diff --git a/README.md b/README.md
index 3ee428a..0f2e511 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,8 @@
 # CurrentNavigation
 
-CurrentNavigation 1.0.0 ist ein SPFx-1.4.1-Application-Customizer für moderne Seiten in SharePoint Server
-Subscription Edition. Die Solution rendert im oberen Placeholder eine Navigation für das aktuelle Web.
+CurrentNavigation 1.1.0 ist ein SPFx-1.4.1-Application-Customizer für moderne Seiten in SharePoint Server
+Subscription Edition. Die Solution ersetzt die Einträge im modernen SiteNavigation-Bereich durch einen Treeview
+für das aktuelle Web. Beim Entladen der Extension wird die ursprüngliche SharePoint-Navigation wieder sichtbar.
 
 ## Term-Konfiguration
 
@@ -14,6 +15,12 @@ Die URL des Root-Terms wird mit pageContext.web.absoluteUrl verglichen. Sowohl d
 Homepage unterhalb der Web-URL werden erkannt. Der Root-Term wird standardmäßig nicht dargestellt; seine direkten
 Kinder bilden die erste Navigationsebene.
 
+Der Treeview unterstützt auf- und zuklappbare Zweige, aktive Seitenpfade sowie die Navigation mit den Pfeiltasten,
+Pos1 und Ende.
+
+Wenn kein passender Root-Term gefunden wird oder das Termset nicht geladen werden kann, bleibt die native
+SharePoint-Sitenavigation unverändert sichtbar.
+
 ## Build und Bereitstellung
 
 Voraussetzungen: Node.js 8.17.0, npm 6.x und lokales Gulp 3.9.1.
diff --git a/ToDo.md b/ToDo.md
index 7931301..b32d7c5 100644
--- a/ToDo.md
+++ b/ToDo.md
@@ -1,9 +1,11 @@
 # CurrentNavigation – Umsetzungsstand
 
-Zielversion: 1.0.0
+Zielversion: 1.1.0
 Status: Implementierung und lokale Tests abgeschlossen; Ship-Build auf Node 8 ausstehend
 
 - [x] SPFx Application Customizer für moderne Seiten
+- [x] Rendering im modernen SiteNavigation-Container statt im Top-Placeholder
+- [x] Barrierearmer Treeview mit Tastatursteuerung
 - [x] Site-Collection-weite Registrierung
 - [x] Termset-Picker über PortalSettings
 - [x] Cache-Dauer, Cache-Version und Debug-Modus
diff --git a/config/package-solution.json b/config/package-solution.json
index 7701513..9ecda25 100644
--- a/config/package-solution.json
+++ b/config/package-solution.json
@@ -3,7 +3,7 @@
   "solution": {
     "name": "current-navigation-client-side-solution",
     "id": "bb8f9af5-b318-4111-8401-ce189cfe1b1a",
-    "version": "1.0.0.0",
+    "version": "1.1.0.0",
     "includeClientSideAssets": true,
     "skipFeatureDeployment": true
   },
diff --git a/package-lock.json b/package-lock.json
index 3386dcc..0c132d5 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "current-navigation",
-  "version": "1.0.0",
+  "version": "1.1.0",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
diff --git a/package.json b/package.json
index 018ae41..2879aa0 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "current-navigation",
-  "version": "1.0.0",
+  "version": "1.1.0",
   "private": true,
   "main": "lib/index.js",
   "engines": {
diff --git a/src/extensions/currentNavigation/CurrentNavigation.module.scss b/src/extensions/currentNavigation/CurrentNavigation.module.scss
index eb702d7..27ad0a6 100644
--- a/src/extensions/currentNavigation/CurrentNavigation.module.scss
+++ b/src/extensions/currentNavigation/CurrentNavigation.module.scss
@@ -1,12 +1,16 @@
 @import '~@microsoft/sp-office-ui-fabric-core/dist/sass/SPFabricCore.scss';
 
 :global {
-  .current-navigation {
-    position: relative;
-    z-index: 299;
+  .current-navigation-managed > :not(#CurrentNavigationHost) {
+    display: none !important;
+  }
+
+  #CurrentNavigationHost {
+    width: 100%;
+  }
+
+  .current-navigation {
     width: 100%;
-    border-bottom: 1px solid $ms-color-neutralLight;
-    background: $ms-color-white;
     color: $ms-color-neutralPrimary;
     font-family: $ms-font-family-fallbacks;
     font-size: $ms-font-size-s;
@@ -18,74 +22,93 @@
     list-style: none;
   }
 
-  .current-navigation-root {
-    display: flex;
-    min-height: 40px;
-    padding: 0 16px !important;
+  .current-navigation-group {
+    padding-left: 20px !important;
   }
 
-  .current-navigation li {
-    position: relative;
-  }
-
-  .current-navigation a,
-  .current-navigation span {
+  .current-navigation-row {
     display: flex;
     align-items: center;
-    min-height: 40px;
-    padding: 0 12px;
+    min-height: 36px;
+  }
+
+  .current-navigation-toggle,
+  .current-navigation-toggle-spacer {
+    flex: 0 0 32px;
+    width: 32px;
+    height: 36px;
+  }
+
+  .current-navigation-toggle {
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    margin: 0;
+    padding: 0;
+    border: 0;
+    background: transparent;
+    color: $ms-color-neutralSecondary;
+    cursor: pointer;
+  }
+
+  .current-navigation-toggle:hover {
+    background: $ms-color-neutralLighter;
+    color: $ms-color-neutralPrimary;
+  }
+
+  .current-navigation-chevron {
+    width: 7px;
+    height: 7px;
+    border-right: 1px solid currentColor;
+    border-bottom: 1px solid currentColor;
+    transform: rotate(-45deg);
+    transition: transform 120ms ease;
+  }
+
+  .current-navigation-item[aria-expanded='true'] > .current-navigation-row .current-navigation-chevron {
+    transform: rotate(45deg);
+  }
+
+  .current-navigation-label {
+    display: flex;
+    flex: 1 1 auto;
+    align-items: center;
+    min-width: 0;
+    min-height: 36px;
+    padding: 0 12px 0 4px;
+    overflow: hidden;
     color: inherit;
     text-decoration: none;
+    text-overflow: ellipsis;
     white-space: nowrap;
   }
 
-  .current-navigation a:hover,
-  .current-navigation a:focus,
-  .current-navigation a.is-current {
-    color: $ms-color-themePrimary;
+  .current-navigation-label:hover,
+  .current-navigation-label:focus {
     background: $ms-color-neutralLighter;
+    color: $ms-color-themePrimary;
   }
 
-  .current-navigation a:focus {
+  .current-navigation-label:focus {
     outline: 2px solid $ms-color-themePrimary;
     outline-offset: -2px;
   }
 
-  .current-navigation-children {
-    position: absolute;
-    top: 100%;
-    left: 0;
+  .current-navigation-label.is-current {
+    background: $ms-color-neutralLighter;
+    color: $ms-color-themePrimary;
+    font-weight: $ms-font-weight-semibold;
+  }
+
+  .current-navigation-group[hidden] {
     display: none;
-    min-width: 220px;
-    border: 1px solid $ms-color-neutralLight;
-    background: $ms-color-white;
-    box-shadow: 0 4px 12px rgba(0, 0, 0, .16);
   }
 
-  .current-navigation-children .current-navigation-children {
-    top: 0;
-    left: 100%;
+  @media (prefers-reduced-motion: reduce) {
+    .current-navigation-chevron { transition: none; }
   }
 
-  .current-navigation li:hover > .current-navigation-children,
-  .current-navigation li:focus-within > .current-navigation-children {
-    display: block;
-  }
-
-  @media (max-width: 767px) {
-    .current-navigation-root {
-      flex-wrap: wrap;
-      padding: 0 8px !important;
-    }
-
-    .current-navigation-children,
-    .current-navigation-children .current-navigation-children {
-      position: static;
-      display: block;
-      min-width: 0;
-      border: 0;
-      box-shadow: none;
-      padding-left: 16px;
-    }
+  @media (forced-colors: active) {
+    .current-navigation-label:focus { outline: 2px solid CanvasText; }
   }
 }
diff --git a/src/extensions/currentNavigation/CurrentNavigationApplicationCustomizer.ts b/src/extensions/currentNavigation/CurrentNavigationApplicationCustomizer.ts
index 2aa41a9..22df32d 100644
--- a/src/extensions/currentNavigation/CurrentNavigationApplicationCustomizer.ts
+++ b/src/extensions/currentNavigation/CurrentNavigationApplicationCustomizer.ts
@@ -1,11 +1,8 @@
 // tslint:disable:max-line-length variable-name
 import { override } from '@microsoft/decorators';
-import { BaseApplicationCustomizer, PlaceholderContent, PlaceholderName } from '@microsoft/sp-application-base';
+import { BaseApplicationCustomizer } from '@microsoft/sp-application-base';
 import * as strings from 'CurrentNavigationApplicationCustomizerStrings';
-import {
-  buildCurrentNavigationItems,
-  selectCurrentNavigationRoot
-} from '../../services/CurrentNavigationCore';
+import { buildCurrentNavigationItems, selectCurrentNavigationRoot } from '../../services/CurrentNavigationCore';
 import { CurrentNavigationTaxonomyService } from '../../services/CurrentNavigationTaxonomyService';
 import { ICurrentNavigationItem, ICurrentNavigationTerm, ITermSetResult } from '../../services/CurrentNavigationTypes';
 import { CurrentNavigationRenderer } from './CurrentNavigationRenderer';
@@ -23,42 +20,81 @@ export interface ICurrentNavigationApplicationCustomizerProperties {
 
 export default class CurrentNavigationApplicationCustomizer
   extends BaseApplicationCustomizer<ICurrentNavigationApplicationCustomizerProperties> {
-  private topPlaceholder: PlaceholderContent | undefined;
+  private siteNavigation: HTMLElement | undefined;
   private host: HTMLElement | undefined;
+  private observer: MutationObserver | undefined;
+  private mountPending: boolean = false;
   private renderer: CurrentNavigationRenderer = new CurrentNavigationRenderer();
   private renderVersion: number = 0;
 
   @override
   public onInit(): Promise<void> {
-    this.context.placeholderProvider.changedEvent.add(this, this.renderPlaceholders);
     const application: any = this.context.application as any; // tslint:disable-line:no-any
-    if (application && application.navigatedEvent) {
-      application.navigatedEvent.add(this, this.onNavigated);
-    }
-    this.renderPlaceholders();
+    if (application && application.navigatedEvent) { application.navigatedEvent.add(this, this.onNavigated); }
+    this.observer = new MutationObserver(this.onDomChanged);
+    this.observer.observe(document.body, { childList: true, subtree: true });
+    this.mountInSiteNavigation(true);
     return Promise.resolve();
   }
 
-  private renderPlaceholders = (): void => {
-    if (!this.topPlaceholder) {
-      this.topPlaceholder = this.context.placeholderProvider.tryCreateContent(
-        PlaceholderName.Top, { onDispose: this.onPlaceholderDisposed }
-      );
-    }
-    if (!this.topPlaceholder) { return; }
-    if (!this.host) {
-      this.host = document.createElement('div');
-      this.host.id = 'CurrentNavigationHost';
-      this.topPlaceholder.domElement.appendChild(this.host);
-    }
-    this.renderNavigation();
+  private onNavigated = (): void => { this.scheduleMount(true); }
+
+  private onDomChanged = (): void => {
+    if (!this.host || !document.body.contains(this.host)) { this.scheduleMount(true); }
   }
 
-  private onNavigated = (): void => { this.renderNavigation(); }
+  private scheduleMount(forceRender: boolean): void {
+    if (this.mountPending) { return; }
+    this.mountPending = true;
+    window.setTimeout((): void => {
+      this.mountPending = false;
+      this.mountInSiteNavigation(forceRender);
+    }, 0);
+  }
+
+  private mountInSiteNavigation(forceRender: boolean): void {
+    const container: HTMLElement = this.findSiteNavigation();
+    if (!container) {
+      this.debug('The modern SiteNavigation container was not found.');
+      return;
+    }
+    if (this.siteNavigation !== container || !this.host || !container.contains(this.host)) {
+      this.detachHost();
+      this.siteNavigation = container;
+      this.host = document.createElement('div');
+      this.host.id = 'CurrentNavigationHost';
+      this.siteNavigation.appendChild(this.host);
+      forceRender = true;
+    }
+    if (forceRender) { this.renderNavigation(); }
+  }
+
+  private findSiteNavigation(): HTMLElement | undefined {
+    const selectors: string[] = [
+      '[data-automationid="SiteNavigation"]',
+      '[data-automation-id="SiteNavigation"]',
+      '#spLeftNav',
+      'nav[aria-label="Site navigation"]',
+      'nav[aria-label="Websitenavigation"]'
+    ];
+    for (let i: number = 0; i < selectors.length; i++) {
+      const candidates: NodeListOf<Element> = document.querySelectorAll(selectors[i]);
+      for (let j: number = 0; j < candidates.length; j++) {
+        const candidate: HTMLElement = candidates[j] as HTMLElement;
+        if (candidate.id !== 'CurrentNavigationHost' && !this.hostContains(candidate)) { return candidate; }
+      }
+    }
+    return undefined;
+  }
+
+  private hostContains(element: HTMLElement): boolean {
+    return !!(this.host && this.host.contains(element));
+  }
 
   private async renderNavigation(): Promise<void> {
     const version: number = ++this.renderVersion;
     if (!this.host) { return; }
+    if (this.siteNavigation) { this.siteNavigation.classList.remove('current-navigation-managed'); }
     this.renderer.clear(this.host);
     const termSetId: string = this.properties && this.properties.termSetId
       ? String(this.properties.termSetId).trim() : '';
@@ -68,8 +104,7 @@ export default class CurrentNavigationApplicationCustomizer
     }
     try {
       const service: CurrentNavigationTaxonomyService = new CurrentNavigationTaxonomyService(
-        this.context, termSetId, this.cacheMinutes(), this.cacheVersion(),
-        this.languageLcid(), this.isDebug()
+        this.context, termSetId, this.cacheMinutes(), this.cacheVersion(), this.languageLcid(), this.isDebug()
       );
       const termSet: ITermSetResult = await service.getTerms();
       if (version !== this.renderVersion || !this.host) { return; }
@@ -81,10 +116,15 @@ export default class CurrentNavigationApplicationCustomizer
         termSet.Terms, root, this.context.pageContext.site.absoluteUrl,
         this.languageLcid(), this.maxDepth(), !!(this.properties && this.properties.showRoot)
       );
-      if (items.length) { this.renderer.render(this.host, items, strings.NavigationLabel); }
-    } catch (error) {
-      this.debug(strings.LoadError, error);
-    }
+      if (items.length && this.host) {
+        if (this.siteNavigation) { this.siteNavigation.classList.add('current-navigation-managed'); }
+        this.renderer.render(this.host, items, {
+          navigationLabel: strings.NavigationLabel,
+          expand: strings.Expand,
+          collapse: strings.Collapse
+        });
+      }
+    } catch (error) { this.debug(strings.LoadError, error); }
   }
 
   private cacheMinutes(): number {
@@ -109,17 +149,22 @@ export default class CurrentNavigationApplicationCustomizer
   private debug(message: string, data?: any): void { // tslint:disable-line:no-any
     if (this.isDebug() && window.console) { console.log('[CurrentNavigation] ' + message, data || ''); }
   }
-  private onPlaceholderDisposed = (): void => {
-    if (this.host) { this.renderer.clear(this.host); }
+  private detachHost(): void {
+    this.renderVersion++;
+    if (this.host) {
+      this.renderer.clear(this.host);
+      if (this.host.parentElement) { this.host.parentElement.removeChild(this.host); }
+    }
+    if (this.siteNavigation) { this.siteNavigation.classList.remove('current-navigation-managed'); }
     this.host = undefined;
-    this.topPlaceholder = undefined;
+    this.siteNavigation = undefined;
   }
 
   @override
   protected onDispose(): void {
-    this.context.placeholderProvider.changedEvent.remove(this, this.renderPlaceholders);
     const application: any = this.context.application as any; // tslint:disable-line:no-any
     if (application && application.navigatedEvent) { application.navigatedEvent.remove(this, this.onNavigated); }
-    this.onPlaceholderDisposed();
+    if (this.observer) { this.observer.disconnect(); this.observer = undefined; }
+    this.detachHost();
   }
 }
diff --git a/src/extensions/currentNavigation/CurrentNavigationRenderer.ts b/src/extensions/currentNavigation/CurrentNavigationRenderer.ts
index 6032f8b..09c4489 100644
--- a/src/extensions/currentNavigation/CurrentNavigationRenderer.ts
+++ b/src/extensions/currentNavigation/CurrentNavigationRenderer.ts
@@ -1,41 +1,200 @@
-import { ICurrentNavigationItem } from '../../services/CurrentNavigationTypes';
 import { normalizeNavigationPath } from '../../services/CurrentNavigationCore';
+import { ICurrentNavigationItem } from '../../services/CurrentNavigationTypes';
+
+export interface ICurrentNavigationRendererStrings {
+  navigationLabel: string;
+  expand: string;
+  collapse: string;
+}
 
 export class CurrentNavigationRenderer {
-  public render(container: HTMLElement, items: ICurrentNavigationItem[], navigationLabel: string): void {
+  private container: HTMLElement | undefined;
+  private keydownHandler: ((event: KeyboardEvent) => void) | undefined;
+  private strings: ICurrentNavigationRendererStrings;
+
+  public render(
+    container: HTMLElement,
+    items: ICurrentNavigationItem[],
+    strings: ICurrentNavigationRendererStrings
+  ): void {
     this.clear(container);
+    this.container = container;
+    this.strings = strings;
     const nav: HTMLElement = document.createElement('nav');
     nav.className = 'current-navigation';
-    nav.setAttribute('aria-label', navigationLabel);
-    nav.appendChild(this.createList(items, 1));
+    nav.setAttribute('aria-label', strings.navigationLabel);
+    nav.appendChild(this.createList(items, 1, true));
+    this.keydownHandler = this.onKeydown;
+    nav.addEventListener('keydown', this.keydownHandler);
     container.appendChild(nav);
   }
 
   public clear(container: HTMLElement): void {
+    if (this.keydownHandler && this.container) {
+      const nav: HTMLElement = this.container.querySelector('.current-navigation') as HTMLElement;
+      if (nav) { nav.removeEventListener('keydown', this.keydownHandler); }
+    }
     while (container && container.firstChild) { container.removeChild(container.firstChild); }
+    this.keydownHandler = undefined;
+    this.container = undefined;
   }
 
-  private createList(items: ICurrentNavigationItem[], depth: number): HTMLUListElement {
+  private createList(items: ICurrentNavigationItem[], depth: number, root: boolean): HTMLUListElement {
     const list: HTMLUListElement = document.createElement('ul');
-    list.className = depth === 1 ? 'current-navigation-root' : 'current-navigation-children';
+    list.className = root ? 'current-navigation-tree' : 'current-navigation-group';
+    list.setAttribute('role', root ? 'tree' : 'group');
     for (let i: number = 0; i < items.length; i++) {
-      const item: ICurrentNavigationItem = items[i];
-      const entry: HTMLLIElement = document.createElement('li');
-      entry.className = item.items.length ? 'has-children' : '';
-      const content: HTMLElement = item.url ? document.createElement('a') : document.createElement('span');
-      content.textContent = item.label;
-      if (item.url) {
-        const link: HTMLAnchorElement = content as HTMLAnchorElement;
-        link.href = item.url;
-        if (normalizeNavigationPath(window.location.href) === normalizeNavigationPath(item.url)) {
-          link.setAttribute('aria-current', 'page');
-          link.className = 'is-current';
-        }
-      }
-      entry.appendChild(content);
-      if (item.items.length) { entry.appendChild(this.createList(item.items, depth + 1)); }
-      list.appendChild(entry);
+      list.appendChild(this.createItem(items[i], depth));
     }
     return list;
   }
+
+  private createItem(item: ICurrentNavigationItem, depth: number): HTMLLIElement {
+    const entry: HTMLLIElement = document.createElement('li');
+    const hasChildren: boolean = item.items.length > 0;
+    const activeBranch: boolean = this.containsCurrentItem(item);
+    entry.className = hasChildren ? 'current-navigation-item has-children' : 'current-navigation-item';
+    entry.setAttribute('role', 'treeitem');
+    entry.setAttribute('aria-level', String(depth));
+
+    const row: HTMLDivElement = document.createElement('div');
+    row.className = 'current-navigation-row';
+    if (hasChildren) {
+      const toggle: HTMLButtonElement = document.createElement('button');
+      toggle.type = 'button';
+      toggle.className = 'current-navigation-toggle';
+      toggle.tabIndex = -1;
+      toggle.setAttribute('aria-expanded', activeBranch ? 'true' : 'false');
+      toggle.setAttribute('aria-label', (activeBranch ? this.strings.collapse : this.strings.expand) + ' ' + item.label);
+      const chevron: HTMLSpanElement = document.createElement('span');
+      chevron.className = 'current-navigation-chevron';
+      chevron.setAttribute('aria-hidden', 'true');
+      toggle.appendChild(chevron);
+      toggle.addEventListener('click', (): void => {
+        this.setExpanded(entry, entry.getAttribute('aria-expanded') !== 'true', item.label);
+      });
+      row.appendChild(toggle);
+      entry.setAttribute('aria-expanded', activeBranch ? 'true' : 'false');
+    } else {
+      const spacer: HTMLSpanElement = document.createElement('span');
+      spacer.className = 'current-navigation-toggle-spacer';
+      spacer.setAttribute('aria-hidden', 'true');
+      row.appendChild(spacer);
+    }
+
+    const content: HTMLElement = item.url ? document.createElement('a') : document.createElement('span');
+    content.className = 'current-navigation-label';
+    content.textContent = item.label;
+    if (item.url) {
+      const link: HTMLAnchorElement = content as HTMLAnchorElement;
+      link.href = item.url;
+      if (this.isCurrentUrl(item.url)) {
+        link.setAttribute('aria-current', 'page');
+        link.className += ' is-current';
+      }
+    } else {
+      content.setAttribute('tabindex', '0');
+    }
+    row.appendChild(content);
+    entry.appendChild(row);
+    if (hasChildren) {
+      const children: HTMLUListElement = this.createList(item.items, depth + 1, false);
+      children.hidden = !activeBranch;
+      entry.appendChild(children);
+    }
+    return entry;
+  }
+
+  private setExpanded(entry: HTMLLIElement, expanded: boolean, label?: string): void {
+    const row: HTMLElement = entry.firstElementChild as HTMLElement;
+    const group: HTMLUListElement = row && row.nextElementSibling as HTMLUListElement;
+    const toggle: HTMLButtonElement = row
+      ? row.querySelector('.current-navigation-toggle') as HTMLButtonElement
+      : undefined;
+    entry.setAttribute('aria-expanded', expanded ? 'true' : 'false');
+    if (group && group.className.indexOf('current-navigation-group') >= 0) { group.hidden = !expanded; }
+    if (toggle) {
+      toggle.setAttribute('aria-expanded', expanded ? 'true' : 'false');
+      toggle.setAttribute('aria-label', (expanded ? this.strings.collapse : this.strings.expand) + ' ' + (label || ''));
+    }
+  }
+
+  private onKeydown = (event: KeyboardEvent): void => {
+    const target: HTMLElement = event.target as HTMLElement;
+    if (!target || target.className.indexOf('current-navigation-label') < 0) { return; }
+    const entry: HTMLLIElement = this.closestTreeItem(target);
+    if (!entry) { return; }
+    if (event.key === 'ArrowRight' && entry.hasAttribute('aria-expanded')) {
+      if (entry.getAttribute('aria-expanded') !== 'true') { this.setExpanded(entry, true, target.textContent); }
+      else { this.focusRelative(target, 1); }
+      event.preventDefault();
+    } else if (event.key === 'ArrowLeft') {
+      if (entry.getAttribute('aria-expanded') === 'true') { this.setExpanded(entry, false, target.textContent); }
+      else {
+        const parent: HTMLLIElement = this.parentTreeItem(entry);
+        if (parent) { (parent.querySelector('.current-navigation-label') as HTMLElement).focus(); }
+      }
+      event.preventDefault();
+    } else if (event.key === 'ArrowDown') {
+      this.focusRelative(target, 1); event.preventDefault();
+    } else if (event.key === 'ArrowUp') {
+      this.focusRelative(target, -1); event.preventDefault();
+    } else if (event.key === 'Home' || event.key === 'End') {
+      this.focusBoundary(event.key === 'Home'); event.preventDefault();
+    }
+  }
+
+  private visibleLabels(): HTMLElement[] {
+    if (!this.container) { return []; }
+    const labels: NodeListOf<Element> = this.container.querySelectorAll('.current-navigation-label');
+    const result: HTMLElement[] = [];
+    for (let i: number = 0; i < labels.length; i++) {
+      const label: HTMLElement = labels[i] as HTMLElement;
+      if (!this.hasHiddenParent(label)) { result.push(label); }
+    }
+    return result;
+  }
+  private focusRelative(current: HTMLElement, offset: number): void {
+    const labels: HTMLElement[] = this.visibleLabels();
+    const index: number = labels.indexOf(current);
+    if (index >= 0 && labels[index + offset]) { labels[index + offset].focus(); }
+  }
+  private focusBoundary(first: boolean): void {
+    const labels: HTMLElement[] = this.visibleLabels();
+    if (labels.length) { labels[first ? 0 : labels.length - 1].focus(); }
+  }
+  private hasHiddenParent(element: HTMLElement): boolean {
+    let current: HTMLElement = element.parentElement;
+    while (current && current !== this.container) {
+      if (current.hidden) { return true; }
+      current = current.parentElement;
+    }
+    return false;
+  }
+  private closestTreeItem(element: HTMLElement): HTMLLIElement {
+    let current: HTMLElement = element;
+    while (current && current !== this.container) {
+      if (current.getAttribute('role') === 'treeitem') { return current as HTMLLIElement; }
+      current = current.parentElement;
+    }
+    return undefined;
+  }
+  private parentTreeItem(entry: HTMLLIElement): HTMLLIElement {
+    let current: HTMLElement = entry.parentElement ? entry.parentElement.parentElement : undefined;
+    while (current && current !== this.container) {
+      if (current.getAttribute('role') === 'treeitem') { return current as HTMLLIElement; }
+      current = current.parentElement;
+    }
+    return undefined;
+  }
+  private containsCurrentItem(item: ICurrentNavigationItem): boolean {
+    if (item.url && this.isCurrentUrl(item.url)) { return true; }
+    for (let i: number = 0; i < item.items.length; i++) {
+      if (this.containsCurrentItem(item.items[i])) { return true; }
+    }
+    return false;
+  }
+  private isCurrentUrl(url: string): boolean {
+    return normalizeNavigationPath(window.location.href) === normalizeNavigationPath(url);
+  }
 }
diff --git a/src/extensions/currentNavigation/loc/de-de.js b/src/extensions/currentNavigation/loc/de-de.js
index c4828f8..9ed6015 100644
--- a/src/extensions/currentNavigation/loc/de-de.js
+++ b/src/extensions/currentNavigation/loc/de-de.js
@@ -3,6 +3,8 @@ define([], function() {
     "Title": "CurrentNavigationApplicationCustomizer",
     "NavigationLabel": "Navigation der aktuellen Website",
     "ConfigurationMissing": "Die aktuelle Navigation ist nicht konfiguriert.",
-    "LoadError": "Die aktuelle Navigation konnte nicht geladen werden."
+    "LoadError": "Die aktuelle Navigation konnte nicht geladen werden.",
+    "Expand": "Aufklappen",
+    "Collapse": "Zuklappen"
   };
 });
diff --git a/src/extensions/currentNavigation/loc/en-us.js b/src/extensions/currentNavigation/loc/en-us.js
index 9cacf5b..3563f53 100644
--- a/src/extensions/currentNavigation/loc/en-us.js
+++ b/src/extensions/currentNavigation/loc/en-us.js
@@ -3,6 +3,8 @@ define([], function() {
     "Title": "CurrentNavigationApplicationCustomizer",
     "NavigationLabel": "Current site navigation",
     "ConfigurationMissing": "Current navigation is not configured.",
-    "LoadError": "Current navigation could not be loaded."
+    "LoadError": "Current navigation could not be loaded.",
+    "Expand": "Expand",
+    "Collapse": "Collapse"
   };
 });
diff --git a/src/extensions/currentNavigation/loc/myStrings.d.ts b/src/extensions/currentNavigation/loc/myStrings.d.ts
index 2be89ce..23f0e3a 100644
--- a/src/extensions/currentNavigation/loc/myStrings.d.ts
+++ b/src/extensions/currentNavigation/loc/myStrings.d.ts
@@ -3,6 +3,8 @@ declare interface ICurrentNavigationApplicationCustomizerStrings {
   NavigationLabel: string;
   ConfigurationMissing: string;
   LoadError: string;
+  Expand: string;
+  Collapse: string;
 }
 
 declare module 'CurrentNavigationApplicationCustomizerStrings' {
diff --git a/tests/validate-static-assets.js b/tests/validate-static-assets.js
index 93e1b96..e331039 100644
--- a/tests/validate-static-assets.js
+++ b/tests/validate-static-assets.js
@@ -9,12 +9,20 @@ var manifest = json('src/extensions/currentNavigation/CurrentNavigationApplicati
 var app = read('src/extensions/currentNavigation/CurrentNavigationApplicationCustomizer.ts');
 var renderer = read('src/extensions/currentNavigation/CurrentNavigationRenderer.ts');
 var service = read('src/services/CurrentNavigationTaxonomyService.ts');
-assert('package version', packageJson.version === '1.0.0');
-assert('solution version', solution.version === '1.0.0.0');
+assert('package version', packageJson.version === '1.1.0');
+assert('solution version', solution.version === '1.1.0.0');
 assert('tenant deployment', solution.skipFeatureDeployment === true);
 assert('component type', manifest.extensionType === 'ApplicationCustomizer');
 assert('safe renderer', renderer.indexOf('innerHTML') < 0 && app.indexOf('innerHTML') < 0);
-assert('placeholder lifecycle cleanup', app.indexOf('changedEvent.remove') >= 0);
+assert('does not use Top placeholder', app.indexOf('PlaceholderName.Top') < 0);
+assert('targets modern SiteNavigation', app.indexOf('data-automationid="SiteNavigation"') >= 0);
+assert('restores native navigation', app.indexOf("classList.remove('current-navigation-managed')") >= 0);
+assert('native navigation is only replaced after successful load',
+  app.indexOf("classList.add('current-navigation-managed')") > app.indexOf('if (items.length'));
+assert('observer cleanup', app.indexOf('observer.disconnect()') >= 0);
+assert('treeview semantics', renderer.indexOf("setAttribute('role', root ? 'tree' : 'group')") >= 0 &&
+  renderer.indexOf("setAttribute('role', 'treeitem')") >= 0);
+assert('legacy selector compatibility', renderer.indexOf(':scope') < 0);
 assert('local properties loaded', service.indexOf('LocalCustomProperties') >= 0);
 assert('root property present', read('src/services/CurrentNavigationCore.ts').indexOf('CurrentNavigation.Root') >= 0);
 assert('hidden property present', read('src/services/CurrentNavigationCore.ts').indexOf('CurrentNavigation.Hidden') >= 0);