        controls.alignment = .centerY
-        controls.distribution = .fillEqually
-        controls.spacing = 8
-        controls.edgeInsets = NSEdgeInsets(top: 4, left: 14, bottom: 4, right: 14)
-        controls.frame = NSRect(x: 0, y: 0, width: 240, height: 36)
-        controls.autoresizingMask = [.width]
-        let playbackRow = NSMenuItem(title: "Playback", action: nil, keyEquivalent: "")
-        playbackRow.view = controls
-        menu.addItem(playbackRow)
-        let options = NSMenuItem(title: "Options…", action: #selector(showOptions(_:)), keyEquivalent: "")
+        pauseItem.target = self
+        playbackItem.target = self
+        updatePlaybackMenu()
+        menu.addItem(pauseItem)
+        menu.addItem(playbackItem)
+        menu.addItem(.separator())
+        let options = NSMenuItem(title: "Settings…", action: #selector(showOptions(_:)), keyEquivalent: ",")
         options.target = self
         menu.addItem(options)
         syncItem.target = self
-        menu.addItem(.separator())
         menu.addItem(loginItems.item)
         menu.addItem(syncItem)
         menu.addItem(.separator())
-        let coffee = NSMenuItem(title: "Buy me a coffee ☕", action: #selector(openDonationPage(_:)), keyEquivalent: "")
+        let coffee = NSMenuItem(title: "Buy Me a Coffee", action: #selector(openDonationPage(_:)), keyEquivalent: "")
+        coffee.image = Bundle.main.image(forResource: "BuyMeACoffee")
+        coffee.image?.size = NSSize(width: 16, height: 16)
+        coffee.image?.isTemplate = false
+        // macOS 27 hides menu images by default; retain the full-color favicon.
+        if coffee.responds(to: NSSelectorFromString("setPreferredImageVisibility:")) {
+            coffee.setValue(1, forKey: "preferredImageVisibility")
+        }
         coffee.target = self
         menu.addItem(coffee)
+        menu.addItem(.separator())
         let quit = NSMenuItem(title: "Quit Matrix Wallpaper", action: #selector(NSApplication.terminate(_:)), keyEquivalent: "q")
         quit.target = NSApp
         menu.addItem(quit)
@@ -141,6 +178,10 @@ final class WallpaperApp: NSObject, NSApplicationDelegate, NSMenuDelegate {
         menuWillOpen(menu)
 
         observeSystemState()
+        versionRefreshTimer = Timer.scheduledTimer(withTimeInterval: 60, repeats: true) { [weak self] _ in
+            self?.refreshVersionStatus()
+        }
+        versionRefreshTimer?.tolerance = 10
         frameLeaseTimer = Timer.scheduledTimer(withTimeInterval: 0.5, repeats: true) { [weak self] _ in
             guard let self else { return }
             let now = ProcessInfo.processInfo.systemUptime
@@ -166,6 +207,9 @@ final class WallpaperApp: NSObject, NSApplicationDelegate, NSMenuDelegate {
         })
         let startup = DispatchWorkItem { [weak self] in
             guard let self, !self.isTerminating, self.pendingLaunch != nil else { return }
+            self.showVersionWarning(nil)
+            // A modal warning can receive Stop or Quit before desktop recovery starts.
+            guard !self.isTerminating, self.pendingLaunch != nil else { return }
             if self.playback.isRequested { self.updateDesktopWallpaper(restoring: true) }
             // Recovery alerts can pump the run loop and receive Stop or Quit.
             guard !self.isTerminating, self.pendingLaunch != nil else { return }
@@ -196,16 +240,50 @@ final class WallpaperApp: NSObject, NSApplicationDelegate, NSMenuDelegate {
     func menuWillOpen(_ menu: NSMenu) {
         loginItems.menuWillOpen(menu)
         syncItem.state = defaults.bool(forKey: Self.syncPreferenceKey) ? .on : .off
-        syncItem.isHidden = !screenSaverDirectories.contains { directory in
-            let bundles = (try? FileManager.default.contentsOfDirectory(at: directory, includingPropertiesForKeys: nil)) ?? []
-            return bundles.contains { url in
-                guard url.pathExtension.lowercased() == "saver",
-                      let data = try? Data(contentsOf: url.appendingPathComponent("Contents/Info.plist")),
-                      let metadata = try? PropertyListSerialization.propertyList(from: data, options: [], format: nil) as? [String: Any]
-                else { return false }
-                return metadata["CFBundleIdentifier"] as? String == "dev.patsch.MatrixScreenSaver"
+        refreshVersionStatus()
+    }
+
+    /// Refreshes persistent warnings independently of animation and pending option edits.
+    private func refreshVersionStatus() {
+        guard !isTerminating else { return }
+        let status = readVersionStatus()
+        syncItem.isHidden = status.screenSavers.isEmpty
+        if status != versionStatus {
+            let hadStatus = versionStatus != nil
+            let wasMismatch = versionStatus?.state == .mismatch
+            versionStatus = status
+            let mismatch = status.state == .mismatch
+            for item in [versionWarningItem, versionSeparator] {
+                item.isHidden = !mismatch
             }
+            statusItem?.button?.image = mismatch ? warningStatusImage : normalStatusImage
+            statusItem?.button?.setAccessibilityLabel(mismatch ? "Matrix Wallpaper — version mismatch" : "Matrix Wallpaper")
+            if mismatch { endFrameSharing() }
+            if hadStatus { reconcilePlayback(restart: wasMismatch != mismatch) }
         }
+        optionsController?.refreshVersionStatus()
+    }
+
+    /// Automatic presentation occurs only in queued launch; the menu can reopen it explicitly.
+    @objc private func showVersionWarning(_ sender: Any?) {
+        refreshVersionStatus()
+        guard !isTerminating, versionAlert == nil, let status = versionStatus, status.state == .mismatch else { return }
+        let alert = NSAlert()
+        alert.alertStyle = .warning
+        alert.icon = MatrixVersionStatus.warningImage
+        alert.messageText = status.title
+        alert.informativeText = status.message
+        alert.addButton(withTitle: "View Releases…")
+        alert.addButton(withTitle: "Close")
+        versionAlert = alert
+        NSApp.activate(ignoringOtherApps: true)
+        let response = presentVersionAlert(alert)
+        versionAlert = nil
+        if !isTerminating && response == .alertFirstButtonReturn { openReleases(nil) }
+    }
+
+    @objc private func openReleases(_ sender: Any?) {
+        NSWorkspace.shared.open(MatrixVersionStatus.releasesURL)
     }
 
     /// Stores the choice without changing the wallpaper's requested playback state.
@@ -246,7 +324,7 @@ final class WallpaperApp: NSObject, NSApplicationDelegate, NSMenuDelegate {
             NSApp.activate(ignoringOtherApps: true)
             return
         }
-        let controller = MatrixScreenSaverOptionsSheetController { [weak self] options in
+        let controller = MatrixScreenSaverOptionsSheetController(readVersionStatus: readVersionStatus) { [weak self] options in
             self?.applyOptions(options)
         }
         controller.onClose = { [weak self] in self?.optionsController = nil }
@@ -282,9 +360,7 @@ final class WallpaperApp: NSObject, NSApplicationDelegate, NSMenuDelegate {
     /// - Parameter restart: Forces coordinated reconstruction after options or display changes.
     private func reconcilePlayback(restart: Bool = false) {
         guard !isTerminating else { return }
-        playbackButton.title = playback.isRequested ? "Stop" : "Start"
-        pauseButton.title = playback.isPaused ? "Resume" : "Pause"
-        pauseButton.isEnabled = playback.isRequested
+        updatePlaybackMenu()
         guard pendingLaunch == nil else { return }
         if !playback.isRequested { updateDesktopWallpaper(restoring: true) }
         if !playback.isRequested || restart { removeDesktopWindows() }
@@ -306,6 +382,7 @@ final class WallpaperApp: NSObject, NSApplicationDelegate, NSMenuDelegate {
                     return
                 }
                 saver.isWallpaperHost = true
+                saver.readVersionStatus = readVersionStatus
                 saver.rendersWallpaperWhileHidden = playback.isServingScreenSaver
                 let window = DesktopWindow(screen: screen, saverView: saver)
                 windows.append(window)
@@ -339,6 +416,15 @@ final class WallpaperApp: NSObject, NSApplicationDelegate, NSMenuDelegate {
         }
     }
 
+    /// Keeps native command labels, symbols, and availability tied to user intent rather than system suspension.
+    private func updatePlaybackMenu() {
+        playbackItem.title = playback.isRequested ? "Stop Wallpaper" : "Start Wallpaper"
+        playbackItem.image = NSImage(systemSymbolName: playback.isRequested ? "stop.fill" : "play.fill", accessibilityDescription: nil)
+        pauseItem.title = playback.isPaused ? "Resume Animation" : "Pause Animation"
+        pauseItem.image = NSImage(systemSymbolName: playback.isPaused ? "play.fill" : "pause.fill", accessibilityDescription: nil)
+        pauseItem.isEnabled = playback.isRequested
+    }
+
     /// Changes desktop ownership without coupling it to transient animation windows.
     /// - Parameter restoring: Restores originals instead of acquiring newly connected desktops.
     private func updateDesktopWallpaper(restoring: Bool) {
@@ -427,7 +513,7 @@ final class WallpaperApp: NSObject, NSApplicationDelegate, NSMenuDelegate {
     ///
     /// - Parameter displayID: Display requested through the sandbox-safe discovery notification.
     private func shareFrames(for displayID: UInt32) {
-        guard defaults.bool(forKey: Self.syncPreferenceKey), playback.isRequested,
+        guard versionStatus?.state != .mismatch, defaults.bool(forKey: Self.syncPreferenceKey), playback.isRequested,
               currentDisplayLayout.contains(where: { $0.id == displayID }) else { return }
         let starting = !playback.isServingScreenSaver
         if starting {
@@ -463,6 +549,12 @@ final class WallpaperApp: NSObject, NSApplicationDelegate, NSMenuDelegate {
         playback.isRequested = false
         frameLeaseTimer?.invalidate()
         frameLeaseTimer = nil
+        versionRefreshTimer?.invalidate()
+        versionRefreshTimer = nil
+        if let versionAlert {
+            NSApp.abortModal()
+            versionAlert.window.orderOut(nil)
+        }
         for (center, token) in observers { center.removeObserver(token) }
         observers.removeAll()
         // Installers request Quit too; a recovery error must not hold termination in a modal loop.
diff --git a/Tests/Homebrew/documentation_test.py b/Tests/Homebrew/documentation_test.py
index 738686a..f805519 100644
--- a/Tests/Homebrew/documentation_test.py
+++ b/Tests/Homebrew/documentation_test.py
@@ -20,6 +20,15 @@ def test_user_lifecycle_and_security(self):
         self.assertIn("https://www.buymeacoffee.com/yesman82", text)
         self.assertIn("docs/bmc_qr.png", text)
 
+    def test_wallpaper_internals_live_in_developer_notes(self):
+        readme = (ROOT / "README.md").read_text()
+        developer = (ROOT / "docs/development.md").read_text()
+        self.assertIn("(docs/development.md)", readme)
+        for detail in ["dev.patsch.MatrixWallpaper", "Disconnected displays and failed restores",
+                       "Checks compare the loaded host", "restoring the previous installation if replacement fails"]:
+            self.assertNotIn(detail, readme)
+            self.assertIn(detail, developer)
+
     def test_maintainer_permissions_and_compatibility(self):
         text = (ROOT / "Homebrew/README.md").read_text()
         for phrase in ["HOMEBREW_TAP_REPOSITORY", "HOMEBREW_TAP_TOKEN", "contents",
diff --git a/Tests/MatrixScreenSaverTests/MatrixVersionStatusTests.swift b/Tests/MatrixScreenSaverTests/MatrixVersionStatusTests.swift
new file mode 100644
index 0000000..ced03ab
--- /dev/null
+++ b/Tests/MatrixScreenSaverTests/MatrixVersionStatusTests.swift
@@ -0,0 +1,62 @@
+import Foundation
+
+/// Exercises installed metadata without changing real bundles or shared preferences.
+func matrixVersionStatusTests() {
+    let root = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+    defer { try? FileManager.default.removeItem(at: root) }
+    let user = root.appendingPathComponent("user")
+    let local = root.appendingPathComponent("local")
+
+    func install(_ url: URL, identifier: String, version: String?) -> URL {
+        let contents = url.appendingPathComponent("Contents")
+        try! FileManager.default.createDirectory(at: contents, withIntermediateDirectories: true)
+        var metadata = ["CFBundleIdentifier": identifier, "CFBundlePackageType": "BNDL"]
+        metadata["CFBundleShortVersionString"] = version
+        let data = try! PropertyListSerialization.data(fromPropertyList: metadata, format: .xml, options: 0)
+        try! data.write(to: contents.appendingPathComponent("Info.plist"))
+        return url
+    }
+
+    let wallpaper = install(root.appendingPathComponent("Wallpaper.app"), identifier: "dev.patsch.MatrixWallpaper", version: "1.4.0")
+    let host = Bundle(url: wallpaper)!
+    func status() -> MatrixVersionStatus {
+        MatrixVersionStatus.current(hostBundle: host, screenSaverDirectories: [user, local], wallpaperURLs: [])
+    }
+    ok(status().state == .missingCompanion, "wallpaper alone is not a version mismatch")
+    let saver = install(user.appendingPathComponent("Renamed.saver"), identifier: "dev.patsch.MatrixScreenSaver", version: " 1.4.0\n")
+    ok(status().state == .matching, "renamed saver with whitespace-trimmed matching version is recognized")
+    _ = install(saver, identifier: "dev.patsch.MatrixScreenSaver", version: "1.3.0")
+    ok(status().state == .mismatch && status().message.contains("1.3.0") && status().message.contains("1.4.0"),
+       "replacing installed saver refreshes versions without Bundle metadata caching")
+    _ = install(saver, identifier: "dev.patsch.MatrixScreenSaver", version: "1.5.0")
+    ok(status().state == .mismatch, "newer saver also triggers mismatch")
+    _ = install(saver, identifier: "dev.patsch.MatrixScreenSaver", version: nil)
+    ok(status().state == .unverified && status().message.contains("Version unavailable"), "missing version is unverified rather than compatible")
+    _ = install(saver, identifier: "test.unrelated", version: "0.1.0")
+    ok(status().state == .missingCompanion, "matching filename cannot substitute for bundle identity")
+    try! Data("not a plist".utf8).write(to: saver.appendingPathComponent("Contents/Info.plist"))
+    ok(status().state != .mismatch, "malformed metadata never invents a version mismatch")
+    _ = install(saver, identifier: "dev.patsch.MatrixScreenSaver", version: "1.4.0")
+    let duplicate = install(local.appendingPathComponent("Other.saver"), identifier: "dev.patsch.MatrixScreenSaver", version: "1.2.0")
+    ok(status().state == .mismatch && status().screenSavers.contains { $0.url == duplicate.resolvingSymlinksInPath() }, "different installed copies retain their paths")
+    try! FileManager.default.removeItem(at: duplicate)
+    try! FileManager.default.createSymbolicLink(at: duplicate, withDestinationURL: saver)
+    ok(status().state == .matching && status().screenSavers.count == 1, "symlinks to the same installation are deduplicated")
+
+    let saverHostURL = install(root.appendingPathComponent("Loaded.saver"), identifier: "dev.patsch.MatrixScreenSaver", version: "1.1.0")
+    let saverHost = Bundle(url: saverHostURL)!
+    _ = saverHost.infoDictionary
+    _ = install(saverHostURL, identifier: "dev.patsch.MatrixScreenSaver", version: "1.4.0")
+    let fromSaver = MatrixVersionStatus.current(hostBundle: saverHost, screenSaverDirectories: [], wallpaperURLs: [wallpaper])
+    ok(fromSaver.state == .mismatch && fromSaver.screenSavers.first?.version == "1.1.0",
+       "screen saver compares its loaded metadata rather than the system host or replacement on disk")
+    let matchingWallpaper = install(root.appendingPathComponent("Matching.app"), identifier: "dev.patsch.MatrixWallpaper", version: "1.1.0")
+    let multiple = MatrixVersionStatus.current(hostBundle: saverHost, screenSaverDirectories: [],
+                                              wallpaperURLs: [matchingWallpaper, wallpaper, matchingWallpaper])
+    ok(multiple.state == .mismatch && multiple.wallpapers.count == 2 && multiple.wallpapers.contains { $0.url == wallpaper.resolvingSymlinksInPath() },
+       "a matching wallpaper candidate cannot hide a differently versioned copy")
+    let alone = MatrixVersionStatus.current(hostBundle: saverHost, screenSaverDirectories: [], wallpaperURLs: [])
+    ok(alone.state == .missingCompanion, "screen saver alone is not a mismatch")
+    try! FileManager.default.removeItem(at: saver)
+    ok(status().state != .mismatch, "removing saver clears mismatch even with a dangling symlink")
+}
diff --git a/Tests/MatrixScreenSaverTests/main.swift b/Tests/MatrixScreenSaverTests/main.swift
index a88752c..5a62969 100644
--- a/Tests/MatrixScreenSaverTests/main.swift
+++ b/Tests/MatrixScreenSaverTests/main.swift
@@ -21,6 +21,7 @@ cmdCaptureSceneTests()
 nativeMatrixRendererTests()
 wallpaperPlaybackStateTests()
 sharedWallpaperFrameTests()
+matrixVersionStatusTests()
 
 print("1..\(testCount)")
 exit(failCount == 0 ? 0 : 1)
diff --git a/Tests/MatrixWallpaperTests/ConsumerHost.swift b/Tests/MatrixWallpaperTests/ConsumerHost.swift
index 92eb0a7..78cd7ea 100644
--- a/Tests/MatrixWallpaperTests/ConsumerHost.swift
+++ b/Tests/MatrixWallpaperTests/ConsumerHost.swift
@@ -22,6 +22,13 @@ func consumerHostTests() {
     // An unattached-to-window canvas uses display 0, isolating discovery from live wallpaper displays.
     let container = NSView(frame: NSRect(x: 0, y: 0, width: 437, height: 293))
     let view = MatrixScreenSaverView(frame: container.bounds, isPreview: false)!
+    var mismatch = false
+    view.readVersionStatus = {
+        MatrixVersionStatus(wallpapers: [.init(url: URL(fileURLWithPath: "/Wallpaper.app"), version: "1.0", isLoaded: false)],
+                            screenSavers: [.init(url: URL(fileURLWithPath: "/ScreenSaver.saver"),
+                                                 version: mismatch ? "2.0" : "1.0", isLoaded: true)],
+                            discoveryIncomplete: false)
+    }
     container.addSubview(view)
     view.startAnimation()
     defer { view.stopAnimation(); view.removeFromSuperview() }
@@ -56,6 +63,22 @@ func consumerHostTests() {
     check(stored("frameIndex", in: renderer, as: Int.self) == frameIndex,
           "shared frame ticks do not advance native simulation")
 
+    let sharedPixels = pixels(of: view)
+    mismatch = true
+    view.refreshVersionStatus()
+    publish(0.4)
+    wait(0.1)
+    view.animateOneFrame()
+    check(stored("wallpaperFrameReader", in: view, as: WallpaperFrameReader.self) == nil &&
+          stored("sharedWallpaperImage", in: view, as: CGImage.self) == nil &&
+          stored("running", in: renderer, as: Bool.self) == false && pixels(of: view) != sharedPixels,
+          "mismatch tears down the real consumer and replaces shared frames with the error screen")
+    mismatch = false
+    view.refreshVersionStatus()
+    publish(0.75)
+    check(eventually { view.animateOneFrame(); return stored("sharedWallpaperImage", in: view, as: CGImage.self) != nil },
+          "matching versions reacquire wallpaper frames after a consumer mismatch")
+
     let nativeContainers = (1..<max(NSScreen.screens.count, 1)).map { index -> NSView in
         let container = NSView(frame: NSRect(x: 0, y: 0, width: 503 + index, height: 347))
         let native = MatrixScreenSaverView(frame: container.bounds, isPreview: false)!
@@ -115,4 +138,9 @@ func consumerHostTests() {
     nativeViews.forEach { $0.stopAnimation() }
     check(ScreenSyncCoordinator.shared.registeredCount == 0 && ScreenSyncCoordinator.shared.expected == 0,
           "consumer teardown clears synchronization state")
+    mismatch = true
+    view.startAnimation()
+    check(stored("wallpaperFrameReader", in: view, as: WallpaperFrameReader.self) == nil &&
+          stored("running", in: renderer, as: Bool.self) == false,
+          "mismatched startup in the real saver host never starts discovery or Matrix playback")
 }
diff --git a/Tests/MatrixWallpaperTests/SharedSaverTests.swift b/Tests/MatrixWallpaperTests/SharedSaverTests.swift
index 3f585c7..cc96df0 100644
--- a/Tests/MatrixWallpaperTests/SharedSaverTests.swift
+++ b/Tests/MatrixWallpaperTests/SharedSaverTests.swift
@@ -112,8 +112,19 @@ func sharedSaverTests() {
     check(shuffleRadio?.state == .on && randomRadio?.state == .off && sequenceRadio?.state == .off,
           "shuffled playback is mutually exclusive with the existing modes")
     checkOptionsLayout(in: controller.configureSheet())
+    check(buttons(in: controller.configureSheet().contentView!).first {
+        $0.action == NSSelectorFromString("openRepository:")
+    }?.title == "About the project", "options project link uses the requested label")
+    let donationButton = buttons(in: controller.configureSheet().contentView!).first {
+        $0.action == NSSelectorFromString("openDonationPage:")
+    }
+    check(donationButton?.title == "Buy Me a Coffee" && donationButton?.imagePosition == .imageLeft &&
+          donationButton?.image?.size == NSSize(width: 16, height: 16) && donationButton?.image?.isTemplate == false,
+          "options donation button uses the full-color favicon at 16 points before its title")
+    check(donationButton.map { $0.frame.width >= $0.intrinsicContentSize.width + 8 } == true,
+          "options donation button leaves extra space between its icon and centered label")
     checkSceneOptions(controller, options: options)
-    let applyButton = buttons(in: controller.configureSheet().contentView!).first { $0.title == "OK" }
+    let applyButton = buttons(in: controller.configureSheet().contentView!).first { $0.title == "Save" }
     check(applyButton != nil, "native options window exposes Apply")
     applyButton?.performClick(nil)
     let loaded = MatrixScreenSaverOptions.load(from: defaults)
@@ -128,7 +139,7 @@ func sharedSaverTests() {
     var cancelApplied = false
     let cancelController = MatrixScreenSaverOptionsSheetController { _ in cancelApplied = true }
     cancelController.prepare(using: options)
-    buttons(in: cancelController.configureSheet().contentView!).first { $0.title == "Reset to defaults" }!.performClick(nil)
+    buttons(in: cancelController.configureSheet().contentView!).first { $0.title == "Restore Defaults" }!.performClick(nil)
     buttons(in: cancelController.configureSheet().contentView!).first { $0.title == "Cancel" }!.performClick(nil)
     check(!cancelApplied && MatrixScreenSaverOptions.load(from: defaults).commands == options.commands,
           "main Cancel discards edits without invoking persistence")
@@ -288,7 +299,7 @@ private func rainFontResetTests() {
     check(picker?.title.hasPrefix("Default - ") == true && picker?.menu?.items[1].state == .on &&
           picker?.menu?.items.filter { $0.representedObject is String }.allSatisfy { $0.state == .off } == true,
           "font reset restores the system-font summary and clears custom-font checkmarks")
-    buttons(in: window.contentView!).first { $0.title == "OK" }?.performClick(nil)
+    buttons(in: window.contentView!).first { $0.title == "Save" }?.performClick(nil)
     check(applied?.rainFonts.isEmpty == true && applied?.characters == "ATGC" && applied?.frameRate == 42,
           "font reset applies the default font without changing other options")
 }
@@ -345,9 +356,11 @@ private func rainGlyphOptionsTests() {
         check(preview?.font?.fontName == expectedFont, "\(radio.title) preview uses its current rendering font")
     }
     window.contentView!.layoutSubtreeIfNeeded()
-    check(preview != nil && preview!.frame.height > (preview!.font?.pointSize ?? 0) * 1.5 && (rainTab.view as? NSScrollView)?.hasVerticalScroller == true,
-          "long glyph sets wrap onto multiple lines in a scrollable Rain tab")
-    buttons(in: window.contentView!).first { $0.title == "OK" }?.performClick(nil)
+    check(preview != nil && preview!.maximumNumberOfLines == 3 && !(rainTab.view is NSScrollView)
+          && descendants(of: rainTab.view!).compactMap { $0 as? NSControl }.allSatisfy {
+              rainTab.view!.bounds.contains($0.convert($0.bounds, to: rainTab.view!))
+          }, "film glyph samples and all Rain settings fit without scrolling")
+    buttons(in: window.contentView!).first { $0.title == "Save" }?.performClick(nil)
     check(applied?.rainGlyphSet == .resurrections && applied?.rainFonts == ["Menlo"] && applied?.characters == "ATGC",
           "accepting a film preset keeps custom fonts and characters for switching back")
     controller.prepare(using: applied!)
@@ -364,10 +377,20 @@ private func rainGlyphOptionsTests() {
     reset?.performClick(nil)
     check(preview?.font?.fontName == NSFont.monospacedSystemFont(ofSize: 16, weight: .medium).fontName,
           "font Reset restores the system typeface in the preview")
+    characters?.stringValue = ""
+    controller.controlTextDidChange(Notification(name: NSControl.textDidChangeNotification, object: characters))
+    if let menu = picker?.menu, let index = menu.items.firstIndex(where: { $0.representedObject as? String == "Hiragino Sans" }) {
+        menu.performActionForItem(at: index)
+    }
+    window.contentView!.layoutSubtreeIfNeeded()
+    check((preview?.stringValue.count ?? 0) > 135
+          && descendants(of: rainTab.view!).compactMap { $0 as? NSControl }.allSatisfy {
+              rainTab.view!.bounds.contains($0.convert($0.bounds, to: rainTab.view!))
+          }, "large font repertoires remain a bounded sample without hiding Rain settings")
     var cancelled = false
     let cancelController = MatrixScreenSaverOptionsSheetController { _ in cancelled = true }
     cancelController.prepare(using: options)
-    buttons(in: cancelController.configureSheet().contentView!).first { $0.title == "Reset to defaults" }?.performClick(nil)
+    buttons(in: cancelController.configureSheet().contentView!).first { $0.title == "Restore Defaults" }?.performClick(nil)
     let resetRadios: [NSButton] = stored("rainGlyphRadios", in: cancelController) ?? []
     check(resetRadios.first?.state == .on, "Reset to defaults restores the default glyph set")
     buttons(in: cancelController.configureSheet().contentView!).first { $0.title == "Cancel" }?.performClick(nil)
@@ -396,6 +419,7 @@ private func glyphCacheTests() {
     check(original === glyph("A"), "frame-rate changes preserve glyph rasters")
     // These checks exercise plain scalar keys, independent of the user's saved font selection.
     options.rainFonts = []
+    options.rainGlyphSet = .default
     options.characters = "☃"
     view.applyWallpaperOptions(options)
     check(glyph("☃") != nil && glyph("☃", bold: true) != nil,
@@ -525,18 +549,32 @@ private func checkOptionsLayout(in window: NSWindow) {
     let content = window.contentView!
     content.layoutSubtreeIfNeeded()
     let size = content.bounds.size
-    // The Rain tab gained the Fonts section, so the sheet is taller than the original 600 point budget.
-    check(size.width <= 600 && size.height <= 650,
-          "options fit in a compact window without screen-sized help text")
+    check(size.width <= 720 && size.height <= 800,
+          "options fit all settings in a fixed desktop-sized window")
     guard let tabs = descendants(of: content).compactMap({ $0 as? NSTabView }).first else {
         check(false, "options organize settings into native tabs")
         return
     }
     check(tabs.tabViewItems.map(\.label) == ["General", "Intro scenes", "Rain"],
           "command capture integrates into the current native tab structure")
+    let general = tabs.tabViewItems[0].view!
+    let rain = tabs.tabViewItems[2].view!
+    check(buttons(in: general).contains { $0.title == "Twinkling effect" }
+          && !buttons(in: rain).contains { $0.title == "Twinkling effect" },
+          "twinkle belongs to shared settings because it affects rain and trace")
+    check(!descendants(of: general).contains { $0.accessibilityLabel() == "Font" }
+          && descendants(of: rain).contains { $0.accessibilityLabel() == "Font" }
+          && descendants(of: rain).contains { $0.accessibilityLabel() == "Custom glyphs" },
+          "rain owns its font and custom glyph controls")
+    let save = buttons(in: content).first { $0.title == "Save" }
+    let cancel = buttons(in: content).first { $0.title == "Cancel" }
+    check(save?.keyEquivalent == "\r" && cancel?.keyEquivalent == "\u{1b}",
+          "Save and Cancel retain standard Return and Escape shortcuts")
+    check(!window.styleMask.contains(.resizable), "options window has a fixed size")
     for item in tabs.tabViewItems {
         tabs.selectTabViewItem(item)
         content.layoutSubtreeIfNeeded()
+        check(!(item.view is NSScrollView), "\(item.label) exposes all settings without scrolling")
         let page = (item.view as? NSScrollView)?.documentView ?? item.view!
         let controls = descendants(of: page).compactMap { $0 as? NSControl }
         check(!controls.isEmpty && controls.allSatisfy { page.bounds.contains($0.convert($0.bounds, to: page)) },
@@ -574,7 +612,7 @@ private func checkSceneOptions(_ controller: MatrixScreenSaverOptionsSheetContro
     let groups = descendants(of: page).compactMap { $0 as? NSBox }
     check(groups.count == 3, "intro scenes have three native fieldsets")
     guard groups.count == 3 else { return }
-    let titles = ["Show Neo message scene", "Show custom scene", "Show trace program scene"]
+    let titles = ["Show Neo message", "Run custom commands", "Show trace program"]
     check(groups.map { buttons(in: $0).first?.title ?? "" } == titles,
           "fieldsets follow Neo, custom, trace playback order")
     for group in groups {
@@ -586,13 +624,11 @@ private func checkSceneOptions(_ controller: MatrixScreenSaverOptionsSheetContro
             zip(stack.arrangedSubviews, stack.arrangedSubviews.dropFirst()).allSatisfy { $0.frame.minY >= $1.frame.maxY }
         }, "fieldset rows do not overlap")
     }
-    let customCopy = "Execute custom commands and show its output as messages. Off by default."
     let labels = descendants(of: groups[1]).compactMap { $0 as? NSTextField }
     check(labels.contains { $0.isEditable && $0.accessibilityLabel() == "Command output hold in seconds" && $0.stringValue == "4.5" }
           && !labels.contains { $0.stringValue == "Typing speed" || $0.accessibilityLabel() == "Custom typing speed" },
           "custom fieldset replaces independent typing speed with an output hold control")
-    check(labels.filter { $0.stringValue == customCopy }.count == 1
-          && labels.contains { $0.stringValue == "Commands" }, "custom group has exact description and separate Commands row")
+    check(labels.contains { $0.stringValue == "Commands" }, "custom group has a separate Commands editor row")
     check(descendants(of: groups[0]).compactMap { $0 as? NSTextField }.contains { $0.stringValue == "Lines" },
           "Neo fieldset owns its Lines editor")
     let speed = descendants(of: page).compactMap { $0 as? NSTextField }.first { $0.isEditable && $0.stringValue == "2" }!
@@ -667,12 +703,15 @@ private func checkSceneOptions(_ controller: MatrixScreenSaverOptionsSheetContro
     } else {
         check(false, "custom Edit opens a native editor sheet")
     }
-    buttons(in: window.contentView!).first { $0.title == "Reset to defaults" }!.performClick(nil)
+    let originalSize = window.contentView!.bounds.size
+    buttons(in: window.contentView!).first { $0.title == "Restore Defaults" }!.performClick(nil)
+    check(window.contentView!.bounds.size == originalSize, "Restore Defaults preserves the fixed window size")
     check(buttons(in: groups[0]).first!.state == .on && name.isEnabled
           && buttons(in: groups[1]).first!.state == .off && !customEdit.isEnabled
           && buttons(in: groups[2]).first!.state == .on && speed.isEnabled,
           "Reset restores scene enablement and leaves shared speed editable")
     controller.prepare(using: options)
+    check(window.contentView!.bounds.size == originalSize, "refreshing options preserves the fixed window size")
     tabs.selectTabViewItem(at: 0)
 }
 
diff --git a/Tests/MatrixWallpaperTests/VersionWarningTests.swift b/Tests/MatrixWallpaperTests/VersionWarningTests.swift
new file mode 100644
index 0000000..2ea3207
--- /dev/null
+++ b/Tests/MatrixWallpaperTests/VersionWarningTests.swift
@@ -0,0 +1,356 @@
+import AppKit
+
+/// Uses real temporary bundle metadata for both native presentation paths.
+private final class VersionWarningFixture {
+    let root = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+    let hostBundle: Bundle
+    let saverDirectory: URL
+
+    init() {
+        let appURL = root.appendingPathComponent("Wallpaper.app")
+        saverDirectory = root.appendingPathComponent("Screen Savers")
+        Self.write(appURL, identifier: "dev.patsch.MatrixWallpaper", version: "1.4.0")
+        hostBundle = Bundle(url: appURL)!
+        installSaver("1.3.0")
+    }
+
+    deinit { try? FileManager.default.removeItem(at: root) }
+
+    func installSaver(_ version: String?) {
+        Self.write(saverDirectory.appendingPathComponent("Renamed.saver"), identifier: "dev.patsch.MatrixScreenSaver", version: version)
+    }
+
+    func read() -> MatrixVersionStatus {
+        MatrixVersionStatus.current(hostBundle: hostBundle, screenSaverDirectories: [saverDirectory], wallpaperURLs: [])
+    }
+
+    private static func write(_ url: URL, identifier: String, version: String?) {
+        let contents = url.appendingPathComponent("Contents")
+        try! FileManager.default.createDirectory(at: contents, withIntermediateDirectories: true)
+        var metadata = ["CFBundleIdentifier": identifier, "CFBundlePackageType": "BNDL"]
+        metadata["CFBundleShortVersionString"] = version
+        let data = try! PropertyListSerialization.data(fromPropertyList: metadata, format: .xml, options: 0)
+        try! data.write(to: contents.appendingPathComponent("Info.plist"))
+    }
+}
+
+/// Checks the shared banner, launch-only alert, menu, icon, and refresh lifecycle.
+func versionWarningTests() {
+    versionOptionsTests()
+    versionBlockedSaverTests()
+    versionWallpaperTests()
+}
+
+private func versionOptionsTests() {
+    let fixture = VersionWarningFixture()
+    var applied: MatrixScreenSaverOptions?
+    let controller = MatrixScreenSaverOptionsSheetController(readVersionStatus: fixture.read) { applied = $0 }
+    controller.prepare(using: MatrixScreenSaverOptions())
+    let window = controller.configureSheet()
+    window.center()
+    window.makeKeyAndOrderFront(nil)
+    defer { window.orderOut(nil) }
+    let banner: NSStackView = stored("versionBanner", in: controller)!
+    let description: NSTextField = stored("versionDescription", in: controller)!
+    let heading: NSTextField = stored("versionHeading", in: controller)!
+    let symbol: NSImageView = stored("versionSymbol", in: controller)!
+    let name: NSTextField = stored("nameField", in: controller)!
+    let scroll: NSScrollView = stored("optionsScrollView", in: controller)!
+    let tabs = scroll.documentView as! NSTabView
+    let content = window.contentView!
+    check(!banner.isHidden && heading.stringValue == "Version Mismatch" &&
+          description.stringValue.contains("1.4.0") && description.stringValue.contains("1.3.0"),
+          "options show an explicit mismatch and both versions")
+    check(description.isSelectable && description.stringValue.count < 110,
+          "options keep version information selectable and concise")
+    check(symbol.image === NSImage(named: NSImage.cautionName), "options use the standard macOS warning triangle")
+    check(versionDescendants(banner).compactMap { $0 as? NSButton }.map(\.title) == ["View Releases…"],
+          "the options banner offers only View Releases without a redundant Details button")
+    for appearance in [NSAppearance.Name.aqua, .darkAqua] {
+        window.appearance = NSAppearance(named: appearance)
+        for item in tabs.tabViewItems {
+            tabs.selectTabViewItem(item)
+            content.layoutSubtreeIfNeeded()
+            check(!banner.isHidden && content.bounds.contains(banner.convert(banner.bounds, to: content)) &&
+                  banner.convert(banner.bounds, to: content).minY >= scroll.convert(scroll.bounds, to: content).maxY,
+                  "\(item.label) keeps the warning above its scrollable settings in \(appearance.rawValue)")
+        }
+        captureVersionView(content, name: "options-\(appearance.rawValue)")
+    }
+    let controls = versionDescendants(content).compactMap { $0 as? NSButton }
+    let save = controls.first { $0.title == "Save" }!
+    let cancel = controls.first { $0.title == "Cancel" }!
+    check(save.isEnabled && cancel.isEnabled && save.keyEquivalent == "\r" && cancel.keyEquivalent == "\u{1b}",
+          "mismatch preserves Save, Cancel, and their standard keyboard equivalents")
+    check(content.bounds.contains(save.convert(save.bounds, to: content)) &&
+          window.frame.height <= (window.screen?.visibleFrame.height ?? .infinity),
+          "warning layout keeps actions inside the window and fits the current display")
+    name.stringValue = "Unsaved Trinity"
+    fixture.installSaver("1.4.0")
+    controller.windowDidBecomeKey(Notification(name: NSWindow.didBecomeKeyNotification, object: window))
+    check(banner.isHidden && name.stringValue == "Unsaved Trinity", "reactivating options clears resolved mismatch without losing edits")
+    fixture.installSaver(nil)
+    _ = controller.configureSheet()
+    check(!banner.isHidden && heading.stringValue == "Version Unavailable" && description.stringValue.contains("Version unavailable"),
+          "unreadable version is explained in options without claiming a mismatch")
+    fixture.installSaver("1.3.0")
+    _ = controller.configureSheet()
+    save.performClick(nil)
+    check(applied?.name == "Unsaved Trinity", "Save still delivers edited options during mismatch")
+    var cancelledApply = false
+    let cancelling = MatrixScreenSaverOptionsSheetController(readVersionStatus: fixture.read) { _ in cancelledApply = true }
+    cancelling.prepare(using: MatrixScreenSaverOptions())
+    let cancelWindow = cancelling.configureSheet()
+    versionDescendants(cancelWindow.contentView!).compactMap { $0 as? NSButton }.first { $0.title == "Cancel" }?.performClick(nil)
+    check(!cancelledApply, "Cancel during mismatch does not apply preferences")
+}
+
+private func versionWallpaperTests() {
+    let fixture = VersionWarningFixture()
+    let suite = "MatrixVersionWarnings.\(UUID().uuidString)"
+    let defaults = UserDefaults(suiteName: suite)!
+    defer { defaults.removePersistentDomain(forName: suite) }
+    let desktop = DesktopWallpaperFixture()
+    var alerts = 0
+    var host: WallpaperApp!
+    host = WallpaperApp(defaults: defaults, desktopWallpaper: desktop.controller(), readVersionStatus: fixture.read,
+                        presentVersionAlert: { alert in
+        alerts += 1
+        check(alert.messageText == "Version Mismatch" && alert.informativeText.count < 110 &&
+              alert.informativeText.contains("1.4.0") && alert.informativeText.contains("1.3.0") &&
+              alert.buttons.map(\.title) == ["View Releases…", "Close"],
+              "short error dialog shows versions and offers releases or Close")
+        check(alert.alertStyle == .warning && alert.icon === NSImage(named: NSImage.cautionName),
+              "version dialog uses the standard macOS warning triangle")
+        do {
+            let dismiss = Timer(timeInterval: 0.1, repeats: true) { _ in
+                guard NSApp.modalWindow === alert.window else { return }
+                if alerts == 1 { captureVersionView(alert.window.contentView!, name: "startup-alert") }
+                NSApp.stopModal(withCode: .alertSecondButtonReturn)
+            }
+            RunLoop.main.add(dismiss, forMode: .modalPanel)
+            defer { dismiss.invalidate() }
+            let response = alert.runModal()
+            alert.window.orderOut(nil)
+            return response
+        }
+    })
+    host.applicationDidFinishLaunching(Notification(name: NSApplication.didFinishLaunchingNotification))
+    defer {
+        host.applicationWillTerminate(Notification(name: NSApplication.willTerminateNotification))
+        host = nil
+    }
+    let status: NSStatusItem = stored("statusItem", in: host!)!
+    let menu = status.menu!
+    let warning = menu.items.first { $0.title == "Version Mismatch…" }!
+    check(eventually(5) { alerts == 1 }, "mismatched launch presents one automatic warning")
+    check(eventually {
+        let windows: [DesktopWindow] = stored("windows", in: host!) ?? []
+        return windows.count == NSScreen.screens.count && windows.allSatisfy {
+            ($0.contentView as? MatrixScreenSaverView)?.isAnimating == true
+        }
+    }, "mismatch keeps desktop surfaces available for the moving error symbol")
+    check((stored("windows", in: host!, as: [DesktopWindow].self) ?? []).allSatisfy {
+        guard let view = $0.contentView as? MatrixScreenSaverView,
+              let renderer: NativeMatrixRenderer = stored("nativeRenderer", in: view) else { return false }
+        return stored("running", in: renderer, as: Bool.self) == false && view.shareWallpaperFrames() == nil
+    }, "version mismatch blocks Matrix simulation and frame sharing")
+    check(menu.items.filter { !$0.isHidden }.first === warning && warning.image != nil &&
+          status.button?.accessibilityLabel() == "Matrix Wallpaper — version mismatch",
+          "mismatch leads the menu and exposes a non-color status warning to accessibility")
+    let visibleItems = menu.items.filter { !$0.isHidden }
+    check(visibleItems.prefix(3).map(\.title) == ["Version Mismatch…", "", "Pause Animation"] && visibleItems[1].isSeparatorItem,
+          "the mismatch menu section contains exactly one item followed by a separator")
+    check(warning.image?.isTemplate == false && warning.image?.size == NSSize(width: 18, height: 18),
+          "the first menu item uses a full-color warning image sized for the menu")
+    if warning.responds(to: NSSelectorFromString("setPreferredImageVisibility:")) {
+        check(warning.value(forKey: "preferredImageVisibility") as? Int == 1,
+              "macOS 27 is instructed to keep the mismatch icon visible")
+    }
+    captureVersionMenu(menu)
+    let warningImage = status.button?.image
+    check(warningImage != nil && status.button?.toolTip == nil && warning.toolTip == nil,
+          "persistent error icon has no menu or status-button hover text")
+    menu.delegate?.menuWillOpen?(menu)
+    let timer: Timer = stored("versionRefreshTimer", in: host!)!
+    timer.fire()
+    check(alerts == 1, "menu opening and periodic refresh do not repeat startup warning")
+    menu.performActionForItem(at: menu.index(of: warning))
+    check(alerts == 2, "menu warning can explicitly reopen version details")
+    check((stored("windows", in: host!, as: [DesktopWindow].self) ?? []).allSatisfy {
+        ($0.contentView as? MatrixScreenSaverView)?.isAnimating == true
+    }, "dismissing the menu error preserves the moving error screen")
+    NSApp.sendAction(NSSelectorFromString("togglePause:"), to: host, from: nil)
+    wait(1.2)
+    fixture.installSaver("1.4.0")
+    timer.fire()
+    check((stored("windows", in: host!, as: [DesktopWindow].self) ?? []).allSatisfy {
+        ($0.contentView as? MatrixScreenSaverView)?.isAnimating == false
+    }, "resolving a mismatch preserves manual pause")
+    NSApp.sendAction(NSSelectorFromString("togglePause:"), to: host, from: nil)
+    check(warning.isHidden && status.button?.image !== warningImage && status.button?.toolTip == nil,
+          "periodic refresh restores the normal icon and hides warning after matching update")
+    check(eventually(0.3) {
+        for window in stored("windows", in: host!, as: [DesktopWindow].self) ?? [] {
+            guard let view = window.contentView as? MatrixScreenSaverView,
+                  let renderer: NativeMatrixRenderer = stored("nativeRenderer", in: view) else { return false }
+            view.animateOneFrame()
+            if stored("running", in: renderer, as: Bool.self) != true { return false }
+        }
+        return true
+    }, "Resume after resolving a paused mismatch does not wait through the old pause again")
+    fixture.installSaver(nil)
+    timer.fire()
+    check(warning.isHidden && alerts == 2, "unknown version is not a confirmed menu mismatch or repeated alert")
+    fixture.installSaver("1.3.0")
+    timer.fire()
+    check(!warning.isHidden && alerts == 2, "new mismatch while running updates persistent warnings without another startup alert")
+    check((stored("windows", in: host!, as: [DesktopWindow].self) ?? []).allSatisfy {
+        guard let view = $0.contentView as? MatrixScreenSaverView,
+              let renderer: NativeMatrixRenderer = stored("nativeRenderer", in: view) else { return false }
+        return stored("running", in: renderer, as: Bool.self) == false && view.shareWallpaperFrames() == nil
+    }, "a mismatch found during playback stops Matrix and prevents shared frames")
+    host.applicationWillTerminate(Notification(name: NSApplication.willTerminateNotification))
+    check(!timer.isValid, "termination invalidates version refresh timer")
+
+    var cancelledAlerts = 0
+    let cancelled = WallpaperApp(defaults: defaults, desktopWallpaper: desktop.controller(), readVersionStatus: fixture.read,
+                                 presentVersionAlert: { _ in cancelledAlerts += 1; return .alertSecondButtonReturn })
+    cancelled.applicationDidFinishLaunching(Notification(name: NSApplication.didFinishLaunchingNotification))
+    cancelled.applicationWillTerminate(Notification(name: NSApplication.willTerminateNotification))
+    wait(0.1)
+    check(cancelledAlerts == 0, "Quit before queued startup suppresses the pending warning")
+
+    var quitDuringAlert: WallpaperApp!
+    var modalReturned = false
+    quitDuringAlert = WallpaperApp(defaults: defaults, desktopWallpaper: desktop.controller(), readVersionStatus: fixture.read,
+                                  presentVersionAlert: { alert in
+        let quit = Timer(timeInterval: 0.1, repeats: true) { _ in
+            guard NSApp.modalWindow === alert.window else { return }
+            quitDuringAlert.applicationWillTerminate(Notification(name: NSApplication.willTerminateNotification))
+        }
+        RunLoop.main.add(quit, forMode: .modalPanel)
+        defer { quit.invalidate() }
+        let result = alert.runModal()
+        modalReturned = true
+        return result
+    })
+    quitDuringAlert.applicationDidFinishLaunching(Notification(name: NSApplication.didFinishLaunchingNotification))
+    check(eventually { modalReturned } && NSApp.modalWindow == nil &&
+          (stored("windows", in: quitDuringAlert!, as: [DesktopWindow].self) ?? []).isEmpty,
+          "Quit during the warning unwinds its modal loop without starting wallpaper")
+    quitDuringAlert = nil
+
+    for companion in ["matching", "missing"] {
+        if companion == "matching" { fixture.installSaver("1.4.0") }
+        else { try! FileManager.default.removeItem(at: fixture.saverDirectory) }
+        var unexpectedAlerts = 0
+        let normal = WallpaperApp(defaults: defaults, desktopWallpaper: desktop.controller(), readVersionStatus: fixture.read,
+                                  presentVersionAlert: { _ in unexpectedAlerts += 1; return .alertSecondButtonReturn })
+        normal.applicationDidFinishLaunching(Notification(name: NSApplication.didFinishLaunchingNotification))
+        check(eventually { (stored("windows", in: normal, as: [DesktopWindow].self) ?? []).count == NSScreen.screens.count }
+              && unexpectedAlerts == 0, "\(companion) companion launches without a version alert")
+        normal.applicationWillTerminate(Notification(name: NSApplication.willTerminateNotification))
+    }
+}
+
+/// The real saver view must block before starting either its renderer or a wallpaper consumer.
+private func versionBlockedSaverTests() {
+    for preview in [true, false] {
+        let fixture = VersionWarningFixture()
+        let view = MatrixScreenSaverView(frame: NSRect(x: 0, y: 0, width: 320, height: 180), isPreview: preview)!
+        view.readVersionStatus = fixture.read
+        let container = NSView(frame: view.frame)
+        container.addSubview(view)
+        defer { view.stopAnimation(); view.removeFromSuperview() }
+        view.startAnimation()
+        let renderer: NativeMatrixRenderer = stored("nativeRenderer", in: view)!
+        let before = errorBitmap(view)
+        for _ in 0..<90 { view.animateOneFrame() }
+        let after = errorBitmap(view)
+        if let directory = ProcessInfo.processInfo.environment["MATRIX_VERSION_SNAPSHOTS"] {
+            let url = URL(fileURLWithPath: directory).appendingPathComponent("blocked-saver-\(preview).png")
+            try! after.representation(using: .png, properties: [:])!.write(to: url)
+        }
+        let black = after.colorAt(x: 0, y: 0)!.usingColorSpace(.deviceRGB)!
+        let hasYellow = (0..<after.pixelsHigh).contains { y in
+            (0..<after.pixelsWide).contains { x in
+                let color = after.colorAt(x: x, y: y)!.usingColorSpace(.deviceRGB)!
+                return color.redComponent > 0.6 && color.greenComponent > 0.4 && color.blueComponent < 0.3
+            }
+        }
+        check(stored("running", in: renderer, as: Bool.self) == false &&
+              stored("wallpaperFrameReader", in: view, as: WallpaperFrameReader.self) == nil,
+              "saver preview=\(preview) blocks native and shared Matrix playback")
+        check(black.redComponent == 0 && black.greenComponent == 0 && black.blueComponent == 0 && hasYellow,
+              "saver preview=\(preview) renders a yellow warning triangle on black")
+        check((before.representation(using: .png, properties: [:]) == after.representation(using: .png, properties: [:]))
+              == NSWorkspace.shared.accessibilityDisplayShouldReduceMotion,
+              "error symbol moves unless Reduce Motion is enabled")
+        view.applyWallpaperOptions(MatrixScreenSaverOptions())
+        check(stored("running", in: renderer, as: Bool.self) == false,
+              "editing settings cannot bypass the version block")
+        fixture.installSaver("1.4.0")
+        view.refreshVersionStatus()
+        check(stored("running", in: renderer, as: Bool.self) == true,
+              "saver resumes when installed versions match")
+    }
+}
+
+private func errorBitmap(_ view: NSView) -> NSBitmapImageRep {
+    let bitmap = NSBitmapImageRep(bitmapDataPlanes: nil, pixelsWide: Int(view.bounds.width), pixelsHigh: Int(view.bounds.height),
+                                 bitsPerSample: 8, samplesPerPixel: 4, hasAlpha: true, isPlanar: false,
+                                 colorSpaceName: .deviceRGB, bytesPerRow: 0, bitsPerPixel: 0)!
+    NSGraphicsContext.saveGraphicsState()
+    NSGraphicsContext.current = NSGraphicsContext(bitmapImageRep: bitmap)
+    view.draw(view.bounds)
+    NSGraphicsContext.restoreGraphicsState()
+    return bitmap
+}
+
+private func versionDescendants(_ view: NSView) -> [NSView] {
+    view.subviews.flatMap { [$0] + versionDescendants($0) }
+}
+
+/// Captures the opened native menu, where macOS can suppress otherwise assigned item images.
+private func captureVersionMenu(_ menu: NSMenu) {
+    guard let directory = ProcessInfo.processInfo.environment["MATRIX_VERSION_SNAPSHOTS"],
+          let screen = NSScreen.main else { return }
+    for appearance in [NSAppearance.Name.aqua, .darkAqua] {
+        let previous = menu.appearance
+        menu.appearance = NSAppearance(named: appearance)
+        defer { menu.appearance = previous }
+        // Drain the modal dismissal event before entering menu tracking.
+        wait(0.2)
+        var captured = false
+        let capture = Timer(timeInterval: 0.5, repeats: false) { _ in
+            let process = Process()
+            process.executableURL = URL(fileURLWithPath: "/usr/sbin/screencapture")
+            process.arguments = ["-x", "-R", "30,80,340,350", URL(fileURLWithPath: directory).appendingPathComponent("menu-\(appearance.rawValue).png").path]
+            try! process.run()
+            process.waitUntilExit()
+            captured = process.terminationStatus == 0
+            check(process.terminationStatus == 0, "opened native menu snapshot captured in \(appearance.rawValue)")
+            menu.cancelTracking()
+        }
+        RunLoop.main.add(capture, forMode: .eventTracking)
+        menu.popUp(positioning: nil, at: NSPoint(x: screen.visibleFrame.minX + 40, y: screen.visibleFrame.maxY - 80), in: nil)
+        capture.invalidate()
+        check(captured, "menu stayed open long enough to inspect its warning icon")
+    }
+}
+
+/// Optional native snapshots support visual checks without modifying installed applications.
+private func captureVersionView(_ view: NSView, name: String) {
+    guard let directory = ProcessInfo.processInfo.environment["MATRIX_VERSION_SNAPSHOTS"],
+          let window = view.window else { return }
+    view.displayIfNeeded()
+    window.displayIfNeeded()
+    let url = URL(fileURLWithPath: directory).appendingPathComponent(name + ".png")
+    let capture = Process()
+    capture.executableURL = URL(fileURLWithPath: "/usr/sbin/screencapture")
+    capture.arguments = ["-x", "-o", "-l", String(window.windowNumber), url.path]
+    try! capture.run()
+    capture.waitUntilExit()
+    check(capture.terminationStatus == 0, "native window snapshot captured: \(name)")
+}
diff --git a/Tests/MatrixWallpaperTests/WallpaperAppTests.swift b/Tests/MatrixWallpaperTests/WallpaperAppTests.swift
index dd1fcd0..a2afde5 100644
--- a/Tests/MatrixWallpaperTests/WallpaperAppTests.swift
+++ b/Tests/MatrixWallpaperTests/WallpaperAppTests.swift
@@ -15,19 +15,30 @@ func wallpaperAppTests() {
     host.applicationDidFinishLaunching(Notification(name: NSApplication.didFinishLaunchingNotification))
     defer { host.applicationWillTerminate(Notification(name: NSApplication.willTerminateNotification)) }
     let status: NSStatusItem? = stored("statusItem", in: host)
-    let controls = status?.menu?.items.first?.view as? NSStackView
-    let buttons = controls?.arrangedSubviews.compactMap { $0 as? NSButton } ?? []
-    let stopItem = buttons.first
-    let pauseItem = buttons.last
-    check(controls?.orientation == .horizontal && buttons.map(\.title) == ["Stop", "Pause"] &&
-          buttons.allSatisfy { $0.imagePosition == .noImage && $0.bezelStyle == .rounded },
-          "launch shows Stop and Pause as text push buttons in one horizontal menu row")
     let menuItems = status?.menu?.items ?? []
+    let donationItem = menuItems.first { $0.action == NSSelectorFromString("openDonationPage:") }
+    check(donationItem?.title == "Buy Me a Coffee" && donationItem?.image?.size == NSSize(width: 16, height: 16) &&
+          donationItem?.image?.isTemplate == false,
+          "donation menu uses the full-color favicon at 16 points with the requested title")
+    if let donationItem, donationItem.responds(to: NSSelectorFromString("preferredImageVisibility")) {
+        check(donationItem.value(forKey: "preferredImageVisibility") as? Int == 1,
+              "donation menu keeps the favicon visible on macOS 27")
+    }
+    let stopItem = menuItems.first { $0.action == NSSelectorFromString("togglePlayback:") }
+    let pauseItem = menuItems.first { $0.action == NSSelectorFromString("togglePause:") }
+    check(menuItems.filter { !$0.isHidden }.prefix(2).map(\.title) == ["Pause Animation", "Stop Wallpaper"] &&
+          menuItems.allSatisfy { $0.view == nil } && pauseItem?.image != nil && stopItem?.image != nil,
+          "playback commands lead the menu as native items with symbols")
+    let settingsItem = menuItems.first { $0.action == NSSelectorFromString("showOptions:") }
+    check(settingsItem?.title == "Settings…" && settingsItem?.keyEquivalent == "," &&
+          settingsItem?.keyEquivalentModifierMask == .command,
+          "Settings uses the standard macOS label and Command-comma shortcut")
     if let loginIndex = menuItems.firstIndex(where: { $0.title.hasPrefix("Launch at Login") }),
        let syncIndex = menuItems.firstIndex(where: { $0.title == "Sync with Screen Saver" }) {
-        check(syncIndex == loginIndex + 1 && loginIndex > 0 && menuItems[loginIndex - 1].isSeparatorItem &&
+        check(syncIndex == loginIndex + 1 && loginIndex > 1 && menuItems[loginIndex - 1] === settingsItem &&
+              menuItems[loginIndex - 2].isSeparatorItem &&
               syncIndex + 1 < menuItems.count && menuItems[syncIndex + 1].isSeparatorItem,
-              "Sync with Screen Saver sits below Launch at Login between dividers")
+              "settings, login, and screen saver sync form one preference group")
     } else {
         check(false, "menu contains login and screen saver sync controls")
     }
@@ -47,9 +58,9 @@ func wallpaperAppTests() {
 
     let workspace = NSWorkspace.shared.notificationCenter
     wait(0.3)
-    check(NSApp.sendAction(NSSelectorFromString("togglePause:"), to: host, from: nil), "Pause menu action is connected")
-    check(pauseItem?.title == "Resume" && stopItem?.title == "Stop" && pauseItem?.isEnabled == true,
-          "paused menu offers Resume beside Stop")
+    if let pauseItem, let menu = status?.menu { menu.performActionForItem(at: menu.index(of: pauseItem)) }
+    check(pauseItem?.title == "Resume Animation" && stopItem?.title == "Stop Wallpaper" && pauseItem?.isEnabled == true,
+          "native Pause command freezes playback and offers Resume Animation")
     check(originalWindows.allSatisfy { $0.isVisible && ($0.contentView as? MatrixScreenSaverView)?.isAnimating == false },
           "Pause freezes every display without hiding its wallpaper")
     if let source = originalWindows.first?.contentView {
@@ -67,7 +78,7 @@ func wallpaperAppTests() {
     check(desktopWindowCount() == 0 && originalWindows.allSatisfy { ($0.contentView as? MatrixScreenSaverView)?.isAnimating == false },
           "Resume cannot override system sleep")
     workspace.post(name: NSWorkspace.didWakeNotification, object: nil)
-    check(pauseItem?.title == "Pause" && originalWindows.allSatisfy { $0.isVisible && ($0.contentView as? MatrixScreenSaverView)?.isAnimating == true },
+    check(pauseItem?.title == "Pause Animation" && originalWindows.allSatisfy { $0.isVisible && ($0.contentView as? MatrixScreenSaverView)?.isAnimating == true },
           "Resume continues the original views after the system suspension ends")
     workspace.post(name: NSWorkspace.willSleepNotification, object: nil)
     check(desktop.images.values.allSatisfy { $0.url == desktopController.blackImageURL }, "temporary sleep retains black desktops and backups")
@@ -99,7 +110,7 @@ func wallpaperAppTests() {
             wait(0.1)
             first = reader?.frame(displayID: displayID, pointSize: source.bounds.size)
         } while first == nil && Date() < deadline
-        check(first != nil && source.isAnimating && pauseItem?.title == "Resume",
+        check(first != nil && source.isAnimating && pauseItem?.title == "Resume Animation",
               "saver discovery advances the paused scene without clearing manual pause")
         let distributed = DistributedNotificationCenter.default()
         distributed.postNotificationName(Notification.Name("com.apple.screensaver.willstart"), object: nil,
@@ -113,7 +124,7 @@ func wallpaperAppTests() {
               "hidden wallpaper publishes advancing frames for the saver")
         NSApp.sendAction(NSSelectorFromString("togglePause:"), to: host, from: nil)
         NSApp.sendAction(NSSelectorFromString("togglePause:"), to: host, from: nil)
-        check(source.isAnimating && pauseItem?.title == "Resume" && desktopWindowCount() == 0,
+        check(source.isAnimating && pauseItem?.title == "Resume Animation" && desktopWindowCount() == 0,
               "changing manual pause during saver playback preserves the active shared scene")
         let sharedURL = source.shareWallpaperFrames()!
         NSApp.sendAction(NSSelectorFromString("toggleScreenSaverSync:"), to: host, from: nil)
@@ -136,7 +147,7 @@ func wallpaperAppTests() {
         distributed.postNotificationName(Notification.Name("com.apple.screensaver.didstop"), object: nil,
                                          userInfo: nil, deliverImmediately: true)
         wait(0.2)
-        check(!source.isAnimating && pauseItem?.title == "Resume" &&
+        check(!source.isAnimating && pauseItem?.title == "Resume Animation" &&
               Set(originalWindows.filter(\.isVisible).map(ObjectIdentifier.init)) == originalIDs,
               "saver exit immediately reveals the preserved paused wallpaper before its lease expires")
         let frozen = pixels(of: source)
@@ -189,7 +200,7 @@ func wallpaperAppTests() {
         distributed.postNotificationName(Notification.Name("com.apple.screensaver.didstop"), object: nil,
                                          userInfo: nil, deliverImmediately: true)
         wait(0.2)
-        check(!source.isAnimating && pauseItem?.title == "Resume" &&
+        check(!source.isAnimating && pauseItem?.title == "Resume Animation" &&
               Set(NSApp.windows.filter { $0 is DesktopWindow && $0.isVisible }.map(ObjectIdentifier.init)) == originalIDs,
               "saver exit after lease expiry keeps the same wallpaper views paused")
         NSApp.sendAction(NSSelectorFromString("togglePause:"), to: host, from: nil)
@@ -199,8 +210,8 @@ func wallpaperAppTests() {
     workspace.post(name: NSWorkspace.willSleepNotification, object: nil)
 
     check(NSApp.sendAction(NSSelectorFromString("togglePlayback:"), to: host, from: nil), "Stop menu action is connected")
-    check(stopItem?.title == "Start" && pauseItem?.title == "Pause" && pauseItem?.isEnabled == false,
-          "Stop clears manual pause and disables Pause beside Start")
+    check(stopItem?.title == "Start Wallpaper" && pauseItem?.title == "Pause Animation" && pauseItem?.isEnabled == false,
+          "Stop offers Start Wallpaper and leaves Pause Animation visible but disabled")
     NSApp.sendAction(NSSelectorFromString("togglePause:"), to: host, from: nil)
     check(desktop.images["first"]?.url.path == "/original-a.jpg" && desktop.images["second"]?.url.path == "/original-b.jpg",
           "Stop restores desktop images even during suspension")
@@ -264,8 +275,8 @@ private func wallpaperEditingShortcutTests(controller: MatrixScreenSaverOptionsS
     }
     let original = field.stringValue
     let wasEnabled = field.isEnabled
-    let root: NSStackView? = stored("rootStack", in: controller)
-    let tabs = root?.arrangedSubviews.compactMap { $0 as? NSTabView }.first
+    let scroll: NSScrollView? = stored("optionsScrollView", in: controller)
+    let tabs = scroll?.documentView as? NSTabView
     let selectedTab = tabs?.selectedTabViewItem
     tabs?.selectTabViewItem(at: 1)
     defer {
@@ -598,8 +609,8 @@ private func wallpaperIconTests() {
     let menu = NSBitmapImageRep(cgImage: context.makeImage()!)
     let stem = (12..<60).map { menu.colorAt(x: 20, y: $0)! }
     check(menu.colorAt(x: 0, y: 0)!.alphaComponent == 0 &&
-          stem.contains { $0.alphaComponent == 0 } && stem.contains { $0.alphaComponent > 0.9 },
-          "menu icon has transparent background and scanline gaps through the M")
+          stem.allSatisfy { $0.alphaComponent > 0.9 },
+          "menu icon has transparent background and a solid, high-contrast M stem")
     check(stem.allSatisfy { $0.redComponent == $0.greenComponent && $0.greenComponent == $0.blueComponent },
           "menu icon is monochrome for system template tinting")
 }
diff --git a/Tests/MatrixWallpaperTests/main.swift b/Tests/MatrixWallpaperTests/main.swift
index a21b395..fc76176 100644
--- a/Tests/MatrixWallpaperTests/main.swift
+++ b/Tests/MatrixWallpaperTests/main.swift
@@ -26,6 +26,10 @@ func wait(_ seconds: TimeInterval) {
 let app = NSApplication.shared
 app.setActivationPolicy(.accessory)
 app.finishLaunching()
+if CommandLine.arguments.contains("--version-warning-tests") {
+    versionWarningTests()
+    exit(failures == 0 ? EXIT_SUCCESS : EXIT_FAILURE)
+}
 if CommandLine.arguments.contains("--consumer-host") {
     consumerHostTests()
     exit(failures == 0 ? EXIT_SUCCESS : EXIT_FAILURE)
@@ -77,6 +81,7 @@ check(!window.isVisible, "closing removes the desktop window")
 sharedSaverTests()
 sharedCompositionTests()
 wallpaperAppTests()
+versionWarningTests()
 desktopWallpaperTests()
 loginItemTests()
 exit(failures == 0 ? EXIT_SUCCESS : EXIT_FAILURE)
diff --git a/Tools/GenerateWallpaperIcons.swift b/Tools/GenerateWallpaperIcons.swift
index c9eab21..cd1c71c 100644
--- a/Tools/GenerateWallpaperIcons.swift
+++ b/Tools/GenerateWallpaperIcons.swift
@@ -132,11 +132,12 @@ private var bounds = CGRect(x: 0, y: 0, width: 18, height: 18)
 private let context = CGContext(consumer: consumer, mediaBox: &bounds, nil)!
 context.beginPDFPage(nil)
 context.addPath(glyph(in: CGRect(x: 2, y: 2, width: 14, height: 14)))
-context.clip()
+// Solid, slightly heavier strokes keep the small template legible at menu-bar size.
 context.setFillColor(NSColor.black.cgColor)
-for y in stride(from: 2.0, to: 16.0, by: 2.0) {
-    context.fill(CGRect(x: 0, y: y, width: 18, height: 1.35))
-}
+context.setStrokeColor(NSColor.black.cgColor)
+context.setLineWidth(0.45)
+context.setLineJoin(.round)
+context.drawPath(using: .fillStroke)
 context.endPDFPage()
 context.closePDF()
 try (pdf as Data).write(to: resources.appendingPathComponent("MenuBarIcon.pdf"))
diff --git a/build-wallpaper.sh b/build-wallpaper.sh
index 24f6489..6a27134 100755
--- a/build-wallpaper.sh
+++ b/build-wallpaper.sh
@@ -17,6 +17,7 @@ swiftc -O -module-name MatrixWallpaper \
   -framework Foundation -framework AppKit -framework ScreenSaver -framework ServiceManagement \
   "$SOURCE_DIR/TerminalSupport.swift" \
   "$SOURCE_DIR/MatrixScreenSaverOptions.swift" \
+  "$SOURCE_DIR/MatrixVersionStatus.swift" \
   "$SOURCE_DIR/Xorshift64.swift" \
   "$SOURCE_DIR/NeoMessageScene.swift" \
   "$SOURCE_DIR/CmdCaptureScene.swift" \
@@ -39,6 +40,7 @@ cp "$ROOT_DIR/Resources/Wallpaper-Info.plist" "$BUNDLE_DIR/Contents/Info.plist"
 mkdir -p "$BUNDLE_DIR/Contents/Resources/Fonts"
 cp "$ROOT_DIR/Resources/Fonts/"* "$BUNDLE_DIR/Contents/Resources/Fonts/"
 cp "$ROOT_DIR/Resources/WallpaperIcon.icns" "$ROOT_DIR/Resources/MenuBarIcon.pdf" "$BUNDLE_DIR/Contents/Resources/"
+cp "$ROOT_DIR/Resources/BuyMeACoffee.png" "$BUNDLE_DIR/Contents/Resources/BuyMeACoffee.png"
 /usr/libexec/PlistBuddy -c "Set :CFBundleShortVersionString $BUNDLE_VERSION" "$BUNDLE_DIR/Contents/Info.plist"
 /usr/libexec/PlistBuddy -c "Set :CFBundleVersion $BUNDLE_VERSION" "$BUNDLE_DIR/Contents/Info.plist"
 plutil -lint "$BUNDLE_DIR/Contents/Info.plist" >/dev/null
diff --git a/build.sh b/build.sh
index 4db86f1..161b2ed 100755
--- a/build.sh
+++ b/build.sh
@@ -34,6 +34,7 @@ swiftc \
   -framework ScreenSaver \
   "$SOURCE_DIR/TerminalSupport.swift" \
   "$SOURCE_DIR/MatrixScreenSaverOptions.swift" \
+  "$SOURCE_DIR/MatrixVersionStatus.swift" \
   "$SOURCE_DIR/Xorshift64.swift" \
   "$SOURCE_DIR/NeoMessageScene.swift" \
   "$SOURCE_DIR/CmdCaptureScene.swift" \
@@ -47,6 +48,7 @@ swiftc \
 
 cp "$INPUT_RESOURCES_DIR/Info.plist" "$CONTENTS_DIR/Info.plist"
 cp -R "$INPUT_RESOURCES_DIR/Fonts" "$RESOURCES_DIR/Fonts"
+cp "$INPUT_RESOURCES_DIR/BuyMeACoffee.png" "$RESOURCES_DIR/BuyMeACoffee.png"
 for f in Preview.png "Preview@2x.png"; do
   if [[ -f "$INPUT_RESOURCES_DIR/$f" ]]; then
     cp "$INPUT_RESOURCES_DIR/$f" "$RESOURCES_DIR/$f"
diff --git a/docs/development.md b/docs/development.md
new file mode 100644
index 0000000..d084c0b
--- /dev/null
+++ b/docs/development.md
@@ -0,0 +1,50 @@
+# Developer notes
+
+## Wallpaper installer
+
+The installer builds and verifies the app, gracefully quits running copies before
+replacement, and retains preferences. It does not launch the app or enable login startup.
+It migrates a signed `MatrixWallpaper.app` with the matching bundle ID to
+`Matrix Wallpaper.app`, restoring the previous installation if replacement fails.
+Unrelated bundles and symlinks at the old path are left alone. The executable remains
+`MatrixWallpaper` and the bundle ID remains `dev.patsch.MatrixWallpaper`.
+
+## Screen saver synchronization
+
+When MatrixScreenSaver is installed in `~/Library/Screen Savers` or `/Library/Screen Savers`,
+the wallpaper menu shows **Sync with Screen Saver**. It is checked by default: the saver
+shares the wallpaper's animation. Uncheck it to let the saver animate independently.
+The choice survives app restarts and saver reinstallation; opening the menu refreshes
+installation detection. This does not change visual options or synchronization between monitors.
+
+## Component version checks
+
+If Matrix Wallpaper and Matrix Screen Saver have different release versions, an error
+appears above the options tabs, on the menu-bar icon, and at the top of its menu.
+The wallpaper also shows an alert once per launch. Matrix playback is blocked in both
+components: a yellow warning triangle moves slowly over a black screen instead. With Reduce
+Motion enabled, the symbol stays still. Settings remain editable. Choose **View Releases…**
+and install matching versions to resume playback.
+Checks refresh when opening settings or the menu, and approximately once a minute during
+playback. A missing companion is not a mismatch; unreadable version information
+is explained in settings. Checks compare the loaded host with installed companion bundles,
+so another process may still need restarting after an update. Older releases do not gain
+these warnings until they are updated.
+
+## Desktop wallpaper lifecycle
+
+While Matrix Wallpaper runs, it saves each display's desktop image and display options,
+then sets the underlying wallpaper to plain black. The menu starts with **Pause Animation**
+and **Stop Wallpaper**. **Pause Animation** freezes the visible frame; **Resume Animation** continues the scene.
+Pausing is session-only and does not persist across launches. With **Sync with Screen Saver**
+enabled, the saver temporarily advances the shared scene even while the wallpaper is paused.
+When the saver exits, the wallpaper pauses again at the updated scene. **Stop Wallpaper** and
+**Quit Matrix Wallpaper** restore the original wallpaper settings. Temporary pauses
+and animation restarts keep the original backup.
+If you choose a different wallpaper while Matrix runs, that newer choice is preserved.
+
+Backups are stored in `~/Library/Application Support/MatrixWallpaper/DesktopWallpaper/`.
+After a crash or force-quit, reopen Matrix Wallpaper and choose **Stop Wallpaper** to restore the desktop.
+Disconnected displays and failed restores keep their backups for a later retry.
+Exact restoration is supported for static images; macOS's public API cannot preserve every
+dynamic/aerial wallpaper, rotating collection, or separate Space configuration.
diff --git a/docs/plans/2026-11-10-1812-project-roadmap-plan.md b/docs/plans/2026-11-10-1812-project-roadmap-plan.md
new file mode 100644
index 0000000..500e29b
--- /dev/null
+++ b/docs/plans/2026-11-10-1812-project-roadmap-plan.md
@@ -0,0 +1,67 @@
+# Matrix Screen Saver and Wallpaper — Project Roadmap
+Created: 2026-11-10
+
+This roadmap records future work for the native macOS screen saver and animated wallpaper. It does not authorize implementation or set release dates. Feature-specific implementation plans remain in this directory.
+
+## Current foundation
+
+- Native Swift/AppKit screen saver and wallpaper app share the Matrix animation and options.
+- `NativeMatrixRenderer.swift` supplies the falling glyphs and intro scenes.
+- `SharedWallpaperCompositor.swift` already uses Metal and Core Image for GPU-assisted wallpaper compositing. This is not a full 3D scene renderer.
+
+## Planned: GPU-accelerated 3D Matrix hallway scene
+
+### Goal
+
+Render the scene from *The Matrix* in which three Agents stand in a hallway aiming their guns toward the camera. Use the project's own animated falling glyphs as textures across the walls and throughout the scene, rather than relying on a prerecorded video or baked-in code texture.
+
+The goal is a real 3D scene with depth and perspective, available in both the screen saver and animated wallpaper. Keep the existing 2D rain available.
+
+### Milestones
+
+1. **Find a suitable 3D model.**
+   - Look for the complete hallway scene with all three Agents in the intended poses and camera composition.
+   - Check model quality, UV mapping, material separation, and suitability for real-time rendering.
+   - Verify permission to modify and redistribute the model and its textures with both products. Record the source, author, license, and required attribution; a downloadable model is not automatically redistributable.
+   - If no suitable complete scene is available, bring back options for assembling licensed assets or commissioning a model before changing the intended scene or spending money.
+   - Deliverable: a model shortlist with reference images, licensing evidence, and an asset recommendation. No model has been selected yet.
+
+2. **Validate native, GPU-accelerated 3D rendering.**
+   - Evaluate a native macOS rendering path, taking the existing Metal integration into account. Choose the framework after checking compatibility with both the `.saver` host and wallpaper app.
+   - Start with a small scene to verify model loading, camera projection, lighting, depth, and rendering at display backing resolution.
+   - Measure frame time, GPU/CPU use, memory, and energy impact on representative supported hardware and multiple displays before setting performance targets.
+   - Deliverable: a rendering proof of concept and a technical implementation plan, not a rewrite of the existing renderer.
+
+3. **Use our falling glyphs as live scene textures.**
+   - Reuse the project's glyph artwork and animation rather than substituting someone else's Matrix-code effect.
+   - Map the animated glyphs onto the hallway walls, floor, ceiling, and Agent/model surfaces to achieve the code-covered scene. Check orientation, scale, seams, and readability on each surface.
+   - The glyphs must follow the 3D surfaces and perspective, not act as a flat overlay in front of the camera.
+   - Reuse textures and rendering resources where possible; measure the cost of updating the live glyph textures.
+   - Deliverable: the chosen model rendered with the project's animated glyph textures.
+
+4. **Integrate and verify the hallway scene.**
+   - Add the scene to the shared playback/options flow without removing existing rain or intro scenes.
+   - Preserve Start, Stop, Pause, Quit, sleep/wake, display synchronization, and desktop-wallpaper restoration.
+   - Keep playback local after installation; bundle approved assets rather than fetching models at runtime.
+   - Verify the scene in the actual screen saver host, preview host, and wallpaper app, including display changes and resource cleanup.
+   - Deliverable: a user-selectable scene with visual, lifecycle, and performance checks.
+
+### Acceptance criteria
+
+- Three Agents stand in the hallway aiming toward the camera, with composition reviewed against the intended movie scene.
+- Geometry, depth, lighting, and animated materials are rendered using hardware-accelerated 3D graphics.
+- The project's falling glyphs animate across scene surfaces, including walls and other visible geometry.
+- Both products render the scene without breaking existing playback, synchronization, or desktop restoration.
+- All bundled models and textures have documented modification and redistribution rights.
+- Frame-rate and resource-use targets are agreed from the rendering measurements and verified before release.
+
+### Decisions still open
+
+- Exact movie reference frame and model source.
+- Native 3D framework, asset format, and any necessary model conversion.
+- Supported-hardware performance budget and behavior when the 3D rendering path is unavailable.
+- Whether the first version keeps the camera and Agent poses fixed or adds motion. Motion beyond the falling glyphs is not yet specified.
+
+## Next planning step
+
+Source the model candidates and confirm the reference composition. Use those findings and the rendering proof of concept to write a bounded implementation plan before starting production changes.
diff --git a/docs/wallpaper-menubar.jpg b/docs/wallpaper-menubar.jpg
index df079e1..b6ea5dd 100644
Binary files a/docs/wallpaper-menubar.jpg and b/docs/wallpaper-menubar.jpg differ
diff --git a/tests.sh b/tests.sh
index 3a04d22..14d4639 100755
--- a/tests.sh
+++ b/tests.sh
@@ -17,6 +17,7 @@ swiftc \
   -framework AppKit \
   -framework ScreenSaver \
   "$SRC/TerminalSupport.swift" \
+  "$SRC/MatrixVersionStatus.swift" \
   "$SRC/Xorshift64.swift" \
   "$SRC/NeoMessageScene.swift" \
   "$SRC/CmdCaptureScene.swift" \
@@ -32,6 +33,7 @@ swiftc \
   "$TESTS/NativeMatrixRendererTests.swift" \
   "$TESTS/WallpaperPlaybackStateTests.swift" \
   "$TESTS/SharedWallpaperFrameTests.swift" \
+  "$TESTS/MatrixVersionStatusTests.swift" \
   "$TESTS/main.swift" \
   -o "$TEST_BIN"
 
diff --git a/wallpaper-tests.sh b/wallpaper-tests.sh
index 2f833fa..069f016 100755
--- a/wallpaper-tests.sh
+++ b/wallpaper-tests.sh
@@ -13,6 +13,7 @@ HOST_DIR="$TEST_CONTENTS/MacOS"
 TEST_BIN="$HOST_DIR/matrix-wallpaper-tests"
 mkdir -p "$HOST_DIR" "$TEST_CONTENTS/Resources"
 cp -R "$ROOT_DIR/Resources/Fonts" "$TEST_CONTENTS/Resources/Fonts"
+cp "$ROOT_DIR/Resources/BuyMeACoffee.png" "$TEST_CONTENTS/Resources/BuyMeACoffee.png"
 
 OPTIMIZATION="-Onone"
 if [[ "${1:-}" == "--gpu-composition-benchmark" || "${1:-}" == "--composition-benchmark" ]]; then
@@ -22,6 +23,7 @@ fi
 swiftc "$OPTIMIZATION" -framework Foundation -framework AppKit -framework ScreenSaver -framework ServiceManagement \
   "$SOURCE_DIR/TerminalSupport.swift" \
   "$SOURCE_DIR/MatrixScreenSaverOptions.swift" \
+  "$SOURCE_DIR/MatrixVersionStatus.swift" \
   "$SOURCE_DIR/Xorshift64.swift" \
   "$SOURCE_DIR/NeoMessageScene.swift" \
   "$SOURCE_DIR/CmdCaptureScene.swift" \
@@ -42,12 +44,13 @@ swiftc "$OPTIMIZATION" -framework Foundation -framework AppKit -framework Screen
   "$TEST_DIR/SharedCompositionTests.swift" \
   "$TEST_DIR/GPUCompositionTests.swift" \
   "$TEST_DIR/WallpaperAppTests.swift" \
+  "$TEST_DIR/VersionWarningTests.swift" \
   "$TEST_DIR/LoginItemTests.swift" \
   "$TEST_DIR/DesktopWallpaperTests.swift" \
   "$TEST_DIR/main.swift" \
   -o "$TEST_BIN"
 
-if [[ "${1:-}" == "--composition-benchmark" || "${1:-}" == "--composition-tests" || "${1:-}" == "--gpu-composition-tests" || "${1:-}" == "--gpu-composition-benchmark" ]]; then
+if [[ "${1:-}" == "--composition-benchmark" || "${1:-}" == "--composition-tests" || "${1:-}" == "--gpu-composition-tests" || "${1:-}" == "--gpu-composition-benchmark" || "${1:-}" == "--version-warning-tests" ]]; then
   "$TEST_BIN" "$1"
   exit
 fi