Ariver
2026-06-12 a4af5d51e8fbb8a0e53f98aa9f9e238536aaba24
C1.source/Sources/Aligner/QuickSwitchRootView.swift
@@ -22,11 +22,17 @@
    private let waterfallLayer = CALayer()
    private let waterfallContentLayer = CALayer()
    private lazy var closeConfirmationLayers = makeCloseConfirmationLayers()
    private let closeFeedbackLayer = CALayer()
    private let closeFeedbackTextLayer = CATextLayer()
    private let settingsButtonLayer = CALayer()
    private let settingsButtonIconLayer = CALayer()
    private let settingsButtonFallbackTextLayer = CATextLayer()
    private let appIconProvider: any AppIconProviderProtocol = WorkspaceAppIconProvider()
    private let skeletonThumbnailProvider = NativeSkeletonThumbnailProvider(size: NSSize(width: 160, height: 96))
    private var screenshotSourcesByWindowID: [UInt32: ScreenshotResolutionSource] = [:]
    private var screenshotSkippedReasonsByWindowID: [UInt32: String] = [:]
    private var currentViewModel: QuickSwitchViewModel?
    private var spaceLaneDisplayGroups: [SpaceLaneDisplayGroupLayers] = []
    private var spaceLaneSegments: [SpaceLaneSegmentLayers] = []
    private var spaceLaneContentWidth: CGFloat = 0
    private var spaceLaneScrollOffset: CGFloat = 0
@@ -40,16 +46,25 @@
    private var hoveredSpaceID: UInt64?
    private var hoveredCloseTarget: CloseTarget?
    private var pendingCloseTarget: CloseTarget?
    private var pendingCloseRequest: QuickSwitchCloseRequest?
    private var pendingCloseOptOut = false
    private var closeConfirmationArrowEdge: CloseConfirmationArrowEdge?
    private var closeConfirmationRequired = true
    private var closeFeedback: CloseFeedback?
    private var closeFeedbackHideTask: Task<Void, Never>?
    private var isSettingsButtonHovered = false
    private var hoverTarget: HoverTarget = .none
    private var hoverTargetSource: HoverTargetSource = .event
    private var hoveredSpaceLaneID: UInt64?
    private var focusedSpaceID: UInt64?
    private var debugHoveredAppGroupIndex: Int?
    private var waterfallColumns: [WaterfallColumnLayers] = []
    private var waterfallViewMode: QuickSwitchWaterfallViewMode = .verticalColumns
    private var waterfallContentWidth: CGFloat = 0
    private var waterfallScrollOffset: CGFloat = 0
    private var waterfallColumnScrollOffsets: [Int: CGFloat] = [:]
    private var horizontalMasonryContentHeight: CGFloat = 0
    private var horizontalMasonryScrollOffset: CGFloat = 0
    private var currentSelection: QuickSwitchSelection?
    private var columnSelectionHistory: [Int: Int] = [:]
    private var keyboardCommandsApplied: [String] = []
@@ -70,8 +85,17 @@
    private var keyboardResponseLatencyMilliseconds: [Double] = []
    private var mouseResponseLatencyMilliseconds: [Double] = []
    private var hoverResponseLatencyMilliseconds: [Double] = []
    private var lastProjectionTransitionMovedLayerCount = 0
    private var lastProjectionTransitionFadeInLayerCount = 0
    private var lastProjectionTransitionFadeOutLayerCount = 0
    private var lastProjectionTransitionDurationMilliseconds: Double = 0
    private var suppressEventInput = false
    private var suppressEventBackgroundClicks = false
    var onEscape: (() -> Void)?
    var onCommitSelection: ((QuickSwitchSelection, QuickSwitchCommitSource) -> Void)?
    var onSpaceLaneClick: ((UInt64, Int) -> Void)?
    var onBackgroundClick: (() -> Bool)?
    var onOpenSettings: (() -> Void)?
    var onRequestClose: ((QuickSwitchCloseRequest) -> Void)?
    var onCloseConfirmationDisabled: (() -> Void)?
@@ -108,9 +132,92 @@
        let cancelButtonTextLayer: CATextLayer
    }
    private struct CloseFeedback: Equatable, Sendable {
        enum Kind: String, Sendable {
            case progress
            case failure
        }
        let kind: Kind
        let message: String
        let targetKind: String
        let appGroupIndex: Int
        let windowID: UInt32?
    }
    private enum CloseConfirmationArrowEdge: String {
        case left
        case right
    }
    private enum HoverTarget: Equatable {
        case none
        case space(UInt64)
        case app(Int)
        case window(appGroupIndex: Int, windowID: UInt32, spaceID: UInt64?)
        var kindDescription: String {
            switch self {
            case .none:
                return "none"
            case .space:
                return "space"
            case .app:
                return "app"
            case .window:
                return "window"
            }
        }
        var appGroupIndex: Int? {
            switch self {
            case .app(let appGroupIndex):
                return appGroupIndex
            case .window(let appGroupIndex, _, _):
                return appGroupIndex
            case .none, .space:
                return nil
            }
        }
        var windowID: UInt32? {
            switch self {
            case .window(_, let windowID, _):
                return windowID
            case .none, .space, .app:
                return nil
            }
        }
        var spaceID: UInt64? {
            switch self {
            case .space(let spaceID):
                return spaceID
            case .window(_, _, let spaceID):
                return spaceID
            case .none, .app:
                return nil
            }
        }
        var spaceLaneID: UInt64? {
            guard case .space(let spaceID) = self else { return nil }
            return spaceID
        }
        var shouldAlignWaterfallWithAppShelf: Bool {
            switch self {
            case .app:
                return true
            case .none, .space, .window:
                return false
            }
        }
    }
    private enum HoverTargetSource: String {
        case event
        case debug
    }
    private struct SpaceLaneSegmentLayers {
@@ -119,8 +226,15 @@
        let labelLayer: CATextLayer
        let countLayer: CATextLayer
        let appLayer: CATextLayer
        let splitAppLayers: [CATextLayer]
        let windowBlocks: [CALayer]
        let fullscreenMarkerLayer: CALayer?
    }
    private struct SpaceLaneDisplayGroupLayers {
        let display: QuickSwitchDisplayViewModel
        let containerLayer: CALayer
        let segments: [SpaceLaneSegmentLayers]
    }
    private struct AppShelfItemLayers {
@@ -161,6 +275,22 @@
        let closeButton: CloseButtonLayers
    }
    private struct ProjectionLayerSnapshot {
        let layer: CALayer
        let frame: CGRect
    }
    private struct ProjectionColumnSnapshot {
        let layer: CALayer
        let frame: CGRect
        let cardsByWindowID: [UInt32: ProjectionLayerSnapshot]
    }
    private struct ProjectionTransitionSnapshot {
        let appShelfItemsByAppGroupIndex: [Int: ProjectionLayerSnapshot]
        let waterfallColumnsByAppGroupIndex: [Int: ProjectionColumnSnapshot]
    }
    private enum AppShelfMetrics {
        static let normalIconSize: CGFloat = 56
        static let hoverIconSize: CGFloat = 68
@@ -184,11 +314,25 @@
        static let columnWidth: CGFloat = 252
        static let columnMinWidth: CGFloat = 220
        static let columnMaxWidth: CGFloat = 292
        static let columnPadding: CGFloat = 12
        static let contentHorizontalPadding: CGFloat = 0
        static let columnHorizontalPadding: CGFloat = 0
        static let columnVerticalPadding: CGFloat = 0
        static let columnHeaderTextInset: CGFloat = 12
        static let headerHeight: CGFloat = 34
        static let cardHeight: CGFloat = 138
        static let cardGap: CGFloat = 12
        static let revealPadding: CGFloat = 24
        static let horizontalRevealPadding: CGFloat = 0
    }
    private enum HorizontalMasonryMetrics {
        static let horizontalPadding: CGFloat = 12
        static let verticalPadding: CGFloat = 0
        static let horizontalGap: CGFloat = 16
        static let verticalGap: CGFloat = WaterfallMetrics.cardGap
        static let cardMinWidth: CGFloat = 220
        static let cardMaxWidth: CGFloat = 320
        static let cardHeight: CGFloat = WaterfallMetrics.cardHeight
    }
    private enum WaterfallHorizontalIntent {
@@ -200,6 +344,16 @@
        static let tolerance: CGFloat = 1
        static let animationDuration: CFTimeInterval = 0.18
        static let animationTimingName = CAMediaTimingFunctionName.easeOut
    }
    private enum SpaceLaneMetrics {
        static let horizontalPadding: CGFloat = 0
        static let groupGap: CGFloat = 36
        static let groupHorizontalPadding: CGFloat = 24
        static let groupVerticalPadding: CGFloat = 6
        static let segmentGap: CGFloat = 12
        static let segmentMinWidth: CGFloat = 96
        static let segmentMaxWidth: CGFloat = 150
    }
    override init(frame frameRect: NSRect) {
@@ -231,7 +385,7 @@
        let trackingArea = NSTrackingArea(
            rect: bounds,
            options: [.activeInKeyWindow, .mouseMoved, .mouseEnteredAndExited, .inVisibleRect],
            options: [.activeAlways, .mouseMoved, .mouseEnteredAndExited, .inVisibleRect],
            owner: self,
            userInfo: nil
        )
@@ -247,6 +401,13 @@
    }
    override func keyDown(with event: NSEvent) {
        if suppressEventInput {
            DevelopmentDiagnostics.log("quickSwitch.view.keyDown.ignoredForDebugSequence", [
                "keyCode": event.keyCode
            ])
            return
        }
        switch event.keyCode {
        case TriggerKeyCode.escape where Self.shouldDismissOnEscape(event):
            onEscape?()
@@ -268,6 +429,8 @@
    }
    override func scrollWheel(with event: NSEvent) {
        refreshHoverTarget(at: event.locationInWindow)
        let dominantDelta = abs(event.scrollingDeltaX) >= abs(event.scrollingDeltaY)
            ? event.scrollingDeltaX
            : event.scrollingDeltaY
@@ -287,6 +450,15 @@
        }
        if shouldScrollWaterfall(for: event) {
            if isHorizontalMasonryMode {
                let currentOffset = horizontalMasonryScrollOffset
                horizontalMasonryScrollOffset = clampedHorizontalMasonryOffset(
                    currentOffset - event.scrollingDeltaY
                )
                needsLayout = true
                return
            }
            if abs(event.scrollingDeltaX) >= abs(event.scrollingDeltaY), waterfallAlignmentScrollable {
                waterfallScrollOffset = clampedWaterfallAlignmentOffset(waterfallScrollOffset - event.scrollingDeltaX)
                needsLayout = true
@@ -313,52 +485,48 @@
    override func mouseMoved(with event: NSEvent) {
        guard debugHoveredAppGroupIndex == nil else { return }
        let settingsHovered = settingsButtonContains(windowLocation: event.locationInWindow)
        if isSettingsButtonHovered != settingsHovered {
            isSettingsButtonHovered = settingsHovered
            needsLayout = true
        }
        if settingsHovered {
            hoveredCloseTarget = nil
            setHoverTarget(.none)
            return
        }
        let closeTarget = closeButtonTarget(at: event.locationInWindow)
        if hoveredCloseTarget != closeTarget {
            hoveredCloseTarget = closeTarget
            needsLayout = true
        }
        if let segment = spaceLaneSegment(at: event.locationInWindow) {
            hoverSpaceLaneSegment(segment)
            return
        }
        if let card = waterfallCard(at: event.locationInWindow) {
            hoveredSpaceLaneID = nil
            updateHoverState(
                appGroupIndex: card.item.appGroupIndex,
                windowID: card.item.window.id,
                spaceID: card.item.primarySpaceID
            )
            return
        }
        if let item = appShelfItem(at: event.locationInWindow) {
            hoveredSpaceLaneID = nil
            updateHoverState(
                appGroupIndex: item.item.appGroupIndex,
                windowID: nil,
                spaceID: nil,
                alignsWaterfallWithAppShelf: true
            )
            return
        }
        hoveredSpaceLaneID = nil
        hoveredCloseTarget = nil
        updateHoverState(appGroupIndex: nil, windowID: nil, spaceID: nil)
        refreshHoverTarget(at: event.locationInWindow)
    }
    override func mouseExited(with event: NSEvent) {
        guard debugHoveredAppGroupIndex == nil else { return }
        hoveredSpaceLaneID = nil
        isSettingsButtonHovered = false
        hoveredCloseTarget = nil
        updateHoverState(appGroupIndex: nil, windowID: nil, spaceID: nil)
        setHoverTarget(.none)
    }
    override func mouseDown(with event: NSEvent) {
        if suppressEventInput {
            DevelopmentDiagnostics.log("quickSwitch.view.mouseDown.ignoredForDebugSequence", [
                "x": event.locationInWindow.x,
                "y": event.locationInWindow.y,
                "bounds": NSStringFromRect(bounds)
            ])
            return
        }
        if handleCloseConfirmationMouseDown(at: event.locationInWindow) {
            return
        }
        if settingsButtonContains(windowLocation: event.locationInWindow) {
            clickSettingsButton(source: "mouse")
            return
        }
@@ -373,7 +541,7 @@
        }
        if let segment = spaceLaneSegment(at: event.locationInWindow) {
            clickSpaceLaneSegment(segment)
            clickSpaceLaneSegment(segment, clickCount: max(1, event.clickCount))
            return
        }
@@ -387,15 +555,16 @@
            "y": event.locationInWindow.y,
            "bounds": NSStringFromRect(bounds)
        ])
        if !suppressEventBackgroundClicks, onBackgroundClick?() == true {
            return
        }
        super.mouseDown(with: event)
    }
    func setDebugHoveredAppGroupIndex(_ index: Int?) {
        debugHoveredAppGroupIndex = index
        setHoverTarget(.none, source: .debug)
        hoveredAppGroupIndex = index
        hoveredWindowID = nil
        hoveredSpaceID = nil
        hoveredSpaceLaneID = nil
        needsLayout = true
    }
@@ -432,6 +601,15 @@
        }
    }
    func setSuppressEventBackgroundClicks(_ suppressed: Bool) {
        suppressEventBackgroundClicks = suppressed
    }
    func setSuppressEventInput(_ suppressed: Bool) {
        suppressEventInput = suppressed
        suppressEventBackgroundClicks = suppressed
    }
    func beginPerformanceFirstFrameMeasurement() {
        firstFrameMeasurementStart = CACurrentMediaTime()
    }
@@ -457,10 +635,58 @@
        closeConfirmationRequired = required
        if !required {
            pendingCloseTarget = nil
            pendingCloseRequest = nil
            pendingCloseOptOut = false
            closeConfirmationLayers.containerLayer.isHidden = true
            closeConfirmationArrowEdge = nil
        }
        needsLayout = true
    }
    func setWaterfallViewMode(_ mode: QuickSwitchWaterfallViewMode) {
        guard waterfallViewMode != mode else { return }
        waterfallViewMode = mode
        waterfallScrollOffset = 0
        waterfallColumnScrollOffsets = [:]
        horizontalMasonryScrollOffset = 0
        horizontalMasonryContentHeight = 0
        needsLayout = true
    }
    func showCloseProgress(for request: QuickSwitchCloseRequest) {
        setCloseFeedback(
            CloseFeedback(
                kind: .progress,
                message: "正在关闭...",
                targetKind: request.kindDescription,
                appGroupIndex: request.appGroupIndex,
                windowID: request.windowID
            ),
            autoHideAfter: nil
        )
    }
    func showCloseFailure(message: String, for request: QuickSwitchCloseRequest) {
        setCloseFeedback(
            CloseFeedback(
                kind: .failure,
                message: message,
                targetKind: request.kindDescription,
                appGroupIndex: request.appGroupIndex,
                windowID: request.windowID
            ),
            autoHideAfter: 2.75
        )
    }
    func clearCloseFeedback() {
        closeFeedbackHideTask?.cancel()
        closeFeedbackHideTask = nil
        closeFeedback = nil
        closeFeedbackLayer.isHidden = true
        closeFeedbackLayer.opacity = 0
        closeFeedbackTextLayer.string = ""
        needsLayout = true
    }
@@ -471,7 +697,9 @@
        guard let card = waterfallCardsByWindowID()[windowID] else { return }
        card.thumbnailLayer.contents = resolution.image
        if case .realScreenshot = resolution.source {
            card.shineLayer.opacity = card.item.window.id == effectiveSelection?.windowID ? 1 : 0
            let isSelected = card.item.window.id == effectiveSelection?.windowID
            let isHovered = card.item.window.id == hoveredWindowID
            card.shineLayer.opacity = shouldShowSelectedVisual(isSelected: isSelected, isHovered: isHovered) ? 1 : 0
        }
        needsLayout = true
    }
@@ -488,39 +716,77 @@
        }
    }
    func effectiveSelectionForProjection() -> QuickSwitchSelection? {
        effectiveSelection
    }
    func apply(viewModel: QuickSwitchViewModel?) {
        apply(viewModel: viewModel, preservingInteractionState: false, animatedProjection: false)
    }
    func applyProjected(viewModel: QuickSwitchViewModel?) {
        apply(viewModel: viewModel, preservingInteractionState: true, animatedProjection: true)
    }
    private func apply(
        viewModel: QuickSwitchViewModel?,
        preservingInteractionState: Bool,
        animatedProjection: Bool
    ) {
        let transitionSnapshot = animatedProjection ? captureProjectionTransitionSnapshot() : nil
        if !animatedProjection {
            resetProjectionTransitionReport()
        }
        currentViewModel = viewModel
        screenshotSourcesByWindowID = [:]
        screenshotSkippedReasonsByWindowID = [:]
        currentSelection = viewModel?.initialSelection
        columnSelectionHistory = [:]
        keyboardCommandsApplied = []
        lastKeyboardCommand = nil
        tabIgnoredCount = 0
        lastCommittedSelection = nil
        lastCommitSource = nil
        mouseCommandsApplied = []
        lastMouseCommand = nil
        lastClickedAppGroupIndex = nil
        lastAppShelfClickChangedSelection = nil
        lastClickedWindowID = nil
        lastSpaceFocusedAppGroupIndex = nil
        lastSpaceLaneClickSpaceID = nil
        lastAppShelfScrollSyncedAppGroupIndex = nil
        hoveredWindowID = nil
        hoveredSpaceID = nil
        hoveredCloseTarget = nil
        pendingCloseTarget = nil
        pendingCloseOptOut = false
        closeConfirmationLayers.containerLayer.isHidden = true
        closeConfirmationArrowEdge = nil
        hoveredSpaceLaneID = nil
        focusedSpaceID = nil
        if debugHoveredAppGroupIndex == nil {
            hoveredAppGroupIndex = nil
        if preservingInteractionState {
            currentSelection = validSelection(currentSelection, in: viewModel) ?? viewModel?.initialSelection
            columnSelectionHistory = columnSelectionHistory.filter { appGroupIndex, _ in
                viewModel?.waterfallColumns.contains { $0.appGroupIndex == appGroupIndex } == true
            }
            if let currentSelection {
                columnSelectionHistory[currentSelection.appGroupIndex] = currentSelection.windowIndex
            }
            hoveredCloseTarget = nil
            pendingCloseTarget = nil
            pendingCloseRequest = nil
            pendingCloseOptOut = false
            closeConfirmationLayers.containerLayer.isHidden = true
            closeConfirmationArrowEdge = nil
        } else {
            screenshotSourcesByWindowID = [:]
            screenshotSkippedReasonsByWindowID = [:]
            currentSelection = viewModel?.initialSelection
            columnSelectionHistory = [:]
            keyboardCommandsApplied = []
            lastKeyboardCommand = nil
            tabIgnoredCount = 0
            lastCommittedSelection = nil
            lastCommitSource = nil
            mouseCommandsApplied = []
            lastMouseCommand = nil
            lastClickedAppGroupIndex = nil
            lastAppShelfClickChangedSelection = nil
            lastClickedWindowID = nil
            lastSpaceFocusedAppGroupIndex = nil
            lastSpaceLaneClickSpaceID = nil
            lastAppShelfScrollSyncedAppGroupIndex = nil
            waterfallScrollOffset = 0
            waterfallColumnScrollOffsets = [:]
            horizontalMasonryScrollOffset = 0
            horizontalMasonryContentHeight = 0
            focusedSpaceID = nil
            hoveredCloseTarget = nil
            pendingCloseTarget = nil
            pendingCloseRequest = nil
            pendingCloseOptOut = false
            closeConfirmationLayers.containerLayer.isHidden = true
            closeConfirmationArrowEdge = nil
            clearCloseFeedback()
            setHoverTarget(.none)
            hoveredAppGroupIndex = debugHoveredAppGroupIndex
        }
        if let currentSelection {
            columnSelectionHistory[currentSelection.appGroupIndex] = currentSelection.windowIndex
        }
@@ -530,6 +796,250 @@
        needsLayout = true
        ensureCurrentSelectionVisible(horizontalIntent: .alignWithAppShelf(animated: false))
        needsLayout = true
        if animatedProjection, let transitionSnapshot {
            layoutSubtreeIfNeeded()
            applyProjectionTransitionAnimations(from: transitionSnapshot)
        }
    }
    private func validSelection(
        _ selection: QuickSwitchSelection?,
        in viewModel: QuickSwitchViewModel?
    ) -> QuickSwitchSelection? {
        guard let selection, let viewModel else { return nil }
        for column in viewModel.waterfallColumns {
            if let card = column.windows.first(where: { $0.window.id == selection.windowID }) {
                return QuickSwitchSelection(
                    appGroupIndex: card.appGroupIndex,
                    windowIndex: card.windowIndex,
                    windowID: card.window.id
                )
            }
        }
        return nil
    }
    private func captureProjectionTransitionSnapshot() -> ProjectionTransitionSnapshot {
        ProjectionTransitionSnapshot(
            appShelfItemsByAppGroupIndex: Dictionary(
                uniqueKeysWithValues: appShelfItems.map { item in
                    (
                        item.item.appGroupIndex,
                        ProjectionLayerSnapshot(
                            layer: item.containerLayer,
                            frame: item.containerLayer.frame
                        )
                    )
                }
            ),
            waterfallColumnsByAppGroupIndex: Dictionary(
                uniqueKeysWithValues: waterfallColumns.map { column in
                    (
                        column.column.appGroupIndex,
                        ProjectionColumnSnapshot(
                            layer: column.containerLayer,
                            frame: column.containerLayer.frame,
                            cardsByWindowID: Dictionary(
                                uniqueKeysWithValues: column.cards.map { card in
                                    (
                                        card.item.window.id,
                                        ProjectionLayerSnapshot(
                                            layer: card.containerLayer,
                                            frame: card.containerLayer.frame
                                        )
                                    )
                                }
                            )
                        )
                    )
                }
            )
        )
    }
    private func applyProjectionTransitionAnimations(from snapshot: ProjectionTransitionSnapshot) {
        let reduceMotion = NSWorkspace.shared.accessibilityDisplayShouldReduceMotion
        let duration: CFTimeInterval = reduceMotion ? 0.12 : 0.21
        let timing = CAMediaTimingFunction(name: reduceMotion ? .linear : .easeOut)
        var movedLayerCount = 0
        var fadeInLayerCount = 0
        var fadeOutLayerCount = 0
        for item in appShelfItems {
            guard let oldSnapshot = snapshot.appShelfItemsByAppGroupIndex[item.item.appGroupIndex] else {
                if addFadeInAnimation(to: item.containerLayer, duration: duration, timing: timing) {
                    fadeInLayerCount += 1
                }
                continue
            }
            if addPositionAnimation(to: item.containerLayer, from: oldSnapshot.frame, duration: duration, timing: timing) {
                movedLayerCount += 1
            }
        }
        let visibleAppGroupIndexes = Set(appShelfItems.map(\.item.appGroupIndex))
        for (appGroupIndex, oldSnapshot) in snapshot.appShelfItemsByAppGroupIndex
            where !visibleAppGroupIndexes.contains(appGroupIndex) {
            if addFadeOutSnapshot(
                oldSnapshot,
                to: appShelfContentLayer,
                frame: oldSnapshot.frame,
                duration: duration,
                timing: timing
            ) {
                fadeOutLayerCount += 1
            }
        }
        for column in waterfallColumns {
            guard let oldSnapshot = snapshot.waterfallColumnsByAppGroupIndex[column.column.appGroupIndex] else {
                if addFadeInAnimation(to: column.containerLayer, duration: duration, timing: timing) {
                    fadeInLayerCount += 1
                }
                continue
            }
            if addPositionAnimation(to: column.containerLayer, from: oldSnapshot.frame, duration: duration, timing: timing) {
                movedLayerCount += 1
            }
            for card in column.cards {
                guard let oldCardSnapshot = oldSnapshot.cardsByWindowID[card.item.window.id] else {
                    if addFadeInAnimation(to: card.containerLayer, duration: duration, timing: timing) {
                        fadeInLayerCount += 1
                    }
                    continue
                }
                if addPositionAnimation(to: card.containerLayer, from: oldCardSnapshot.frame, duration: duration, timing: timing) {
                    movedLayerCount += 1
                }
            }
        }
        let visibleColumnsByAppGroupIndex = Dictionary(
            uniqueKeysWithValues: waterfallColumns.map { ($0.column.appGroupIndex, $0) }
        )
        for (appGroupIndex, oldSnapshot) in snapshot.waterfallColumnsByAppGroupIndex {
            guard let visibleColumn = visibleColumnsByAppGroupIndex[appGroupIndex] else {
                if addFadeOutSnapshot(
                    ProjectionLayerSnapshot(layer: oldSnapshot.layer, frame: oldSnapshot.frame),
                    to: waterfallContentLayer,
                    frame: oldSnapshot.frame,
                    duration: duration,
                    timing: timing
                ) {
                    fadeOutLayerCount += 1
                }
                continue
            }
            let visibleWindowIDs = Set(visibleColumn.cards.map(\.item.window.id))
            for (windowID, oldCardSnapshot) in oldSnapshot.cardsByWindowID
                where !visibleWindowIDs.contains(windowID) {
                let absoluteFrame = oldCardSnapshot.frame.offsetBy(
                    dx: oldSnapshot.frame.minX,
                    dy: oldSnapshot.frame.minY
                )
                if addFadeOutSnapshot(
                    oldCardSnapshot,
                    to: waterfallContentLayer,
                    frame: absoluteFrame,
                    duration: duration,
                    timing: timing
                ) {
                    fadeOutLayerCount += 1
                }
            }
        }
        lastProjectionTransitionMovedLayerCount = movedLayerCount
        lastProjectionTransitionFadeInLayerCount = fadeInLayerCount
        lastProjectionTransitionFadeOutLayerCount = fadeOutLayerCount
        lastProjectionTransitionDurationMilliseconds = duration * 1_000
    }
    private func resetProjectionTransitionReport() {
        lastProjectionTransitionMovedLayerCount = 0
        lastProjectionTransitionFadeInLayerCount = 0
        lastProjectionTransitionFadeOutLayerCount = 0
        lastProjectionTransitionDurationMilliseconds = 0
    }
    @discardableResult
    private func addPositionAnimation(
        to layer: CALayer,
        from oldFrame: CGRect,
        duration: CFTimeInterval,
        timing: CAMediaTimingFunction
    ) -> Bool {
        let oldPosition = CGPoint(x: oldFrame.midX, y: oldFrame.midY)
        let newPosition = layer.position
        guard abs(oldPosition.x - newPosition.x) > 0.5 || abs(oldPosition.y - newPosition.y) > 0.5 else {
            return false
        }
        let animation = CABasicAnimation(keyPath: "position")
        animation.fromValue = oldPosition
        animation.toValue = newPosition
        animation.duration = duration
        animation.timingFunction = timing
        animation.isRemovedOnCompletion = true
        layer.add(animation, forKey: "quickSwitchProjectionPosition")
        return true
    }
    @discardableResult
    private func addFadeInAnimation(
        to layer: CALayer,
        duration: CFTimeInterval,
        timing: CAMediaTimingFunction
    ) -> Bool {
        let animation = CABasicAnimation(keyPath: "opacity")
        animation.fromValue = 0
        animation.toValue = layer.opacity
        animation.duration = duration
        animation.timingFunction = timing
        animation.isRemovedOnCompletion = true
        layer.add(animation, forKey: "quickSwitchProjectionFadeIn")
        return true
    }
    @discardableResult
    private func addFadeOutSnapshot(
        _ snapshot: ProjectionLayerSnapshot,
        to parentLayer: CALayer,
        frame: CGRect,
        duration: CFTimeInterval,
        timing: CAMediaTimingFunction
    ) -> Bool {
        let layer = snapshot.layer
        layer.removeAllAnimations()
        layer.removeFromSuperlayer()
        CATransaction.begin()
        CATransaction.setDisableActions(true)
        layer.frame = frame
        layer.opacity = max(layer.opacity, 0.01)
        layer.zPosition = max(layer.zPosition, 240)
        parentLayer.addSublayer(layer)
        CATransaction.commit()
        let animation = CABasicAnimation(keyPath: "opacity")
        animation.fromValue = layer.opacity
        animation.toValue = 0
        animation.duration = duration
        animation.timingFunction = timing
        animation.isRemovedOnCompletion = true
        CATransaction.begin()
        CATransaction.setDisableActions(true)
        layer.opacity = 0
        CATransaction.commit()
        layer.add(animation, forKey: "quickSwitchProjectionFadeOut")
        DispatchQueue.main.asyncAfter(deadline: .now() + duration + 0.05) { [weak layer] in
            layer?.removeFromSuperlayer()
        }
        return true
    }
    func reportDictionary() -> [String: Any] {
@@ -553,17 +1063,31 @@
            "glassBorderWidth": Double(glassLayer.borderWidth),
            "glassShadowOpacity": Double(glassLayer.shadowOpacity),
            "spaceLaneFrame": dictionary(from: laneLayer.frame),
            "spaceLaneBackgroundColor": colorDictionary(from: laneLayer.backgroundColor),
            "spaceLaneCornerRadius": Double(laneLayer.cornerRadius),
            "spaceLaneContentWidth": Double(spaceLaneContentWidth),
            "spaceLaneVisibleWidth": Double(laneLayer.bounds.width),
            "spaceLaneMaxScrollOffset": Double(spaceLaneMaxScrollOffset),
            "spaceLaneScrollable": spaceLaneMaxScrollOffset > 0,
            "spaceLaneDisplayGroupCount": spaceLaneDisplayGroups.count,
            "spaceLaneDisplayGroups": spaceLaneDisplayGroupReports(),
            "spaceLaneSegmentCount": spaceLaneSegments.count,
            "spaceLaneLabels": currentViewModel?.displays.flatMap { $0.spaces.map(\.label) } ?? [],
            "spaceLaneSegments": spaceLaneSegmentReports(),
            "hoverTargetKind": hoverTarget.kindDescription,
            "hoverTargetSource": hoverTargetSource.rawValue,
            "spaceLaneHoveredSpaceID": hoveredSpaceLaneID ?? NSNull(),
            "spaceLaneFocusedSpaceID": focusedSpaceID ?? NSNull(),
            "activeSpaceFocusID": activeSpaceFocusID ?? NSNull(),
            "spaceFilterLockedSpaceID": currentViewModel?.lockedSpaceID ?? NSNull(),
            "spaceFilterActive": currentViewModel?.lockedSpaceID != nil,
            "settingsButtonVisible": !settingsButtonLayer.isHidden,
            "settingsButtonHovered": isSettingsButtonHovered,
            "settingsButtonFrame": dictionary(from: settingsButtonLayer.frame),
            "spaceFocusAppGroupIndexes": spaceFocusedAppGroupIndexes(),
            "appHoverAssociatedSpaceIDs": appHoverAssociatedSpaceIDs.sorted(),
            "appHoverAssociatedSpaceLabels": appHoverAssociatedSpaceLabels,
            "windowHoverAssociatedSpaceID": windowHoverAssociatedSpaceID ?? NSNull(),
            "lastSpaceFocusedAppGroupIndex": lastSpaceFocusedAppGroupIndex ?? NSNull(),
            "lastSpaceLaneClickSpaceID": lastSpaceLaneClickSpaceID ?? NSNull(),
            "lastAppShelfScrollSyncedAppGroupIndex": lastAppShelfScrollSyncedAppGroupIndex ?? NSNull(),
@@ -591,13 +1115,19 @@
            "appShelfMinIconSize": Double(AppShelfMetrics.minIconSize),
            "appShelfItems": appShelfItemReports(),
            "waterfallFrame": dictionary(from: waterfallLayer.frame),
            "waterfallViewMode": waterfallViewMode.rawValue,
            "waterfallContentWidth": Double(waterfallContentWidth),
            "waterfallVisibleWidth": Double(waterfallLayer.bounds.width),
            "waterfallScrollOffset": Double(waterfallScrollOffset),
            "waterfallMaxScrollOffset": Double(waterfallMaxScrollOffset),
            "horizontalMasonryContentHeight": Double(horizontalMasonryContentHeight),
            "horizontalMasonryScrollOffset": Double(horizontalMasonryScrollOffset),
            "horizontalMasonryMaxScrollOffset": Double(horizontalMasonryMaxScrollOffset),
            "horizontalMasonryScrollable": horizontalMasonryMaxScrollOffset > 0,
            "waterfallAlignmentMinScrollOffset": Double(waterfallAlignmentScrollRange.lowerBound),
            "waterfallAlignmentMaxScrollOffset": Double(waterfallAlignmentScrollRange.upperBound),
            "waterfallScrollable": waterfallAlignmentScrollable,
            "waterfallScrollable": waterfallMaxScrollOffset > 0,
            "waterfallAlignmentScrollable": waterfallAlignmentScrollable,
            "waterfallColumnCount": waterfallColumns.count,
            "waterfallColumnNames": waterfallColumns.map(\.column.app.name),
            "waterfallClipsToBounds": waterfallLayer.masksToBounds,
@@ -606,6 +1136,10 @@
            "waterfallAlignmentTolerance": Double(WaterfallAlignmentMetrics.tolerance),
            "waterfallAlignmentAnimationDurationMilliseconds": Double(WaterfallAlignmentMetrics.animationDuration * 1_000),
            "waterfallAlignmentAnimationTimingName": "easeOut",
            "projectionTransitionMovedLayerCount": lastProjectionTransitionMovedLayerCount,
            "projectionTransitionFadeInLayerCount": lastProjectionTransitionFadeInLayerCount,
            "projectionTransitionFadeOutLayerCount": lastProjectionTransitionFadeOutLayerCount,
            "projectionTransitionDurationMilliseconds": lastProjectionTransitionDurationMilliseconds,
            "reduceMotionEffective": NSWorkspace.shared.accessibilityDisplayShouldReduceMotion,
            "selectedAppGroupIndex": effectiveSelection?.appGroupIndex ?? NSNull(),
            "selectedWindowIndex": effectiveSelection?.windowIndex ?? NSNull(),
@@ -627,6 +1161,13 @@
            "closeConfirmationVisible": !closeConfirmationLayers.containerLayer.isHidden,
            "closeConfirmationFrame": dictionary(from: closeConfirmationLayers.containerLayer.frame),
            "closeConfirmationArrowEdge": closeConfirmationArrowEdge?.rawValue ?? NSNull(),
            "closeFeedbackVisible": closeFeedback != nil && !closeFeedbackLayer.isHidden,
            "closeFeedbackKind": closeFeedback?.kind.rawValue ?? NSNull(),
            "closeFeedbackMessage": closeFeedback?.message ?? NSNull(),
            "closeFeedbackTargetKind": closeFeedback?.targetKind ?? NSNull(),
            "closeFeedbackAppGroupIndex": closeFeedback?.appGroupIndex ?? NSNull(),
            "closeFeedbackWindowID": closeFeedback?.windowID ?? NSNull(),
            "closeFeedbackFrame": dictionary(from: closeFeedbackLayer.frame),
            "mouseCommandsApplied": mouseCommandsApplied,
            "lastMouseCommand": lastMouseCommand ?? NSNull(),
            "lastClickedAppGroupIndex": lastClickedAppGroupIndex ?? NSNull(),
@@ -694,8 +1235,13 @@
            recordKeyboardCommand("enter")
            commitCurrentSelection()
        case "tab":
            tabIgnoredCount += 1
            recordKeyboardCommand("tabIgnored")
            if isHorizontalMasonryMode {
                recordKeyboardCommand("tab")
                moveSelection(.right)
            } else {
                tabIgnoredCount += 1
                recordKeyboardCommand("tabIgnored")
            }
        default:
            recordKeyboardCommand("unknown:\(command)")
        }
@@ -756,7 +1302,7 @@
            }
            recordMouseCommand("hover-space:\(spaceID)")
            if let segment = spaceLaneSegment(spaceID: spaceID) {
                hoverSpaceLaneSegment(segment)
                hoverSpaceLaneSegment(segment, source: .debug)
            }
        case "click-space" where parts.count == 2:
            guard let spaceID = UInt64(parts[1]) else {
@@ -765,8 +1311,24 @@
            }
            recordMouseCommand("click-space:\(spaceID)")
            if let segment = spaceLaneSegment(spaceID: spaceID) {
                clickSpaceLaneSegment(segment)
                clickSpaceLaneSegment(segment, clickCount: 1)
            }
        case "double-click-space" where parts.count == 2:
            guard let spaceID = UInt64(parts[1]) else {
                recordMouseCommand("invalid:\(command)")
                return
            }
            recordMouseCommand("double-click-space:\(spaceID)")
            if let segment = spaceLaneSegment(spaceID: spaceID) {
                clickSpaceLaneSegment(segment, clickCount: 1)
                clickSpaceLaneSegment(segment, clickCount: 2)
            }
        case "click-background":
            recordMouseCommand("click-background")
            _ = onBackgroundClick?()
        case "click-settings":
            recordMouseCommand("click-settings")
            clickSettingsButton(source: "debug")
        case "hover-card" where parts.count == 3:
            guard let appGroupIndex = Int(parts[1]), let windowIndex = Int(parts[2]) else {
                recordMouseCommand("invalid:\(command)")
@@ -774,7 +1336,7 @@
            }
            recordMouseCommand("hover-card:\(appGroupIndex):\(windowIndex)")
            if let card = waterfallCard(appGroupIndex: appGroupIndex, windowIndex: windowIndex) {
                hoverWindowCard(card)
                hoverWindowCard(card, source: .debug)
            }
        case "click-card" where parts.count == 3:
            guard let appGroupIndex = Int(parts[1]), let windowIndex = Int(parts[2]) else {
@@ -826,13 +1388,12 @@
    }
    private func hoverAppGroup(_ appGroupIndex: Int) {
        hoveredSpaceLaneID = nil
        hoveredCloseTarget = nil
        updateHoverState(
            appGroupIndex: appGroupIndex,
            windowID: nil,
            spaceID: nil,
            alignsWaterfallWithAppShelf: true
            alignsWaterfallWithAppShelf: true,
            source: .debug
        )
    }
@@ -847,19 +1408,18 @@
        beginCloseConfirmation(for: .app(appGroupIndex: appGroupIndex))
    }
    private func hoverWindowCard(_ card: WaterfallCardLayers) {
        hoveredSpaceLaneID = nil
        hoveredCloseTarget = nil
    private func hoverWindowCard(_ card: WaterfallCardLayers, source: HoverTargetSource = .event) {
        updateHoverState(
            appGroupIndex: card.item.appGroupIndex,
            windowID: card.item.window.id,
            spaceID: card.item.primarySpaceID
            spaceID: card.item.primarySpaceID,
            source: source
        )
    }
    private func hoverCardCloseButton(appGroupIndex: Int, windowIndex: Int) {
        guard let card = waterfallCard(appGroupIndex: appGroupIndex, windowIndex: windowIndex) else { return }
        hoverWindowCard(card)
        hoverWindowCard(card, source: .debug)
        hoveredCloseTarget = .window(
            appGroupIndex: appGroupIndex,
            windowIndex: windowIndex,
@@ -880,33 +1440,23 @@
        )
    }
    private func hoverSpaceLaneSegment(_ segment: SpaceLaneSegmentLayers) {
        focusSpace(segment.space.id, persistent: false)
    private func hoverSpaceLaneSegment(_ segment: SpaceLaneSegmentLayers, source: HoverTargetSource = .event) {
        focusSpace(segment.space.id, persistent: false, source: source)
    }
    private func clickSpaceLaneSegment(_ segment: SpaceLaneSegmentLayers) {
    private func clickSpaceLaneSegment(_ segment: SpaceLaneSegmentLayers, clickCount: Int = 1) {
        DevelopmentDiagnostics.log("quickSwitch.view.clickSpaceLane", [
            "spaceID": segment.space.id,
            "label": segment.space.label
            "label": segment.space.label,
            "clickCount": clickCount
        ])
        lastSpaceLaneClickSpaceID = segment.space.id
        guard let firstCard = firstWaterfallCard(inSpaceID: segment.space.id) else {
            DevelopmentDiagnostics.log("quickSwitch.view.clickSpaceLane.emptySpaceUnsupported", [
                "spaceID": segment.space.id,
                "label": segment.space.label
            ])
            return
        }
        commitWindowCard(firstCard, trigger: "spaceLane")
        onSpaceLaneClick?(segment.space.id, clickCount)
        lastSpaceLaneClickSpaceID = segment.space.id
    }
    private func focusSpace(_ spaceID: UInt64, persistent: Bool) {
        hoveredAppGroupIndex = nil
        hoveredWindowID = nil
        hoveredSpaceID = spaceID
        hoveredSpaceLaneID = spaceID
    private func focusSpace(_ spaceID: UInt64, persistent: Bool, source: HoverTargetSource = .event) {
        setHoverTarget(.space(spaceID), source: source)
        if persistent {
            focusedSpaceID = spaceID
            lastSpaceLaneClickSpaceID = spaceID
@@ -1035,28 +1585,76 @@
        appGroupIndex: Int?,
        windowID: UInt32?,
        spaceID: UInt64?,
        alignsWaterfallWithAppShelf: Bool = false
        alignsWaterfallWithAppShelf: Bool = false,
        source: HoverTargetSource = .event
    ) {
        guard hoveredAppGroupIndex != appGroupIndex
            || hoveredWindowID != windowID
            || hoveredSpaceID != spaceID
        else {
            if alignsWaterfallWithAppShelf, let appGroupIndex {
                alignWaterfallColumnWithAppShelfIcon(appGroupIndex: appGroupIndex, animated: true)
            }
            return
        let target: HoverTarget
        if let appGroupIndex, let windowID {
            target = .window(appGroupIndex: appGroupIndex, windowID: windowID, spaceID: spaceID)
        } else if let appGroupIndex {
            target = .app(appGroupIndex)
        } else {
            target = .none
        }
        hoveredAppGroupIndex = appGroupIndex
        hoveredWindowID = windowID
        hoveredSpaceID = spaceID
        if alignsWaterfallWithAppShelf, let appGroupIndex {
        setHoverTarget(target, source: source, alignsWaterfallWithAppShelf: alignsWaterfallWithAppShelf)
    }
    private func refreshHoverTarget(at windowLocation: CGPoint) {
        guard debugHoveredAppGroupIndex == nil else { return }
        let target = resolveHoverTarget(at: windowLocation)
        setHoverTarget(target, alignsWaterfallWithAppShelf: target.shouldAlignWaterfallWithAppShelf)
    }
    private func resolveHoverTarget(at windowLocation: CGPoint) -> HoverTarget {
        if let segment = spaceLaneSegment(at: windowLocation) {
            return .space(segment.space.id)
        }
        if let card = waterfallCard(at: windowLocation) {
            return .window(
                appGroupIndex: card.item.appGroupIndex,
                windowID: card.item.window.id,
                spaceID: card.item.primarySpaceID
            )
        }
        if let item = appShelfItem(at: windowLocation) {
            return .app(item.item.appGroupIndex)
        }
        return .none
    }
    private func setHoverTarget(
        _ target: HoverTarget,
        source: HoverTargetSource = .event,
        alignsWaterfallWithAppShelf: Bool = false
    ) {
        let previousTarget = hoverTarget
        let previousSource = hoverTargetSource
        hoverTarget = target
        hoverTargetSource = source
        hoveredAppGroupIndex = target.appGroupIndex
        hoveredWindowID = target.windowID
        hoveredSpaceID = target.spaceID
        hoveredSpaceLaneID = target.spaceLaneID
        if alignsWaterfallWithAppShelf, let appGroupIndex = target.appGroupIndex {
            alignWaterfallColumnWithAppShelfIcon(appGroupIndex: appGroupIndex, animated: true)
        }
        guard previousTarget != target || previousSource != source else { return }
        needsLayout = true
    }
    private func moveSelection(_ direction: QuickSwitchKeyboardDirection) {
        if isHorizontalMasonryMode {
            moveHorizontalMasonrySelection(direction)
            return
        }
        guard let currentViewModel,
              let snapshot = snapshotForFocus(from: currentViewModel),
              let current = currentSelection ?? currentViewModel.initialSelection,
@@ -1086,6 +1684,113 @@
            "windowID": next.windowID
        ])
        needsLayout = true
    }
    private func moveHorizontalMasonrySelection(_ direction: QuickSwitchKeyboardDirection) {
        guard let current = currentSelection ?? currentViewModel?.initialSelection,
              let next = nextHorizontalMasonrySelection(from: current, direction: direction)
        else {
            DevelopmentDiagnostics.log("quickSwitch.view.moveHorizontalMasonrySelection.blocked", [
                "direction": String(describing: direction),
                "hasSelection": (currentSelection ?? currentViewModel?.initialSelection) != nil
            ])
            return
        }
        columnSelectionHistory[current.appGroupIndex] = current.windowIndex
        currentSelection = next
        columnSelectionHistory[next.appGroupIndex] = next.windowIndex
        ensureCurrentSelectionVisible(horizontalIntent: .alignWithAppShelf(animated: true))
        DevelopmentDiagnostics.log("quickSwitch.view.moveHorizontalMasonrySelection", [
            "direction": String(describing: direction),
            "appGroupIndex": next.appGroupIndex,
            "windowIndex": next.windowIndex,
            "windowID": next.windowID
        ])
        needsLayout = true
    }
    private func nextHorizontalMasonrySelection(
        from current: QuickSwitchSelection,
        direction: QuickSwitchKeyboardDirection
    ) -> QuickSwitchSelection? {
        layoutSubtreeIfNeeded()
        let cards = horizontalMasonryCardsInPlacementOrder()
        guard let currentIndex = cards.firstIndex(where: { $0.item.window.id == current.windowID }) else {
            return cards.first.map(selectionForCard)
        }
        switch direction {
        case .right:
            return selectionForCard(cards[(currentIndex + 1) % cards.count])
        case .left:
            return selectionForCard(cards[(currentIndex - 1 + cards.count) % cards.count])
        case .up:
            return nearestHorizontalMasonrySelection(from: cards[currentIndex], direction: .up)
                ?? selectionForCard(cards.first ?? cards[currentIndex])
        case .down:
            return nearestHorizontalMasonrySelection(from: cards[currentIndex], direction: .down)
                ?? selectionForCard(cards.last ?? cards[currentIndex])
        }
    }
    private func nearestHorizontalMasonrySelection(
        from currentCard: WaterfallCardLayers,
        direction: QuickSwitchKeyboardDirection
    ) -> QuickSwitchSelection? {
        let currentFrame = currentCard.containerLayer.frame
        let candidates = horizontalMasonryCardsInPlacementOrder().filter { card in
            guard card.item.window.id != currentCard.item.window.id else { return false }
            switch direction {
            case .up:
                return card.containerLayer.frame.minY >= currentFrame.maxY - 0.5
            case .down:
                return card.containerLayer.frame.maxY <= currentFrame.minY + 0.5
            case .left, .right:
                return false
            }
        }
        let best = candidates.min { lhs, rhs in
            let lhsFrame = lhs.containerLayer.frame
            let rhsFrame = rhs.containerLayer.frame
            let lhsPrimaryDistance = direction == .up
                ? lhsFrame.minY - currentFrame.maxY
                : currentFrame.minY - lhsFrame.maxY
            let rhsPrimaryDistance = direction == .up
                ? rhsFrame.minY - currentFrame.maxY
                : currentFrame.minY - rhsFrame.maxY
            if abs(lhsPrimaryDistance - rhsPrimaryDistance) > 0.5 {
                return lhsPrimaryDistance < rhsPrimaryDistance
            }
            let lhsHorizontalDistance = abs(lhsFrame.midX - currentFrame.midX)
            let rhsHorizontalDistance = abs(rhsFrame.midX - currentFrame.midX)
            if abs(lhsHorizontalDistance - rhsHorizontalDistance) > 0.5 {
                return lhsHorizontalDistance < rhsHorizontalDistance
            }
            return lhs.item.globalIndex < rhs.item.globalIndex
        }
        return best.map(selectionForCard)
    }
    private func horizontalMasonryCardsInPlacementOrder() -> [WaterfallCardLayers] {
        waterfallColumns
            .sorted { $0.column.appGroupIndex < $1.column.appGroupIndex }
            .flatMap { column in
                column.cards.sorted { $0.item.windowIndex < $1.item.windowIndex }
            }
    }
    private func selectionForCard(_ card: WaterfallCardLayers) -> QuickSwitchSelection {
        QuickSwitchSelection(
            appGroupIndex: card.item.appGroupIndex,
            windowIndex: card.item.windowIndex,
            windowID: card.item.window.id
        )
    }
    private func commitCurrentSelection() {
@@ -1145,9 +1850,24 @@
        _ selection: QuickSwitchSelection,
        horizontalIntent: WaterfallHorizontalIntent = .reveal
    ) {
        if isHorizontalMasonryMode {
            switch horizontalIntent {
            case .reveal:
                ensureHorizontalMasonrySelectionVisible(selection, animated: false)
            case .alignWithAppShelf(let animated):
                ensureHorizontalMasonrySelectionVisible(selection, animated: animated)
            }
            return
        }
        guard
            let column = waterfallColumns.first(where: { $0.column.appGroupIndex == selection.appGroupIndex })
        else {
            return
        }
        if waterfallShouldKeepFilteredColumnsCentered {
            ensureWaterfallCardVisibleVertically(selection)
            return
        }
@@ -1161,11 +1881,16 @@
    }
    private func ensureWaterfallCardVisibleVertically(_ selection: QuickSwitchSelection) {
        guard !isHorizontalMasonryMode else {
            ensureHorizontalMasonrySelectionVisible(selection, animated: false)
            return
        }
        let visibleHeight = max(
            1,
            waterfallLayer.bounds.height
                - WaterfallMetrics.headerHeight
                - WaterfallMetrics.columnPadding * 2
                - WaterfallMetrics.columnVerticalPadding * 2
        )
        let cardStride = WaterfallMetrics.cardHeight + WaterfallMetrics.cardGap
        let cardStart = CGFloat(selection.windowIndex) * cardStride
@@ -1188,6 +1913,11 @@
    }
    private func alignWaterfallColumnWithAppShelfIcon(appGroupIndex: Int, animated: Bool) {
        if isHorizontalMasonryMode {
            ensureHorizontalMasonryAppVisible(appGroupIndex, animated: animated)
            return
        }
        guard
            let item = appShelfItems.first(where: { $0.item.appGroupIndex == appGroupIndex }),
            let column = waterfallColumns.first(where: { $0.column.appGroupIndex == appGroupIndex })
@@ -1214,6 +1944,11 @@
    }
    private func ensureWaterfallColumnVisible(_ appGroupIndex: Int) {
        if isHorizontalMasonryMode {
            ensureHorizontalMasonryAppVisible(appGroupIndex, animated: false)
            return
        }
        guard let column = waterfallColumns.first(where: { $0.column.appGroupIndex == appGroupIndex }) else {
            return
        }
@@ -1222,18 +1957,31 @@
    }
    private func ensureWaterfallColumnVisible(_ column: WaterfallColumnLayers) {
        if isHorizontalMasonryMode {
            ensureHorizontalMasonryAppVisible(column.column.appGroupIndex, animated: false)
            return
        }
        waterfallScrollOffset = clampedWaterfallOffset(
            scrollOffset(
                makingVisible: column.containerLayer.frame,
                currentOffset: waterfallScrollOffset,
                visibleWidth: waterfallLayer.bounds.width,
                maxOffset: waterfallMaxScrollOffset,
                inset: WaterfallMetrics.revealPadding
                inset: WaterfallMetrics.horizontalRevealPadding
            )
        )
    }
    private var waterfallAlignmentScrollRange: ClosedRange<CGFloat> {
        if isHorizontalMasonryMode {
            return 0...0
        }
        if waterfallShouldKeepFilteredColumnsCentered {
            return 0...0
        }
        var minimumOffset: CGFloat = 0
        var maximumOffset = waterfallMaxScrollOffset
@@ -1258,6 +2006,10 @@
    private func clampedWaterfallAlignmentOffset(_ offset: CGFloat) -> CGFloat {
        let range = waterfallAlignmentScrollRange
        return min(max(range.lowerBound, offset), range.upperBound)
    }
    private var waterfallShouldKeepFilteredColumnsCentered: Bool {
        currentViewModel?.lockedSpaceID != nil && waterfallMaxScrollOffset <= 0.5
    }
    private func setWaterfallScrollOffset(_ offset: CGFloat, animated: Bool) {
@@ -1292,6 +2044,80 @@
        animation.timingFunction = CAMediaTimingFunction(name: WaterfallAlignmentMetrics.animationTimingName)
        animation.isRemovedOnCompletion = true
        waterfallContentLayer.add(animation, forKey: "waterfallColumnAlignment")
    }
    private func ensureHorizontalMasonrySelectionVisible(
        _ selection: QuickSwitchSelection,
        animated: Bool
    ) {
        guard let card = waterfallCard(
            appGroupIndex: selection.appGroupIndex,
            windowIndex: selection.windowIndex
        ) else {
            return
        }
        let visibleFrame = card.containerLayer.frame.offsetBy(
            dx: 0,
            dy: waterfallContentLayer.frame.minY
        )
        let visibleHeight = waterfallLayer.bounds.height
        let padding = WaterfallMetrics.revealPadding
        var nextOffset = horizontalMasonryScrollOffset
        if visibleFrame.maxY > visibleHeight - padding {
            nextOffset -= visibleFrame.maxY - (visibleHeight - padding)
        } else if visibleFrame.minY < padding {
            nextOffset += padding - visibleFrame.minY
        }
        setHorizontalMasonryScrollOffset(nextOffset, animated: animated)
    }
    private func ensureHorizontalMasonryAppVisible(_ appGroupIndex: Int, animated: Bool) {
        guard let firstCard = waterfallColumns
            .first(where: { $0.column.appGroupIndex == appGroupIndex })?
            .cards
            .sorted(by: { $0.item.windowIndex < $1.item.windowIndex })
            .first
        else {
            return
        }
        let cardTopDistance = horizontalMasonryContentHeight - firstCard.containerLayer.frame.maxY
        setHorizontalMasonryScrollOffset(
            cardTopDistance - WaterfallMetrics.revealPadding,
            animated: animated
        )
    }
    private func setHorizontalMasonryScrollOffset(_ offset: CGFloat, animated: Bool) {
        let nextOffset = clampedHorizontalMasonryOffset(offset)
        let previousPositionY = waterfallContentLayer.presentation()?.position.y
            ?? waterfallContentLayer.position.y
        horizontalMasonryScrollOffset = nextOffset
        CATransaction.begin()
        CATransaction.setDisableActions(true)
        waterfallContentLayer.frame = horizontalMasonryContentFrame()
        CATransaction.commit()
        let nextPositionY = waterfallContentLayer.position.y
        guard animated,
              !NSWorkspace.shared.accessibilityDisplayShouldReduceMotion,
              abs(previousPositionY - nextPositionY) > 0.5
        else {
            waterfallContentLayer.removeAnimation(forKey: "horizontalMasonryAlignment")
            return
        }
        let animation = CABasicAnimation(keyPath: "position.y")
        animation.fromValue = previousPositionY
        animation.toValue = nextPositionY
        animation.duration = WaterfallAlignmentMetrics.animationDuration
        animation.timingFunction = CAMediaTimingFunction(name: WaterfallAlignmentMetrics.animationTimingName)
        animation.isRemovedOnCompletion = true
        waterfallContentLayer.add(animation, forKey: "horizontalMasonryAlignment")
    }
    private func scrollOffset(
@@ -1408,8 +2234,8 @@
        glassLayer.shadowOpacity = 0
        rootLayer.addSublayer(glassLayer)
        laneLayer.backgroundColor = NSColor.controlBackgroundColor.withAlphaComponent(0.68).cgColor
        laneLayer.cornerRadius = 16
        laneLayer.backgroundColor = NSColor.clear.cgColor
        laneLayer.cornerRadius = 0
        laneLayer.masksToBounds = true
        glassLayer.addSublayer(laneLayer)
        laneLayer.addSublayer(spaceLaneContentLayer)
@@ -1427,6 +2253,44 @@
        closeConfirmationLayers.containerLayer.isHidden = true
        glassLayer.addSublayer(closeConfirmationLayers.containerLayer)
        closeFeedbackLayer.isHidden = true
        closeFeedbackLayer.opacity = 0
        closeFeedbackLayer.cornerRadius = 11
        closeFeedbackLayer.borderWidth = 1
        closeFeedbackLayer.masksToBounds = false
        closeFeedbackLayer.shadowColor = NSColor.black.cgColor
        closeFeedbackLayer.shadowOpacity = 0.14
        closeFeedbackLayer.shadowRadius = 16
        closeFeedbackLayer.shadowOffset = CGSize(width: 0, height: -5)
        closeFeedbackLayer.zPosition = 190
        closeFeedbackTextLayer.contentsScale = backingScaleFactor
        closeFeedbackTextLayer.font = NSFont.systemFont(ofSize: 13, weight: .medium)
        closeFeedbackTextLayer.fontSize = 13
        closeFeedbackTextLayer.alignmentMode = .center
        closeFeedbackTextLayer.truncationMode = .end
        closeFeedbackLayer.addSublayer(closeFeedbackTextLayer)
        glassLayer.addSublayer(closeFeedbackLayer)
        settingsButtonLayer.cornerRadius = 10
        settingsButtonLayer.masksToBounds = false
        settingsButtonLayer.borderWidth = 1
        settingsButtonLayer.shadowColor = NSColor.black.cgColor
        settingsButtonLayer.shadowOffset = CGSize(width: 0, height: -2)
        settingsButtonLayer.zPosition = 170
        settingsButtonIconLayer.contentsGravity = .resizeAspect
        settingsButtonIconLayer.contentsScale = backingScaleFactor
        settingsButtonIconLayer.contents = settingsIconImage()
        settingsButtonFallbackTextLayer.contentsScale = backingScaleFactor
        settingsButtonFallbackTextLayer.string = "âš™"
        settingsButtonFallbackTextLayer.font = NSFont.systemFont(ofSize: 18, weight: .regular)
        settingsButtonFallbackTextLayer.fontSize = 18
        settingsButtonFallbackTextLayer.alignmentMode = .center
        settingsButtonFallbackTextLayer.foregroundColor = NSColor.secondaryLabelColor.cgColor
        settingsButtonFallbackTextLayer.isHidden = settingsButtonIconLayer.contents != nil
        settingsButtonLayer.addSublayer(settingsButtonIconLayer)
        settingsButtonLayer.addSublayer(settingsButtonFallbackTextLayer)
        glassLayer.addSublayer(settingsButtonLayer)
    }
    private func rebuildAppShelfItems() {
@@ -1434,22 +2298,15 @@
            item.containerLayer.removeFromSuperlayer()
        }
        let selectedAppGroupIndex = effectiveSelection?.appGroupIndex
        appShelfItems = (currentViewModel?.appShelf ?? []).map { item in
            let container = CALayer()
            container.name = item.app.name
            let background = CALayer()
            background.cornerRadius = 10
            background.backgroundColor = (item.appGroupIndex == selectedAppGroupIndex
                ? NSColor.systemFill.withAlphaComponent(0.16)
                : NSColor.clear
            ).cgColor
            background.borderColor = (item.appGroupIndex == selectedAppGroupIndex
                ? NSColor.separatorColor.withAlphaComponent(0.36)
                : NSColor.clear
            ).cgColor
            background.borderWidth = item.appGroupIndex == selectedAppGroupIndex ? 1 : 0
            background.backgroundColor = NSColor.clear.cgColor
            background.borderColor = NSColor.clear.cgColor
            background.borderWidth = 0
            let icon = CALayer()
            icon.contentsGravity = .resizeAspect
@@ -1523,7 +2380,8 @@
                string: column.app.name,
                fontSize: 13,
                weight: .semibold,
                color: .labelColor
                color: .labelColor,
                alignment: .center
            )
            let count = makeTextLayer(
                string: "\(column.windows.count)",
@@ -1632,66 +2490,108 @@
    }
    private func rebuildSpaceLaneSegments() {
        for segment in spaceLaneSegments {
            segment.containerLayer.removeFromSuperlayer()
        for group in spaceLaneDisplayGroups {
            group.containerLayer.removeFromSuperlayer()
        }
        let spaces = currentViewModel?.displays.flatMap(\.spaces) ?? []
        spaceLaneSegments = spaces.map { space in
            let container = CALayer()
            container.name = space.label
            container.cornerRadius = 10
            container.borderWidth = 1
            container.borderColor = NSColor.separatorColor.withAlphaComponent(0.34).cgColor
            container.backgroundColor = spaceColor(for: space).cgColor
            container.shadowColor = NSColor.black.cgColor
        var groups: [SpaceLaneDisplayGroupLayers] = []
        var allSegments: [SpaceLaneSegmentLayers] = []
            let labelLayer = makeTextLayer(
                string: space.label,
                fontSize: 15,
                weight: .semibold,
                color: .labelColor
            )
            let countLayer = makeTextLayer(
                string: "\(space.windowCount)",
                fontSize: 12,
                weight: .medium,
                color: .secondaryLabelColor,
                alignment: .center
            )
            let appLayer = makeTextLayer(
                string: appIdentifierText(for: space),
                fontSize: 12,
                weight: space.type == .fullscreen ? .medium : .regular,
                color: space.type == .fullscreen ? .labelColor : .secondaryLabelColor,
                alignment: space.type == .fullscreen ? .center : .left
            )
            let windowBlocks = space.type == .fullscreen
                ? []
                : makeWindowBlocks(count: min(space.windowCount, 5), space: space)
            let fullscreenMarkerLayer = makeFullscreenMarkerLayer(for: space)
        for display in currentViewModel?.displays ?? [] {
            let groupContainer = CALayer()
            groupContainer.name = display.displayLabel
            groupContainer.cornerRadius = 14
            groupContainer.masksToBounds = false
            groupContainer.borderWidth = 0
            groupContainer.borderColor = NSColor.clear.cgColor
            groupContainer.backgroundColor = NSColor.windowBackgroundColor.cgColor
            groupContainer.shadowColor = NSColor.black.cgColor
            groupContainer.shadowOpacity = 0
            groupContainer.shadowRadius = 0
            groupContainer.shadowOffset = .zero
            container.addSublayer(labelLayer)
            container.addSublayer(countLayer)
            container.addSublayer(appLayer)
            if let fullscreenMarkerLayer {
                container.addSublayer(fullscreenMarkerLayer)
            let segments = display.spaces.map { space in
                let container = CAGradientLayer()
                container.name = space.label
                container.cornerRadius = 10
                container.borderWidth = 1
                container.borderColor = NSColor.separatorColor.withAlphaComponent(0.34).cgColor
                container.backgroundColor = NSColor.clear.cgColor
                container.startPoint = CGPoint(x: 0.5, y: 1.0)
                container.endPoint = CGPoint(x: 0.5, y: 0.0)
                container.shadowColor = NSColor.black.cgColor
                let labelLayer = makeTextLayer(
                    string: space.label,
                    fontSize: 15,
                    weight: .semibold,
                    color: .labelColor
                )
                let countLayer = makeTextLayer(
                    string: "\(space.windowCount)",
                    fontSize: 12,
                    weight: .medium,
                    color: .secondaryLabelColor,
                    alignment: .center
                )
                let appLayer = makeTextLayer(
                    string: appIdentifierText(for: space),
                    fontSize: 12,
                    weight: space.type == .fullscreen ? .medium : .regular,
                    color: space.type == .fullscreen ? .labelColor : .secondaryLabelColor,
                    alignment: space.type == .fullscreen ? .center : .left
                )
                let splitAppLayers = splitViewAppNames(for: space).map { name in
                    makeTextLayer(
                        string: name,
                        fontSize: 12,
                        weight: .medium,
                        color: .labelColor,
                        alignment: .center
                    )
                }
                let windowBlocks = space.type == .fullscreen
                    ? []
                    : makeWindowBlocks(count: min(space.windowCount, 5), space: space)
                let fullscreenMarkerLayer = makeFullscreenMarkerLayer(for: space)
                container.addSublayer(labelLayer)
                container.addSublayer(countLayer)
                container.addSublayer(appLayer)
                if let fullscreenMarkerLayer {
                    container.addSublayer(fullscreenMarkerLayer)
                }
                for splitAppLayer in splitAppLayers {
                    container.addSublayer(splitAppLayer)
                }
                for block in windowBlocks {
                    container.addSublayer(block)
                }
                groupContainer.addSublayer(container)
                return SpaceLaneSegmentLayers(
                    space: space,
                    containerLayer: container,
                    labelLayer: labelLayer,
                    countLayer: countLayer,
                    appLayer: appLayer,
                    splitAppLayers: splitAppLayers,
                    windowBlocks: windowBlocks,
                    fullscreenMarkerLayer: fullscreenMarkerLayer
                )
            }
            for block in windowBlocks {
                container.addSublayer(block)
            }
            spaceLaneContentLayer.addSublayer(container)
            return SpaceLaneSegmentLayers(
                space: space,
                containerLayer: container,
                labelLayer: labelLayer,
                countLayer: countLayer,
                appLayer: appLayer,
                windowBlocks: windowBlocks,
                fullscreenMarkerLayer: fullscreenMarkerLayer
            )
            spaceLaneContentLayer.addSublayer(groupContainer)
            groups.append(SpaceLaneDisplayGroupLayers(
                display: display,
                containerLayer: groupContainer,
                segments: segments
            ))
            allSegments.append(contentsOf: segments)
        }
        spaceLaneDisplayGroups = groups
        spaceLaneSegments = allSegments
    }
    private func layoutLayers() {
@@ -1740,8 +2640,41 @@
        layoutAppShelfItems()
        layoutWaterfallColumns()
        layoutCloseConfirmation()
        layoutCloseFeedback()
        layoutSettingsButton()
        CATransaction.commit()
    }
    private func layoutSettingsButton() {
        let size: CGFloat = 34
        let topMargin = topSafeAreaInset + RootLayoutMetrics.topContentMargin
        let x = max(
            RootLayoutMetrics.horizontalMargin,
            glassLayer.bounds.width - RootLayoutMetrics.horizontalMargin - size
        )
        let y = max(
            RootLayoutMetrics.bottomMargin,
            glassLayer.bounds.height - topMargin - size
        )
        settingsButtonLayer.frame = CGRect(x: x, y: y, width: size, height: size)
        settingsButtonLayer.backgroundColor = NSColor.windowBackgroundColor
            .withAlphaComponent(isSettingsButtonHovered ? 0.78 : 0.54)
            .cgColor
        settingsButtonLayer.borderColor = NSColor.separatorColor
            .withAlphaComponent(isSettingsButtonHovered ? 0.42 : 0.26)
            .cgColor
        settingsButtonLayer.shadowOpacity = isSettingsButtonHovered ? 0.14 : 0.08
        settingsButtonLayer.shadowRadius = isSettingsButtonHovered ? 9 : 6
        settingsButtonIconLayer.contentsScale = backingScaleFactor
        settingsButtonFallbackTextLayer.contentsScale = backingScaleFactor
        let iconInset: CGFloat = 8
        settingsButtonIconLayer.frame = settingsButtonLayer.bounds.insetBy(dx: iconInset, dy: iconInset)
        settingsButtonFallbackTextLayer.frame = settingsButtonLayer.bounds.insetBy(dx: 0, dy: 6)
        settingsButtonFallbackTextLayer.foregroundColor = (isSettingsButtonHovered
            ? NSColor.labelColor
            : NSColor.secondaryLabelColor
        ).cgColor
    }
    private var topSafeAreaInset: CGFloat {
@@ -1823,15 +2756,34 @@
    }
    private func layoutSpaceLaneSegments() {
        guard !spaceLaneSegments.isEmpty else { return }
        guard !spaceLaneDisplayGroups.isEmpty, !spaceLaneSegments.isEmpty else { return }
        let gap: CGFloat = 10
        let segmentHeight = max(1, laneLayer.bounds.height - 20)
        let availableWidth = laneLayer.bounds.width - 24 - CGFloat(spaceLaneSegments.count - 1) * gap
        let segmentWidth = max(96, min(150, availableWidth / CGFloat(spaceLaneSegments.count)))
        let groupOuterVerticalInset: CGFloat = 6
        let groupHeight = max(1, laneLayer.bounds.height - groupOuterVerticalInset * 2)
        let segmentHeight = max(1, groupHeight - SpaceLaneMetrics.groupVerticalPadding * 2)
        let groupGapWidth = CGFloat(max(0, spaceLaneDisplayGroups.count - 1)) * SpaceLaneMetrics.groupGap
        let segmentGapWidth = spaceLaneDisplayGroups.reduce(CGFloat(0)) { total, group in
            total + CGFloat(max(0, group.segments.count - 1)) * SpaceLaneMetrics.segmentGap
        }
        let groupPaddingWidth = CGFloat(spaceLaneDisplayGroups.count) * SpaceLaneMetrics.groupHorizontalPadding * 2
        let availableWidth = laneLayer.bounds.width
            - SpaceLaneMetrics.horizontalPadding * 2
            - groupGapWidth
            - segmentGapWidth
            - groupPaddingWidth
        let segmentWidth = max(
            SpaceLaneMetrics.segmentMinWidth,
            min(SpaceLaneMetrics.segmentMaxWidth, availableWidth / CGFloat(spaceLaneSegments.count))
        )
        let groupWidths = spaceLaneDisplayGroups.map { group in
            SpaceLaneMetrics.groupHorizontalPadding * 2
                + CGFloat(group.segments.count) * segmentWidth
                + CGFloat(max(0, group.segments.count - 1)) * SpaceLaneMetrics.segmentGap
        }
        let segmentGroupWidth = groupWidths.reduce(0, +) + groupGapWidth
        spaceLaneContentWidth = max(
            laneLayer.bounds.width,
            24 + CGFloat(spaceLaneSegments.count) * segmentWidth + CGFloat(spaceLaneSegments.count - 1) * gap
            SpaceLaneMetrics.horizontalPadding * 2 + segmentGroupWidth
        )
        spaceLaneScrollOffset = clampedSpaceLaneOffset(spaceLaneScrollOffset)
        spaceLaneContentLayer.frame = CGRect(
@@ -1841,13 +2793,35 @@
            height: laneLayer.bounds.height
        )
        var x: CGFloat = 12
        var x = max(
            SpaceLaneMetrics.horizontalPadding,
            (spaceLaneContentWidth - segmentGroupWidth) / 2
        )
        for segment in spaceLaneSegments {
            segment.containerLayer.frame = CGRect(x: x, y: 10, width: segmentWidth, height: segmentHeight)
            applySpaceLaneVisualState(segment)
            layoutSpaceLaneSegmentContents(segment)
            x += segmentWidth + gap
        for (index, group) in spaceLaneDisplayGroups.enumerated() {
            let groupWidth = groupWidths[index]
            group.containerLayer.frame = CGRect(
                x: x,
                y: groupOuterVerticalInset,
                width: groupWidth,
                height: groupHeight
            )
            applySpaceLaneDisplayGroupVisualState(group)
            var segmentX = SpaceLaneMetrics.groupHorizontalPadding
            for segment in group.segments {
                segment.containerLayer.frame = CGRect(
                    x: segmentX,
                    y: SpaceLaneMetrics.groupVerticalPadding,
                    width: segmentWidth,
                    height: segmentHeight
                )
                applySpaceLaneVisualState(segment)
                layoutSpaceLaneSegmentContents(segment)
                segmentX += segmentWidth + SpaceLaneMetrics.segmentGap
            }
            x += groupWidth + SpaceLaneMetrics.groupGap
        }
    }
@@ -1859,36 +2833,127 @@
        min(max(0, offset), spaceLaneMaxScrollOffset)
    }
    private func applySpaceLaneVisualState(_ segment: SpaceLaneSegmentLayers) {
        let isHovered = segment.space.id == hoveredSpaceID
        let isFocused = segment.space.id == activeSpaceFocusID
        let isCurrent = segment.space.isCurrent
        let isActive = isHovered || isFocused
    private func applySpaceLaneDisplayGroupVisualState(_ group: SpaceLaneDisplayGroupLayers) {
        let hasActiveSegment = group.segments.contains { segment in
            segment.space.id == activeSpaceFocusID
                || appHoverAssociatedSpaceIDs.contains(segment.space.id)
                || segment.space.id == windowHoverAssociatedSpaceID
                || segment.space.id == currentViewModel?.lockedSpaceID
        }
        let hasCurrentSegment = group.display.spaces.contains { $0.isCurrent }
        group.containerLayer.backgroundColor = NSColor.windowBackgroundColor.cgColor
        group.containerLayer.borderColor = NSColor.clear.cgColor
        group.containerLayer.borderWidth = 0
        group.containerLayer.shadowOpacity = 0
        group.containerLayer.shadowRadius = 0
        group.containerLayer.shadowOffset = .zero
        group.containerLayer.zPosition = hasActiveSegment ? 8 : hasCurrentSegment ? 4 : 0
        group.containerLayer.shadowPath = nil
    }
        segment.containerLayer.borderWidth = (isCurrent || isActive) ? 1.5 : 1
        segment.containerLayer.borderColor = (isActive
            ? NSColor.controlAccentColor.withAlphaComponent(0.54)
            : isCurrent
                ? NSColor.labelColor.withAlphaComponent(0.34)
    private func applySpaceLaneVisualState(_ segment: SpaceLaneSegmentLayers) {
        let isHovered = segment.space.id == activeSpaceFocusID
        let isFocused = segment.space.id == activeSpaceFocusID
        let isLocked = segment.space.id == currentViewModel?.lockedSpaceID
        let isCurrent = segment.space.isCurrent
        let hasWindows = segment.space.windowCount > 0
        let isAppAssociated = appHoverAssociatedSpaceIDs.contains(segment.space.id)
        let isWindowAssociated = segment.space.id == windowHoverAssociatedSpaceID
        let isActive = isHovered || isFocused || isLocked
        let isAssociated = (isAppAssociated || isWindowAssociated) && !isActive
        segment.containerLayer.borderWidth = (hasWindows || isCurrent || isActive || isAssociated) ? 1.5 : 1
        segment.containerLayer.borderColor = (isLocked
            ? NSColor.white.withAlphaComponent(0.86)
            : isActive
            ? spaceLaneOccupiedColor.withAlphaComponent(isLocked ? 0.92 : 0.62)
            : isAssociated
                ? spaceLaneOccupiedColor.withAlphaComponent(0.50)
                : hasWindows
                    ? spaceLaneOccupiedColor.withAlphaComponent(isCurrent ? 0.54 : 0.44)
                : isCurrent
                    ? NSColor.labelColor.withAlphaComponent(0.34)
                : NSColor.separatorColor.withAlphaComponent(0.34)
        ).cgColor
        segment.containerLayer.backgroundColor = (isActive
            ? accentTintedWindowBackground(fraction: 0.10, alpha: 0.94)
            : spaceColor(for: segment.space)
        ).cgColor
        segment.containerLayer.shadowOpacity = isActive ? 0.26 : isCurrent ? 0.14 : 0
        segment.containerLayer.shadowRadius = isActive ? 24 : isCurrent ? 12 : 0
        segment.containerLayer.shadowOffset = CGSize(width: 0, height: isActive ? -6 : isCurrent ? -2.5 : 0)
        segment.containerLayer.zPosition = isActive ? 30 : isCurrent ? 10 : 0
        segment.containerLayer.transform = isActive
            ? CATransform3DMakeScale(1.03, 1.03, 1)
            : CATransform3DIdentity
        segment.containerLayer.shadowPath = CGPath(
            roundedRect: segment.containerLayer.bounds,
            cornerWidth: segment.containerLayer.cornerRadius,
            cornerHeight: segment.containerLayer.cornerRadius,
            transform: nil
        if isLocked {
            applySpaceLaneSolidFill(
                to: segment.containerLayer,
                color: spaceLaneLockedFillColor
            )
        } else if !hasWindows {
            applySpaceLaneSolidFill(to: segment.containerLayer, color: .clear)
        } else if isActive {
            applySpaceLaneSolidFill(
                to: segment.containerLayer,
                color: accentTintedWindowBackground(fraction: 0.10, alpha: 0.94)
            )
        } else if isAssociated {
            applySpaceLaneSolidFill(
                to: segment.containerLayer,
                color: accentTintedWindowBackground(fraction: 0.07, alpha: 0.90)
            )
        } else if hasWindows {
            applySpaceLaneGradientFill(
                to: segment.containerLayer,
                colors: spaceLaneIdleOccupiedGradientColors()
            )
        }
        segment.containerLayer.shadowColor = isLocked
            ? NSColor.white.withAlphaComponent(0.98).cgColor
            : NSColor.black.cgColor
        segment.containerLayer.shadowOpacity = (hasWindows || isLocked)
            ? (isLocked ? 0.72 : isActive ? 0.26 : isAssociated ? 0.18 : isCurrent ? 0.14 : 0)
            : 0
        segment.containerLayer.shadowRadius = (hasWindows || isLocked)
            ? (isLocked ? 30 : isActive ? 24 : isAssociated ? 18 : isCurrent ? 12 : 0)
            : 0
        segment.containerLayer.shadowOffset = CGSize(
            width: 0,
            height: (hasWindows || isLocked) ? (isLocked ? 0 : isActive ? -6 : isAssociated ? -4 : isCurrent ? -2.5 : 0) : 0
        )
        segment.containerLayer.zPosition = isLocked ? 42 : isActive ? 30 : isAssociated ? 18 : isCurrent ? 10 : 0
        segment.containerLayer.transform = (isActive || isAssociated)
            ? CATransform3DMakeScale(isActive ? 1.03 : 1.015, isActive ? 1.03 : 1.015, 1)
            : CATransform3DIdentity
        segment.containerLayer.shadowPath = (hasWindows || isLocked)
            ? CGPath(
                roundedRect: segment.containerLayer.bounds,
                cornerWidth: segment.containerLayer.cornerRadius,
                cornerHeight: segment.containerLayer.cornerRadius,
                transform: nil
            )
            : nil
        applySpaceLaneContentVisualState(segment, isLocked: isLocked)
    }
    private func applySpaceLaneContentVisualState(_ segment: SpaceLaneSegmentLayers, isLocked: Bool) {
        let primaryTextColor: NSColor = isLocked ? .white : .labelColor
        let secondaryTextColor: NSColor = isLocked
            ? .white
            : .secondaryLabelColor
        segment.labelLayer.foregroundColor = primaryTextColor.cgColor
        segment.countLayer.foregroundColor = (isLocked ? NSColor.white : .secondaryLabelColor).cgColor
        segment.appLayer.foregroundColor = (segment.space.type == .fullscreen
            ? primaryTextColor
            : secondaryTextColor
        ).cgColor
        for splitAppLayer in segment.splitAppLayers {
            splitAppLayer.foregroundColor = primaryTextColor.cgColor
        }
        for block in segment.windowBlocks {
            block.backgroundColor = (isLocked
                ? NSColor.white
                : spaceLaneOccupiedColor.withAlphaComponent(segment.space.isCurrent ? 0.72 : 0.58)
            ).cgColor
        }
        (segment.fullscreenMarkerLayer as? CAShapeLayer)?.strokeColor = (isLocked
            ? NSColor.white
            : NSColor.secondaryLabelColor.withAlphaComponent(segment.space.isCurrent ? 0.42 : 0.28)
        ).cgColor
    }
    private func shouldScrollSpaceLane(for event: NSEvent) -> Bool {
@@ -1944,13 +3009,41 @@
            y: locationInView.y - glassLayer.frame.minY - laneLayer.frame.minY - spaceLaneContentLayer.frame.minY
        )
        return spaceLaneSegments.first { segment in
            segment.containerLayer.frame.contains(locationInSpaceLaneContent)
        for group in spaceLaneDisplayGroups where group.containerLayer.frame.contains(locationInSpaceLaneContent) {
            let locationInGroup = CGPoint(
                x: locationInSpaceLaneContent.x - group.containerLayer.frame.minX,
                y: locationInSpaceLaneContent.y - group.containerLayer.frame.minY
            )
            if let segment = group.segments.first(where: { $0.containerLayer.frame.contains(locationInGroup) }) {
                return segment
            }
        }
        return nil
    }
    private func spaceLaneSegment(spaceID: UInt64) -> SpaceLaneSegmentLayers? {
        spaceLaneSegments.first { $0.space.id == spaceID }
    }
    private func settingsButtonContains(windowLocation: CGPoint) -> Bool {
        let locationInView = convert(windowLocation, from: nil)
        let locationInGlass = CGPoint(
            x: locationInView.x - glassLayer.frame.minX,
            y: locationInView.y - glassLayer.frame.minY
        )
        return settingsButtonLayer.frame.contains(locationInGlass)
    }
    private func clickSettingsButton(source: String) {
        DevelopmentDiagnostics.log("quickSwitch.view.clickSettings", [
            "source": source
        ])
        lastMouseCommand = "click-settings"
        if !mouseCommandsApplied.contains("click-settings") {
            mouseCommandsApplied.append("click-settings")
        }
        onOpenSettings?()
    }
    private func appShelfItem(at windowLocation: CGPoint) -> AppShelfItemLayers? {
@@ -1998,17 +3091,45 @@
        segment.countLayer.frame = CGRect(x: bounds.width - 34, y: bounds.height - 29, width: 24, height: 20)
        if segment.space.type == .fullscreen {
            let markerFrame = fullscreenMarkerFrame(in: bounds)
            segment.appLayer.frame = CGRect(
                x: 8,
                y: markerFrame.midY - 8.5,
                width: max(1, bounds.width - 16),
                height: 17
            )
            let splitAppNames = splitViewAppNames(for: segment.space)
            segment.appLayer.isHidden = splitAppNames.count >= 2
            if splitAppNames.count >= 2 {
                let labelY = markerFrame.midY - 8.5
                let halfWidth = markerFrame.width / 2
                for (index, splitAppLayer) in segment.splitAppLayers.enumerated() {
                    let x = markerFrame.minX + CGFloat(index) * halfWidth
                    splitAppLayer.isHidden = false
                    splitAppLayer.frame = CGRect(
                        x: x + 4,
                        y: labelY,
                        width: max(1, halfWidth - 8),
                        height: 17
                    )
                }
            } else {
                segment.appLayer.frame = CGRect(
                    x: 8,
                    y: markerFrame.midY - 8.5,
                    width: max(1, bounds.width - 16),
                    height: 17
                )
                for splitAppLayer in segment.splitAppLayers {
                    splitAppLayer.isHidden = true
                }
            }
        } else {
            segment.appLayer.isHidden = false
            segment.appLayer.frame = CGRect(x: 10, y: 9, width: max(1, bounds.width - 20), height: 17)
            for splitAppLayer in segment.splitAppLayers {
                splitAppLayer.isHidden = true
            }
        }
        if let fullscreenMarkerLayer = segment.fullscreenMarkerLayer {
            layoutFullscreenMarkerLayer(fullscreenMarkerLayer, in: bounds)
            layoutFullscreenMarkerLayer(
                fullscreenMarkerLayer,
                in: bounds,
                isSplitView: splitViewAppNames(for: segment.space).count >= 2
            )
        }
        let blockGap: CGFloat = 5
@@ -2069,8 +3190,8 @@
    private func layoutAppShelfItemContents(_ item: AppShelfItemLayers, iconSize: CGFloat) {
        let bounds = item.containerLayer.bounds
        let isSelected = item.item.appGroupIndex == effectiveSelection?.appGroupIndex
        let showsSelectedVisual = shouldShowSelectedVisual(isSelected)
        let isHovered = item.item.appGroupIndex == effectiveHoveredAppGroupIndex
        let showsSelectedVisual = shouldShowSelectedVisual(isSelected: isSelected, isHovered: isHovered)
        let isSpaceFocused = spaceFocusWindowCount(for: item.item.appGroupIndex) > 0
        let visualIconSize = appShelfVisualIconSize(
            forBaseIconSize: iconSize,
@@ -2174,15 +3295,52 @@
    }
    private var activeSpaceFocusID: UInt64? {
        hoveredSpaceLaneID
        guard case .space(let spaceID) = hoverTarget else { return nil }
        if hoverTargetSource == .debug {
            return spaceID
        }
        guard let window else { return nil }
        let currentMouseLocation = window.mouseLocationOutsideOfEventStream
        guard let segment = spaceLaneSegment(at: currentMouseLocation),
              segment.space.id == spaceID
        else {
            return nil
        }
        return spaceID
    }
    private var appHoverAssociatedSpaceIDs: Set<UInt64> {
        guard case .app(let appGroupIndex) = hoverTarget else { return [] }
        return Set(
            waterfallColumns
                .first { $0.column.appGroupIndex == appGroupIndex }?
                .cards
                .compactMap(\.item.primarySpaceID) ?? []
        )
    }
    private var appHoverAssociatedSpaceLabels: [String] {
        guard !appHoverAssociatedSpaceIDs.isEmpty else { return [] }
        return currentViewModel?.displays
            .flatMap(\.spaces)
            .filter { appHoverAssociatedSpaceIDs.contains($0.id) }
            .map(\.label)
            .sorted() ?? []
    }
    private var windowHoverAssociatedSpaceID: UInt64? {
        guard case .window(_, _, let spaceID) = hoverTarget else { return nil }
        return spaceID
    }
    private var isSpaceAssociationActive: Bool {
        activeSpaceFocusID != nil
    }
    private func shouldShowSelectedVisual(_ isSelected: Bool) -> Bool {
        isSelected && !isSpaceAssociationActive
    private func shouldShowSelectedVisual(isSelected: Bool, isHovered: Bool) -> Bool {
        isSelected && isHovered && !isSpaceAssociationActive
    }
    private func spaceFocusedAppGroupIndexes() -> [Int] {
@@ -2227,6 +3385,10 @@
              let column = waterfallColumns.first(where: { $0.column.appGroupIndex == appGroupIndex })
        else {
            return "none"
        }
        guard !isHorizontalMasonryMode else {
            return "visible"
        }
        let visibleMinX = waterfallScrollOffset
@@ -2311,17 +3473,24 @@
    }
    private func layoutWaterfallColumns() {
        if isHorizontalMasonryMode {
            layoutHorizontalMasonryWaterfall()
            return
        }
        guard !waterfallColumns.isEmpty else {
            waterfallContentWidth = waterfallLayer.bounds.width
            waterfallScrollOffset = 0
            horizontalMasonryContentHeight = waterfallLayer.bounds.height
            horizontalMasonryScrollOffset = 0
            waterfallContentLayer.frame = waterfallLayer.bounds
            return
        }
        let columnWidth = waterfallColumnWidth()
        let totalWidth = WaterfallMetrics.columnPadding * 2
            + CGFloat(waterfallColumns.count) * columnWidth
        let columnsWidth = CGFloat(waterfallColumns.count) * columnWidth
            + CGFloat(max(0, waterfallColumns.count - 1)) * WaterfallMetrics.gap
        let totalWidth = WaterfallMetrics.contentHorizontalPadding * 2 + columnsWidth
        waterfallContentWidth = max(waterfallLayer.bounds.width, totalWidth)
        waterfallScrollOffset = clampedWaterfallAlignmentOffset(waterfallScrollOffset)
        waterfallContentLayer.frame = CGRect(
@@ -2331,7 +3500,7 @@
            height: waterfallLayer.bounds.height
        )
        var x = WaterfallMetrics.columnPadding
        var x = waterfallColumnStartX(columnsWidth: columnsWidth)
        for column in waterfallColumns {
            column.containerLayer.frame = CGRect(
                x: x,
@@ -2344,9 +3513,177 @@
        }
    }
    private func layoutHorizontalMasonryWaterfall() {
        guard !waterfallColumns.isEmpty else {
            waterfallContentWidth = waterfallLayer.bounds.width
            waterfallScrollOffset = 0
            horizontalMasonryContentHeight = waterfallLayer.bounds.height
            horizontalMasonryScrollOffset = 0
            waterfallContentLayer.frame = waterfallLayer.bounds
            return
        }
        let layout = horizontalMasonryLayout()
        waterfallContentWidth = waterfallLayer.bounds.width
        waterfallScrollOffset = 0
        horizontalMasonryContentHeight = layout.contentHeight
        horizontalMasonryScrollOffset = clampedHorizontalMasonryOffset(horizontalMasonryScrollOffset)
        waterfallContentLayer.frame = horizontalMasonryContentFrame()
        for column in waterfallColumns {
            column.containerLayer.frame = CGRect(
                x: 0,
                y: 0,
                width: waterfallContentWidth,
                height: horizontalMasonryContentHeight
            )
            column.containerLayer.masksToBounds = false
            column.containerLayer.backgroundColor = NSColor.clear.cgColor
            column.containerLayer.borderColor = NSColor.clear.cgColor
            column.containerLayer.borderWidth = 0
            column.containerLayer.shadowOpacity = 0
            column.containerLayer.shadowRadius = 0
            column.containerLayer.shadowOffset = .zero
            column.headerLayer.isHidden = true
            column.appNameLayer.isHidden = true
            column.countLayer.isHidden = true
            for card in column.cards {
                if let frame = layout.cardFramesByWindowID[card.item.window.id] {
                    card.containerLayer.frame = frame
                } else {
                    card.containerLayer.frame = .zero
                }
                layoutWaterfallCard(card)
            }
        }
    }
    private struct HorizontalMasonryLayout {
        let contentHeight: CGFloat
        let cardFramesByWindowID: [UInt32: CGRect]
    }
    private func horizontalMasonryLayout() -> HorizontalMasonryLayout {
        let cards = horizontalMasonryCardsInPlacementOrder()
        guard !cards.isEmpty else {
            return HorizontalMasonryLayout(
                contentHeight: waterfallLayer.bounds.height,
                cardFramesByWindowID: [:]
            )
        }
        let viewportWidth = max(1, waterfallLayer.bounds.width)
        let availableWidth = max(
            HorizontalMasonryMetrics.cardMinWidth,
            viewportWidth - HorizontalMasonryMetrics.horizontalPadding * 2
        )
        let maximumLaneCount = max(
            1,
            Int(
                floor(
                    (availableWidth + HorizontalMasonryMetrics.horizontalGap)
                        / (HorizontalMasonryMetrics.cardMinWidth + HorizontalMasonryMetrics.horizontalGap)
                )
            )
        )
        let laneCount = min(maximumLaneCount, max(1, cards.count))
        let fittingWidth = (
            availableWidth - CGFloat(max(0, laneCount - 1)) * HorizontalMasonryMetrics.horizontalGap
        ) / CGFloat(laneCount)
        let cardWidth = floor(
            min(
                HorizontalMasonryMetrics.cardMaxWidth,
                max(HorizontalMasonryMetrics.cardMinWidth, fittingWidth)
            )
        )
        let usedWidth = CGFloat(laneCount) * cardWidth
            + CGFloat(max(0, laneCount - 1)) * HorizontalMasonryMetrics.horizontalGap
        let startX = max(
            HorizontalMasonryMetrics.horizontalPadding,
            (viewportWidth - usedWidth) / 2
        )
        var laneHeights = Array(repeating: CGFloat(0), count: laneCount)
        var plannedFrames: [(windowID: UInt32, x: CGFloat, top: CGFloat, width: CGFloat, height: CGFloat)] = []
        for card in cards {
            let laneIndex = laneHeights.enumerated().min { lhs, rhs in
                if abs(lhs.element - rhs.element) > 0.5 {
                    return lhs.element < rhs.element
                }
                return lhs.offset < rhs.offset
            }?.offset ?? 0
            let cardHeight = HorizontalMasonryMetrics.cardHeight
            let x = startX + CGFloat(laneIndex) * (cardWidth + HorizontalMasonryMetrics.horizontalGap)
            let top = HorizontalMasonryMetrics.verticalPadding + laneHeights[laneIndex]
            plannedFrames.append((
                windowID: card.item.window.id,
                x: x,
                top: top,
                width: cardWidth,
                height: cardHeight
            ))
            laneHeights[laneIndex] += cardHeight + HorizontalMasonryMetrics.verticalGap
        }
        let tallestLane = laneHeights.max().map {
            max(0, $0 - HorizontalMasonryMetrics.verticalGap)
        } ?? 0
        let contentHeight = max(
            waterfallLayer.bounds.height,
            HorizontalMasonryMetrics.verticalPadding * 2 + tallestLane
        )
        let frames = Dictionary(
            uniqueKeysWithValues: plannedFrames.map { planned in
                (
                    planned.windowID,
                    CGRect(
                        x: planned.x,
                        y: contentHeight - planned.top - planned.height,
                        width: planned.width,
                        height: planned.height
                    )
                )
            }
        )
        return HorizontalMasonryLayout(contentHeight: contentHeight, cardFramesByWindowID: frames)
    }
    private func horizontalMasonryContentFrame() -> CGRect {
        let contentHeight = max(waterfallLayer.bounds.height, horizontalMasonryContentHeight)
        return CGRect(
            x: 0,
            y: waterfallLayer.bounds.height - contentHeight + horizontalMasonryScrollOffset,
            width: waterfallLayer.bounds.width,
            height: contentHeight
        )
    }
    private func waterfallColumnStartX(columnsWidth: CGFloat) -> CGFloat {
        guard currentViewModel?.lockedSpaceID != nil else {
            return WaterfallMetrics.contentHorizontalPadding
        }
        let centeredStart = (waterfallContentWidth - columnsWidth) / 2
        return max(WaterfallMetrics.contentHorizontalPadding, centeredStart)
    }
    private func layoutWaterfallColumn(_ column: WaterfallColumnLayers) {
        column.containerLayer.cornerRadius = 14
        column.containerLayer.masksToBounds = true
        column.containerLayer.backgroundColor = NSColor.controlBackgroundColor.withAlphaComponent(0.56).cgColor
        column.containerLayer.shadowOpacity = 0
        column.containerLayer.shadowRadius = 0
        column.containerLayer.shadowOffset = .zero
        column.headerLayer.isHidden = false
        column.appNameLayer.isHidden = false
        column.countLayer.isHidden = false
        let bounds = column.containerLayer.bounds
        let isSpaceFocused = spaceFocusWindowCount(for: column.column.appGroupIndex) > 0
        let isHovered = column.column.appGroupIndex == effectiveHoveredAppGroupIndex
        column.containerLayer.borderColor = (isSpaceFocused
            ? NSColor.separatorColor.withAlphaComponent(0.38)
            : NSColor.separatorColor.withAlphaComponent(0.24)
@@ -2363,11 +3700,15 @@
            : NSColor.controlBackgroundColor.withAlphaComponent(0.52)
        ).cgColor
        column.appNameLayer.frame = CGRect(
            x: WaterfallMetrics.columnPadding,
            x: WaterfallMetrics.columnHeaderTextInset,
            y: bounds.height - 24,
            width: max(1, bounds.width - 64),
            width: max(1, bounds.width - WaterfallMetrics.columnHeaderTextInset * 2),
            height: 16
        )
        column.appNameLayer.foregroundColor = (isHovered
            ? spaceLaneOccupiedColor
            : NSColor.labelColor
        ).cgColor
        column.countLayer.frame = CGRect(
            x: bounds.width - 48,
            y: bounds.height - 24,
@@ -2382,10 +3723,10 @@
        )
        waterfallColumnScrollOffsets[appGroupIndex] = verticalOffset
        let cardWidth = max(1, bounds.width - WaterfallMetrics.columnPadding * 2)
        let cardWidth = max(1, bounds.width - WaterfallMetrics.columnHorizontalPadding * 2)
        let firstCardTop = bounds.height
            - WaterfallMetrics.headerHeight
            - WaterfallMetrics.columnPadding
            - WaterfallMetrics.columnVerticalPadding
            + verticalOffset
        for card in column.cards {
@@ -2394,7 +3735,7 @@
                - WaterfallMetrics.cardHeight
                - CGFloat(cardIndex) * (WaterfallMetrics.cardHeight + WaterfallMetrics.cardGap)
            card.containerLayer.frame = CGRect(
                x: WaterfallMetrics.columnPadding,
                x: WaterfallMetrics.columnHorizontalPadding,
                y: y,
                width: cardWidth,
                height: WaterfallMetrics.cardHeight
@@ -2407,9 +3748,13 @@
        let bounds = card.containerLayer.bounds
        let isSelected = card.item.window.id == effectiveSelection?.windowID
        let isHovered = card.item.window.id == hoveredWindowID
        applyWaterfallCardVisualState(card, selected: shouldShowSelectedVisual(isSelected), hovered: isHovered)
        applyWaterfallCardVisualState(
            card,
            selected: shouldShowSelectedVisual(isSelected: isSelected, isHovered: isHovered),
            hovered: isHovered
        )
        let outerInset: CGFloat = 8
        let outerInset: CGFloat = 0
        let titleBarHeight: CGFloat = 26
        let titleGap: CGFloat = 6
        let titleBarFrame = CGRect(
@@ -2470,7 +3815,7 @@
    }
    private func applyWaterfallCardVisualState(_ card: WaterfallCardLayers, selected: Bool, hovered: Bool) {
        let isSpaceFocused = card.item.primarySpaceID == activeSpaceFocusID
        let isSpaceFocused = isWaterfallCardSpaceFocused(card)
        card.containerLayer.backgroundColor = (selected
            ? NSColor.windowBackgroundColor.withAlphaComponent(0.94)
            : hovered
@@ -2527,13 +3872,14 @@
        let size: CGFloat = isButtonHovered ? 24 : 18
        let buttonFill = isButtonHovered
            ? NSColor.systemRed.withAlphaComponent(0.94)
            : NSColor.labelColor.withAlphaComponent(0.24)
            : NSColor.white.withAlphaComponent(0.34)
        let buttonStroke = isButtonHovered
            ? NSColor.white.withAlphaComponent(0.76)
            : NSColor.white.withAlphaComponent(0.52)
            : NSColor.white.withAlphaComponent(0.46)
        let glyphStroke = isButtonHovered
            ? NSColor.white
            : NSColor.secondaryLabelColor.withAlphaComponent(0.92)
            : NSColor.white.withAlphaComponent(0.88)
        button.containerLayer.frame = CGRect(
            x: anchorTopRight.x - size / 2,
            y: anchorTopRight.y - size / 2,
@@ -2545,10 +3891,10 @@
        button.containerLayer.borderColor = buttonStroke.cgColor
        button.containerLayer.opacity = visible ? 1 : 0
        button.containerLayer.zPosition = isButtonHovered ? 80 : 60
        button.containerLayer.shadowOpacity = visible ? (isButtonHovered ? 0.22 : 0.07) : 0
        button.containerLayer.shadowOpacity = visible ? (isButtonHovered ? 0.22 : 0.04) : 0
        button.containerLayer.shadowRadius = isButtonHovered ? 9 : 5
        button.glyphLayer.frame = CGRect(x: 0, y: 0, width: size, height: size)
        button.glyphLayer.lineWidth = isButtonHovered ? 2.1 : 1.7
        button.glyphLayer.lineWidth = isButtonHovered ? 2.1 : 1.45
        button.glyphLayer.strokeColor = glyphStroke.cgColor
        button.glyphLayer.path = closeGlyphPath(size: size, hovered: isButtonHovered)
    }
@@ -2641,6 +3987,80 @@
        layers.confirmButtonTextLayer.frame = layers.confirmButtonLayer.bounds.insetBy(dx: 0, dy: 7)
    }
    private func setCloseFeedback(_ feedback: CloseFeedback, autoHideAfter delay: TimeInterval?) {
        closeFeedbackHideTask?.cancel()
        closeFeedback = feedback
        closeFeedbackLayer.isHidden = false
        closeFeedbackLayer.opacity = 1
        closeFeedbackTextLayer.string = feedback.message
        switch feedback.kind {
        case .progress:
            closeFeedbackLayer.backgroundColor = NSColor.windowBackgroundColor.withAlphaComponent(0.94).cgColor
            closeFeedbackLayer.borderColor = NSColor.separatorColor.withAlphaComponent(0.28).cgColor
            closeFeedbackTextLayer.foregroundColor = NSColor.secondaryLabelColor.withAlphaComponent(0.96).cgColor
        case .failure:
            closeFeedbackLayer.backgroundColor = NSColor.systemRed.withAlphaComponent(0.10).cgColor
            closeFeedbackLayer.borderColor = NSColor.systemRed.withAlphaComponent(0.32).cgColor
            closeFeedbackTextLayer.foregroundColor = NSColor.systemRed.withAlphaComponent(0.95).cgColor
        }
        needsLayout = true
        guard let delay else {
            closeFeedbackHideTask = nil
            return
        }
        closeFeedbackHideTask = Task { @MainActor [weak self] in
            try? await Task.sleep(nanoseconds: UInt64(delay * 1_000_000_000))
            guard !Task.isCancelled,
                  let self,
                  self.closeFeedback == feedback
            else {
                return
            }
            self.clearCloseFeedback()
        }
    }
    private func layoutCloseFeedback() {
        guard let feedback = closeFeedback else {
            closeFeedbackLayer.isHidden = true
            closeFeedbackLayer.opacity = 0
            return
        }
        closeFeedbackLayer.isHidden = false
        closeFeedbackLayer.opacity = 1
        let font = NSFont.systemFont(
            ofSize: 13,
            weight: feedback.kind == .failure ? .medium : .regular
        )
        closeFeedbackTextLayer.font = font
        closeFeedbackTextLayer.fontSize = 13
        let textWidth = (feedback.message as NSString).size(
            withAttributes: [.font: font]
        ).width
        let maxWidth = max(180, glassLayer.bounds.width - 48)
        let width = min(max(180, textWidth + 34), min(460, maxWidth))
        let height: CGFloat = 34
        let x = max(24, (glassLayer.bounds.width - width) / 2)
        let preferredY = waterfallLayer.frame.maxY - height - 14
        let y = min(
            max(16, preferredY),
            max(16, glassLayer.bounds.height - height - 16)
        )
        closeFeedbackLayer.frame = CGRect(x: x, y: y, width: width, height: height)
        closeFeedbackLayer.cornerRadius = height / 2
        closeFeedbackLayer.shadowPath = CGPath(
            roundedRect: closeFeedbackLayer.bounds,
            cornerWidth: closeFeedbackLayer.cornerRadius,
            cornerHeight: closeFeedbackLayer.cornerRadius,
            transform: nil
        )
        closeFeedbackTextLayer.frame = closeFeedbackLayer.bounds.insetBy(dx: 17, dy: 8)
    }
    private func closeConfirmationBubblePath(
        bounds: CGRect,
        contentFrame: CGRect,
@@ -2726,18 +4146,23 @@
        }
        pendingCloseTarget = nil
        pendingCloseRequest = nil
        pendingCloseOptOut = false
        closeConfirmationLayers.containerLayer.isHidden = true
        closeConfirmationArrowEdge = nil
        if pendingCloseOptOut {
            onCloseConfirmationDisabled?()
        }
        onRequestClose?(request)
    }
    private func beginCloseConfirmation(for target: CloseTarget) {
        if closeConfirmationRequired {
            guard let request = closeRequest(for: target) else {
                DevelopmentDiagnostics.log("quickSwitch.view.closeConfirmation.missingRequest", [
                    "targetKind": target.kindDescription
                ])
                return
            }
            pendingCloseTarget = target
            pendingCloseRequest = request
            pendingCloseOptOut = false
            DevelopmentDiagnostics.log("quickSwitch.view.closeConfirmation.show", [
                "targetKind": target.kindDescription
@@ -2750,23 +4175,30 @@
    }
    private func confirmPendingClose() {
        guard let target = pendingCloseTarget else { return }
        guard let target = pendingCloseTarget,
              let request = pendingCloseRequest
        else { return }
        let shouldDisableConfirmation = pendingCloseOptOut
        pendingCloseTarget = nil
        pendingCloseRequest = nil
        pendingCloseOptOut = false
        closeConfirmationLayers.containerLayer.isHidden = true
        closeConfirmationArrowEdge = nil
        if shouldDisableConfirmation {
        if shouldDisableConfirmation && closeConfirmationRequired {
            closeConfirmationRequired = false
            onCloseConfirmationDisabled?()
        }
        if let request = closeRequest(for: target) {
            onRequestClose?(request)
        }
        DevelopmentDiagnostics.log("quickSwitch.view.closeConfirmation.confirm", [
            "targetKind": target.kindDescription,
            "disableFutureConfirmation": shouldDisableConfirmation
        ])
        onRequestClose?(request)
    }
    private func cancelPendingClose() {
        DevelopmentDiagnostics.log("quickSwitch.view.closeConfirmation.cancel")
        pendingCloseTarget = nil
        pendingCloseRequest = nil
        pendingCloseOptOut = false
        closeConfirmationLayers.containerLayer.isHidden = true
        closeConfirmationArrowEdge = nil
@@ -2774,7 +4206,15 @@
    }
    private func toggleCloseConfirmationOptOut() {
        if pendingCloseOptOut && !closeConfirmationRequired {
            return
        }
        pendingCloseOptOut.toggle()
        if pendingCloseOptOut {
            closeConfirmationRequired = false
            onCloseConfirmationDisabled?()
            DevelopmentDiagnostics.log("quickSwitch.view.closeConfirmation.optOutPersisted")
        }
        needsLayout = true
    }
@@ -2941,13 +4381,18 @@
        return color.withAlphaComponent(alpha)
    }
    private func isWaterfallCardSpaceFocused(_ card: WaterfallCardLayers) -> Bool {
        guard let activeSpaceFocusID else { return false }
        return card.item.primarySpaceID == activeSpaceFocusID
    }
    private func waterfallColumnWidth() -> CGFloat {
        guard waterfallColumns.count > 0 else { return WaterfallMetrics.columnWidth }
        let visibleColumns = min(4, max(1, waterfallColumns.count))
        let fittingWidth = (
            waterfallLayer.bounds.width
                - WaterfallMetrics.columnPadding * 2
                - WaterfallMetrics.contentHorizontalPadding * 2
                - CGFloat(max(0, visibleColumns - 1)) * WaterfallMetrics.gap
        ) / CGFloat(visibleColumns)
        return max(
@@ -2956,15 +4401,30 @@
        )
    }
    private var isHorizontalMasonryMode: Bool {
        waterfallViewMode == .horizontalMasonry
    }
    private var waterfallMaxScrollOffset: CGFloat {
        max(0, waterfallContentWidth - waterfallLayer.bounds.width)
        guard !isHorizontalMasonryMode else { return 0 }
        return max(0, waterfallContentWidth - waterfallLayer.bounds.width)
    }
    private func clampedWaterfallOffset(_ offset: CGFloat) -> CGFloat {
        min(max(0, offset), waterfallMaxScrollOffset)
    }
    private var horizontalMasonryMaxScrollOffset: CGFloat {
        max(0, horizontalMasonryContentHeight - waterfallLayer.bounds.height)
    }
    private func clampedHorizontalMasonryOffset(_ offset: CGFloat) -> CGFloat {
        min(max(0, offset), horizontalMasonryMaxScrollOffset)
    }
    private func waterfallMaxVerticalScrollOffset(for appGroupIndex: Int) -> CGFloat {
        guard !isHorizontalMasonryMode else { return 0 }
        guard
            let column = waterfallColumns.first(where: { $0.column.appGroupIndex == appGroupIndex })
        else {
@@ -2975,7 +4435,7 @@
            1,
            waterfallLayer.bounds.height
                - WaterfallMetrics.headerHeight
                - WaterfallMetrics.columnPadding * 2
                - WaterfallMetrics.columnVerticalPadding * 2
        )
        let contentHeight = CGFloat(column.cards.count) * WaterfallMetrics.cardHeight
            + CGFloat(max(0, column.cards.count - 1)) * WaterfallMetrics.cardGap
@@ -3005,15 +4465,51 @@
        return states.joined(separator: " / ")
    }
    private func spaceColor(for space: QuickSwitchSpaceViewModel) -> NSColor {
        if space.isCurrent {
            return NSColor.windowBackgroundColor.withAlphaComponent(0.76)
        }
        if space.windowCount > 0 {
            return NSColor.controlBackgroundColor.withAlphaComponent(0.56)
    private var spaceLaneOccupiedColor: NSColor {
        if effectiveAppearance.bestMatch(from: [.darkAqua, .aqua]) == .darkAqua {
            return NSColor(calibratedRed: 10 / 255, green: 132 / 255, blue: 1, alpha: 1)
        }
        return NSColor.controlBackgroundColor.withAlphaComponent(0.26)
        return NSColor(calibratedRed: 0, green: 122 / 255, blue: 1, alpha: 1)
    }
    private var spaceLaneLockedFillColor: NSColor {
        if effectiveAppearance.bestMatch(from: [.darkAqua, .aqua]) == .darkAqua {
            return NSColor(calibratedRed: 58 / 255, green: 148 / 255, blue: 1, alpha: 0.86)
        }
        return NSColor(calibratedRed: 90 / 255, green: 171 / 255, blue: 1, alpha: 0.82)
    }
    private func spaceLaneIdleOccupiedGradientColors() -> [NSColor] {
        if effectiveAppearance.bestMatch(from: [.darkAqua, .aqua]) == .darkAqua {
            let blue = NSColor(calibratedRed: 36 / 255, green: 54 / 255, blue: 72 / 255, alpha: 1)
            let surface = NSColor.windowBackgroundColor.withAlphaComponent(1)
            return [blue, surface]
        }
        return [
            NSColor(calibratedRed: 232 / 255, green: 246 / 255, blue: 1, alpha: 1),
            NSColor.white
        ]
    }
    private func applySpaceLaneGradientFill(to layer: CALayer, colors: [NSColor]) {
        if let gradientLayer = layer as? CAGradientLayer {
            gradientLayer.colors = colors.map(\.cgColor)
            gradientLayer.locations = [0, 1]
            gradientLayer.startPoint = CGPoint(x: 0.5, y: 1.0)
            gradientLayer.endPoint = CGPoint(x: 0.5, y: 0.0)
        }
        layer.backgroundColor = NSColor.clear.cgColor
    }
    private func applySpaceLaneSolidFill(to layer: CALayer, color: NSColor) {
        if let gradientLayer = layer as? CAGradientLayer {
            gradientLayer.colors = nil
            gradientLayer.locations = nil
        }
        layer.backgroundColor = color.cgColor
    }
    private func makeFullscreenMarkerLayer(for space: QuickSwitchSpaceViewModel) -> CALayer? {
@@ -3026,6 +4522,21 @@
        shapeLayer.lineCap = .round
        shapeLayer.lineJoin = .round
        return shapeLayer
    }
    private func settingsIconImage() -> CGImage? {
        let names = [
            NSImage.Name("NSPreferencesGeneral"),
            NSImage.Name("NSAdvanced")
        ]
        for name in names {
            guard let image = NSImage(named: name) else { continue }
            var rect = CGRect(origin: .zero, size: image.size)
            if let cgImage = image.cgImage(forProposedRect: &rect, context: nil, hints: nil) {
                return cgImage
            }
        }
        return nil
    }
    private func makeTextLayer(
@@ -3179,10 +4690,9 @@
        return (0..<count).map { _ in
            let layer = CALayer()
            layer.cornerRadius = 3
            layer.backgroundColor = (space.type == .fullscreen
                ? NSColor.labelColor.withAlphaComponent(0.20)
                : NSColor.labelColor.withAlphaComponent(0.18)
            ).cgColor
            layer.backgroundColor = spaceLaneOccupiedColor
                .withAlphaComponent(space.isCurrent ? 0.72 : 0.58)
                .cgColor
            return layer
        }
    }
@@ -3206,13 +4716,44 @@
        return identifiers.joined(separator: " ")
    }
    private func layoutFullscreenMarkerLayer(_ layer: CALayer, in segmentBounds: CGRect) {
    private func splitViewAppNames(for space: QuickSwitchSpaceViewModel) -> [String] {
        guard space.type == .fullscreen else { return [] }
        let names = space.splitViewAppNames
            .prefix(2)
            .map { $0.trimmingCharacters(in: .whitespacesAndNewlines) }
            .filter { !$0.isEmpty }
        guard names.count >= 2 else { return [] }
        return names
    }
    private func layoutFullscreenMarkerLayer(
        _ layer: CALayer,
        in segmentBounds: CGRect,
        isSplitView: Bool = false
    ) {
        let markerFrame = fullscreenMarkerFrame(in: segmentBounds)
        layer.frame = markerFrame
        guard let shapeLayer = layer as? CAShapeLayer else { return }
        let bounds = shapeLayer.bounds
        if isSplitView {
            let insetBounds = bounds.insetBy(dx: 0.6, dy: 0.6)
            let radius = min(7, max(5, insetBounds.height * 0.22))
            let path = CGMutablePath()
            path.addRoundedRect(
                in: insetBounds,
                cornerWidth: radius,
                cornerHeight: radius
            )
            path.move(to: CGPoint(x: bounds.midX, y: insetBounds.minY + 1.5))
            path.addLine(to: CGPoint(x: bounds.midX, y: insetBounds.maxY - 1.5))
            shapeLayer.path = path
            return
        }
        let cornerLength = min(12, max(7, min(bounds.width, bounds.height) * 0.28))
        let path = CGMutablePath()
@@ -3236,11 +4777,18 @@
    }
    private func fullscreenMarkerFrame(in segmentBounds: CGRect) -> CGRect {
        CGRect(
        let topReserved: CGFloat = 32
        let bottomReserved: CGFloat = 16
        let availableHeight = max(20, segmentBounds.height - topReserved - bottomReserved)
        let markerHeight = min(30, max(20, availableHeight))
        let markerCenterY = bottomReserved + availableHeight * 0.5
        let markerY = max(8, min(segmentBounds.height - topReserved - markerHeight, markerCenterY - markerHeight * 0.5))
        return CGRect(
            x: 10,
            y: 30,
            y: markerY,
            width: max(1, segmentBounds.width - 20),
            height: max(1, segmentBounds.height - 58)
            height: markerHeight
        )
    }
@@ -3282,7 +4830,9 @@
                "closeButtonVisible": item.closeButton.containerLayer.opacity > 0,
                "closeButtonFrame": dictionary(from: item.closeButton.containerLayer.frame),
                "closeButtonSize": Double(item.closeButton.containerLayer.bounds.width),
                "closeButtonFillColor": colorDictionary(from: item.closeButton.containerLayer.backgroundColor)
                "closeButtonFillColor": colorDictionary(from: item.closeButton.containerLayer.backgroundColor),
                "closeButtonGlyphColor": colorDictionary(from: item.closeButton.glyphLayer.strokeColor),
                "closeButtonGlyphLineWidth": Double(item.closeButton.glyphLayer.lineWidth)
            ] as [String: Any]
        }
    }
@@ -3290,12 +4840,13 @@
    private func appShelfVisualStates(for item: AppShelfItemLayers) -> [String] {
        var states: [String] = []
        let isSelected = item.item.appGroupIndex == effectiveSelection?.appGroupIndex
        if shouldShowSelectedVisual(isSelected) {
        let isHovered = item.item.appGroupIndex == effectiveHoveredAppGroupIndex
        if shouldShowSelectedVisual(isSelected: isSelected, isHovered: isHovered) {
            states.append("selected")
        } else if isSelected {
            states.append("selectedVisualSuppressed")
        }
        if item.item.appGroupIndex == effectiveHoveredAppGroupIndex {
        if isHovered {
            states.append("hover")
        }
        if spaceFocusWindowCount(for: item.item.appGroupIndex) > 0 {
@@ -3308,21 +4859,49 @@
        return states
    }
    private func waterfallColumnVisualStates(for column: WaterfallColumnLayers) -> [String] {
        var states: [String] = []
        if column.column.appGroupIndex == effectiveHoveredAppGroupIndex {
            states.append("hover")
        }
        if spaceFocusWindowCount(for: column.column.appGroupIndex) > 0 {
            states.append("spaceFocused")
        }
        return states
    }
    private func waterfallColumnReports() -> [[String: Any]] {
        waterfallColumns.map { column in
            let visibleFrame = column.containerLayer.frame.offsetBy(dx: waterfallContentLayer.frame.minX, dy: 0)
            let appGroupIndex = column.column.appGroupIndex
            let isHovered = appGroupIndex == effectiveHoveredAppGroupIndex
            let firstCardFrame = column.cards.first?.containerLayer.frame
            let headerToFirstCardGap = firstCardFrame.map {
                column.headerLayer.frame.minY - $0.maxY
            }
            let topToFirstCardGap = firstCardFrame.map {
                column.containerLayer.bounds.height - $0.maxY
            }
            return [
                "appGroupIndex": appGroupIndex,
                "appName": column.column.app.name,
                "bundleIdentifier": column.column.app.bundleIdentifier,
                "windowCount": column.column.windows.count,
                "isHovered": isHovered,
                "visualStates": waterfallColumnVisualStates(for: column),
                "spaceFocusWindowCount": spaceFocusWindowCount(for: appGroupIndex),
                "isSpaceFocused": spaceFocusWindowCount(for: appGroupIndex) > 0,
                "spaceFocusDirection": spaceFocusDirection(for: appGroupIndex),
                "frame": dictionary(from: column.containerLayer.frame),
                "visibleFrame": dictionary(from: visibleFrame),
                "headerFrame": dictionary(from: column.headerLayer.frame),
                "headerToFirstCardGap": headerToFirstCardGap.map(Double.init) ?? NSNull(),
                "topToFirstCardGap": topToFirstCardGap.map(Double.init) ?? NSNull(),
                "appNameFrame": dictionary(from: column.appNameLayer.frame),
                "appNameAlignment": column.appNameLayer.alignmentMode.rawValue,
                "appNameColor": colorDictionary(from: column.appNameLayer.foregroundColor),
                "countFrame": dictionary(from: column.countLayer.frame),
                "verticalScrollOffset": Double(waterfallColumnScrollOffsets[appGroupIndex] ?? 0),
                "maxVerticalScrollOffset": Double(waterfallMaxVerticalScrollOffset(for: appGroupIndex)),
                "cards": waterfallCardReports(for: column)
@@ -3418,6 +4997,8 @@
                "closeButtonFrame": dictionary(from: card.closeButton.containerLayer.frame),
                "closeButtonSize": Double(card.closeButton.containerLayer.bounds.width),
                "closeButtonFillColor": colorDictionary(from: card.closeButton.containerLayer.backgroundColor),
                "closeButtonGlyphColor": colorDictionary(from: card.closeButton.glyphLayer.strokeColor),
                "closeButtonGlyphLineWidth": Double(card.closeButton.glyphLayer.lineWidth),
                "shineVisible": card.shineLayer.opacity > 0,
                "zPosition": Double(card.containerLayer.zPosition),
                "frame": dictionary(from: card.containerLayer.frame),
@@ -3513,15 +5094,16 @@
    private func waterfallCardVisualStates(for card: WaterfallCardLayers) -> [String] {
        var states: [String] = []
        let isSelected = card.item.window.id == effectiveSelection?.windowID
        if shouldShowSelectedVisual(isSelected) {
        let isHovered = card.item.window.id == hoveredWindowID
        if shouldShowSelectedVisual(isSelected: isSelected, isHovered: isHovered) {
            states.append("selected")
        } else if isSelected {
            states.append("selectedVisualSuppressed")
        }
        if card.item.window.id == hoveredWindowID {
        if isHovered {
            states.append("hover")
        }
        if card.item.primarySpaceID == activeSpaceFocusID {
        if isWaterfallCardSpaceFocused(card) {
            states.append("spaceFocused")
        }
        if card.item.window.isMinimized {
@@ -3537,32 +5119,99 @@
        window?.backingScaleFactor ?? NSScreen.main?.backingScaleFactor ?? 2
    }
    private func spaceLaneDisplayGroupReports() -> [[String: Any]] {
        spaceLaneDisplayGroups.map { group in
            let visibleFrame = group.containerLayer.frame.offsetBy(dx: spaceLaneContentLayer.frame.minX, dy: 0)
            return [
                "displayUUID": group.display.displayUUID,
                "displayIndex": group.display.displayIndex,
                "displayLabel": group.display.displayLabel,
                "physical": group.display.physical,
                "spaceCount": group.segments.count,
                "spaceIDs": group.segments.map(\.space.id),
                "spaceLabels": group.segments.map(\.space.label),
                "frame": dictionary(from: group.containerLayer.frame),
                "visibleFrame": dictionary(from: visibleFrame),
                "backgroundColor": colorDictionary(from: group.containerLayer.backgroundColor),
                "borderColor": colorDictionary(from: group.containerLayer.borderColor),
                "borderWidth": Double(group.containerLayer.borderWidth),
                "shadowOpacity": Double(group.containerLayer.shadowOpacity),
                "shadowRadius": Double(group.containerLayer.shadowRadius),
                "groupGap": Double(SpaceLaneMetrics.groupGap),
                "groupHorizontalPadding": Double(SpaceLaneMetrics.groupHorizontalPadding),
                "groupVerticalPadding": Double(SpaceLaneMetrics.groupVerticalPadding),
                "segmentGap": Double(SpaceLaneMetrics.segmentGap)
            ] as [String: Any]
        }
    }
    private func spaceLaneSegmentReports() -> [[String: Any]] {
        currentViewModel?.displays.flatMap { display in
            display.spaces.compactMap { space in
                guard let segment = spaceLaneSegments.first(where: { $0.space.id == space.id }) else {
                    return nil
                }
                let visibleFrame = segment.containerLayer.frame.offsetBy(dx: spaceLaneContentLayer.frame.minX, dy: 0)
                let isAppAssociated = appHoverAssociatedSpaceIDs.contains(space.id)
                let isWindowAssociated = space.id == windowHoverAssociatedSpaceID
                let group = spaceLaneDisplayGroup(containingSpaceID: space.id)
                let visibleFrame = segment.containerLayer.frame.offsetBy(
                    dx: (group?.containerLayer.frame.minX ?? 0) + spaceLaneContentLayer.frame.minX,
                    dy: group?.containerLayer.frame.minY ?? 0
                )
                let fullscreenMarkerFrame = segment.fullscreenMarkerLayer?.frame
                let fullscreenMarkerCenterRatio = fullscreenMarkerFrame.map {
                    Double($0.midY / max(1, segment.containerLayer.bounds.height))
                }
                let splitAppNames = splitViewAppNames(for: space)
                let splitAppLabelFrames = segment.splitAppLayers.map { dictionary(from: $0.frame) }
                return [
                    "displayUUID": display.displayUUID,
                    "displayLabel": display.displayLabel,
                    "spaceID": space.id,
                    "label": space.label,
                    "type": spaceTypeName(space.type),
                    "visualStates": visualStates(for: space),
                    "fullscreenMarkerVisible": segment.fullscreenMarkerLayer != nil,
                    "fullscreenMarkerKind": segment.fullscreenMarkerLayer == nil ? "none" : "cornerBracket",
                    "fullscreenMarkerFrame": segment.fullscreenMarkerLayer.map { dictionary(from: $0.frame) } ?? NSNull(),
                    "fullscreenMarkerKind": fullscreenMarkerKind(
                        markerLayer: segment.fullscreenMarkerLayer,
                        splitAppNames: splitAppNames
                    ),
                    "fullscreenMarkerFrame": fullscreenMarkerFrame.map { dictionary(from: $0) } ?? NSNull(),
                    "fullscreenMarkerCenterRatio": fullscreenMarkerCenterRatio ?? NSNull(),
                    "splitViewAppNames": splitAppNames,
                    "splitViewLabelFrames": splitAppLabelFrames,
                    "splitViewLabelColors": segment.splitAppLayers.map {
                        colorDictionary(from: $0.foregroundColor)
                    },
                    "windowBlockCount": segment.windowBlocks.count,
                    "windowBlockColors": segment.windowBlocks.map { colorDictionary(from: $0.backgroundColor) },
                    "windowBlockFrames": segment.windowBlocks.map { dictionary(from: $0.frame) },
                    "labelColor": colorDictionary(from: segment.labelLayer.foregroundColor),
                    "countColor": colorDictionary(from: segment.countLayer.foregroundColor),
                    "appColor": colorDictionary(from: segment.appLayer.foregroundColor),
                    "fullscreenMarkerStrokeColor": colorDictionary(
                        from: (segment.fullscreenMarkerLayer as? CAShapeLayer)?.strokeColor
                    ),
                    "backgroundKind": spaceLaneFillKind(for: segment.containerLayer),
                    "backgroundColor": colorDictionary(from: segment.containerLayer.backgroundColor),
                    "gradientColors": gradientColorDictionaries(from: segment.containerLayer),
                    "borderColor": colorDictionary(from: segment.containerLayer.borderColor),
                    "borderWidth": Double(segment.containerLayer.borderWidth),
                    "shadowColor": colorDictionary(from: segment.containerLayer.shadowColor),
                    "shadowOpacity": Double(segment.containerLayer.shadowOpacity),
                    "shadowRadius": Double(segment.containerLayer.shadowRadius),
                    "shadowOffset": [
                        "width": Double(segment.containerLayer.shadowOffset.width),
                        "height": Double(segment.containerLayer.shadowOffset.height)
                    ],
                    "appFrame": dictionary(from: segment.appLayer.frame),
                    "frame": dictionary(from: segment.containerLayer.frame),
                    "visibleFrame": dictionary(from: visibleFrame),
                    "isCurrent": space.isCurrent,
                    "isHovered": space.id == hoveredSpaceID,
                    "isHovered": space.id == activeSpaceFocusID,
                    "isFocused": space.id == activeSpaceFocusID,
                    "isAppAssociated": isAppAssociated,
                    "isWindowAssociated": isWindowAssociated,
                    "windowCount": space.windowCount,
                    "appCount": space.appCount,
                    "appNames": space.appNames
@@ -3571,19 +5220,42 @@
        } ?? []
    }
    private func spaceLaneDisplayGroup(containingSpaceID spaceID: UInt64) -> SpaceLaneDisplayGroupLayers? {
        spaceLaneDisplayGroups.first { group in
            group.segments.contains { $0.space.id == spaceID }
        }
    }
    private func fullscreenMarkerKind(markerLayer: CALayer?, splitAppNames: [String]) -> String {
        guard markerLayer != nil else { return "none" }
        return splitAppNames.count >= 2 ? "splitViewPair" : "cornerBracket"
    }
    private func visualStates(for space: QuickSwitchSpaceViewModel) -> [String] {
        var states: [String] = []
        if space.isCurrent {
            states.append("current")
        }
        if space.id == hoveredSpaceID {
        if appHoverAssociatedSpaceIDs.contains(space.id) {
            states.append("appAssociated")
        }
        if space.id == windowHoverAssociatedSpaceID {
            states.append("windowAssociated")
        }
        if space.id == activeSpaceFocusID {
            states.append("hover")
        }
        if space.id == activeSpaceFocusID {
            states.append("focused")
        }
        if space.id == currentViewModel?.lockedSpaceID {
            states.append("locked")
        }
        if space.type == .fullscreen {
            states.append("fullscreen")
        }
        if splitViewAppNames(for: space).count >= 2 {
            states.append("splitView")
        }
        return states
    }
@@ -3629,4 +5301,23 @@
            "alpha": Double(nsColor.alphaComponent)
        ]
    }
    private func gradientColorDictionaries(from layer: CALayer) -> [[String: Double]] {
        guard let gradientLayer = layer as? CAGradientLayer else { return [] }
        return (gradientLayer.colors ?? []).map { color in
            let cgColor = color as! CGColor
            return colorDictionary(from: cgColor)
        }
    }
    private func spaceLaneFillKind(for layer: CALayer) -> String {
        if !gradientColorDictionaries(from: layer).isEmpty {
            return "gradient"
        }
        let background = colorDictionary(from: layer.backgroundColor)
        if background["alpha", default: 0] <= 0.01 {
            return "clear"
        }
        return "solid"
    }
}