diff --git a/frontend/src/lib/document/viewer/PdfViewer.svelte.test.ts b/frontend/src/lib/document/viewer/PdfViewer.svelte.test.ts
index 583e1f91..12383c6d 100644
--- a/frontend/src/lib/document/viewer/PdfViewer.svelte.test.ts
+++ b/frontend/src/lib/document/viewer/PdfViewer.svelte.test.ts
@@ -40,107 +40,139 @@ describe('PdfViewer — empty / error states', () => {
 		render(PdfViewer, { url: '' });
 
 		const buttons = document.querySelectorAll('button');
-		// Empty state has no nav buttons
 		expect(buttons.length).toBe(0);
 	});
 });
 
 describe('PdfViewer — loaded state', () => {
-	it('renders annotation toggle controls', async () => {
+	it('renders the PDF navigation controls (Zurück/Weiter/Vergrößern/Verkleinern) when a url is provided', async () => {
 		render(PdfViewer, {
 			url: '/api/documents/test/file',
 			documentId: 'test',
 			annotationReloadKey: 0
 		});
 
-		// The PdfControls component renders the toggle button
-		await new Promise((r) => setTimeout(r, 50));
-		const buttons = document.querySelectorAll('button');
-		expect(buttons.length).toBeGreaterThan(0);
+		// PdfControls renders its nav + zoom buttons once the document.promise resolves.
+		await expect.element(page.getByRole('button', { name: 'Zurück' })).toBeVisible();
+		await expect.element(page.getByRole('button', { name: 'Weiter' })).toBeVisible();
+		await expect.element(page.getByRole('button', { name: 'Vergrößern' })).toBeVisible();
+		await expect.element(page.getByRole('button', { name: 'Verkleinern' })).toBeVisible();
 	});
 
-	it('passes annotationsDimmed=true to the AnnotationLayer wrapper', async () => {
+	it('renders the canvas background container when annotationsDimmed=true', async () => {
 		render(PdfViewer, {
 			url: '/api/documents/test/file',
 			documentId: 'test',
 			annotationsDimmed: true
 		});
 
-		await new Promise((r) => setTimeout(r, 50));
-		// just confirm no throw in the dimmed code path
-		expect(document.querySelector('.bg-pdf-bg')).not.toBeNull();
+		await vi.waitFor(() => {
+			expect(document.querySelector('.bg-pdf-bg')).not.toBeNull();
+		});
 	});
 
-	it('renders without throwing in transcribeMode', async () => {
-		expect(() =>
-			render(PdfViewer, {
-				url: '/api/documents/test/file',
-				documentId: 'test',
-				transcribeMode: true
-			})
-		).not.toThrow();
-	});
-
-	it('renders without throwing with a documentFileHash and matching annotations', async () => {
-		expect(() =>
-			render(PdfViewer, {
-				url: '/api/documents/test/file',
-				documentId: 'test',
-				documentFileHash: 'abc123'
-			})
-		).not.toThrow();
-	});
-
-	it('renders without throwing with a flashAnnotationId set', async () => {
-		expect(() =>
-			render(PdfViewer, {
-				url: '/api/documents/test/file',
-				documentId: 'test',
-				flashAnnotationId: 'ann-flashing'
-			})
-		).not.toThrow();
-	});
-
-	it('renders without throwing with blockNumbers set', async () => {
-		expect(() =>
-			render(PdfViewer, {
-				url: '/api/documents/test/file',
-				documentId: 'test',
-				blockNumbers: { 'ann-1': 1, 'ann-2': 2 }
-			})
-		).not.toThrow();
-	});
-
-	it('renders without throwing with an activeAnnotationId set', async () => {
-		expect(() =>
-			render(PdfViewer, {
-				url: '/api/documents/test/file',
-				documentId: 'test',
-				activeAnnotationId: 'ann-1'
-			})
-		).not.toThrow();
-	});
-
-	it('renders without throwing in transcribeMode + canvas + activeAnnotationId combo', async () => {
-		expect(() =>
+	it('forces the annotation toggle into "hide" mode when transcribeMode is true and annotations exist', async () => {
+		const fetchSpy = vi.spyOn(globalThis, 'fetch').mockResolvedValue(
+			new Response(
+				JSON.stringify([
+					{
+						id: 'a1',
+						documentId: 'test',
+						pageNumber: 1,
+						x: 0.1,
+						y: 0.1,
+						width: 0.1,
+						height: 0.1,
+						color: '#000',
+						createdAt: '2026-01-01T00:00:00Z',
+						fileHash: 'match'
+					}
+				]),
+				{ status: 200, headers: { 'Content-Type': 'application/json' } }
+			)
+		);
+		try {
 			render(PdfViewer, {
 				url: '/api/documents/test/file',
 				documentId: 'test',
 				transcribeMode: true,
-				activeAnnotationId: 'ann-1'
-			})
-		).not.toThrow();
+				documentFileHash: 'match'
+			});
+
+			// transcribeMode forces showAnnotations=true; toggle button surfaces with "hide" label
+			// (only when annotationCount > 0).
+			await expect
+				.element(page.getByRole('button', { name: /annotierungen verbergen/i }))
+				.toBeVisible();
+		} finally {
+			fetchSpy.mockRestore();
+		}
 	});
 
-	it('survives onAnnotationClick callback being invoked indirectly', async () => {
+	it('renders the canvas region when documentFileHash is provided', async () => {
+		render(PdfViewer, {
+			url: '/api/documents/test/file',
+			documentId: 'test',
+			documentFileHash: 'abc123'
+		});
+
+		await vi.waitFor(() => {
+			expect(document.querySelector('.bg-pdf-bg')).not.toBeNull();
+		});
+	});
+
+	it('renders the PDF controls when flashAnnotationId is set', async () => {
+		render(PdfViewer, {
+			url: '/api/documents/test/file',
+			documentId: 'test',
+			flashAnnotationId: 'ann-flashing'
+		});
+
+		await expect.element(page.getByRole('button', { name: 'Zurück' })).toBeVisible();
+	});
+
+	it('renders the PDF controls when blockNumbers map is provided', async () => {
+		render(PdfViewer, {
+			url: '/api/documents/test/file',
+			documentId: 'test',
+			blockNumbers: { 'ann-1': 1, 'ann-2': 2 }
+		});
+
+		await expect.element(page.getByRole('button', { name: 'Zurück' })).toBeVisible();
+	});
+
+	it('renders the PDF controls when activeAnnotationId is set', async () => {
+		render(PdfViewer, {
+			url: '/api/documents/test/file',
+			documentId: 'test',
+			activeAnnotationId: 'ann-1'
+		});
+
+		await expect.element(page.getByRole('button', { name: 'Zurück' })).toBeVisible();
+	});
+
+	it('renders the PDF nav controls in transcribeMode + activeAnnotationId combo', async () => {
+		render(PdfViewer, {
+			url: '/api/documents/test/file',
+			documentId: 'test',
+			transcribeMode: true,
+			activeAnnotationId: 'ann-1'
+		});
+
+		// Without an annotations fetch, the visibility toggle is hidden — just assert the always-on nav.
+		await expect.element(page.getByRole('button', { name: 'Zurück' })).toBeVisible();
+		await expect.element(page.getByRole('button', { name: 'Weiter' })).toBeVisible();
+	});
+
+	it('renders the PDF controls when an onAnnotationClick callback is wired up', async () => {
 		const onAnnotationClick = vi.fn();
-		expect(() =>
-			render(PdfViewer, {
-				url: '/api/documents/test/file',
-				documentId: 'test',
-				onAnnotationClick
-			})
-		).not.toThrow();
+		render(PdfViewer, {
+			url: '/api/documents/test/file',
+			documentId: 'test',
+			onAnnotationClick
+		});
+
+		await expect.element(page.getByRole('button', { name: 'Zurück' })).toBeVisible();
 	});
 
 	it('shows the outdated-annotation notice when annotations have non-matching fileHash', async () => {
@@ -170,9 +202,9 @@ describe('PdfViewer — loaded state', () => {
 				documentFileHash: 'new-hash'
 			});
 
-			await new Promise((r) => setTimeout(r, 100));
-			const notice = document.querySelector('[data-testid="annotation-outdated-notice"]');
-			expect(notice).not.toBeNull();
+			await vi.waitFor(() => {
+				expect(document.querySelector('[data-testid="annotation-outdated-notice"]')).not.toBeNull();
+			});
 		} finally {
 			fetchSpy.mockRestore();
 		}
@@ -205,41 +237,42 @@ describe('PdfViewer — loaded state', () => {
 				documentFileHash: 'matching-hash'
 			});
 
-			await new Promise((r) => setTimeout(r, 100));
-			const notice = document.querySelector('[data-testid="annotation-outdated-notice"]');
-			expect(notice).toBeNull();
+			// Controls finish mounting, and the outdated notice stays absent.
+			await expect.element(page.getByRole('button', { name: 'Zurück' })).toBeVisible();
+			expect(document.querySelector('[data-testid="annotation-outdated-notice"]')).toBeNull();
 		} finally {
 			fetchSpy.mockRestore();
 		}
 	});
 
-	it('handles fetch error when loading annotations gracefully', async () => {
+	it('still renders the controls when the annotations fetch rejects', async () => {
 		const fetchSpy = vi.spyOn(globalThis, 'fetch').mockRejectedValue(new Error('network'));
 		try {
-			expect(() =>
-				render(PdfViewer, {
-					url: '/api/documents/test/file',
-					documentId: 'test'
-				})
-			).not.toThrow();
-			await new Promise((r) => setTimeout(r, 50));
+			render(PdfViewer, {
+				url: '/api/documents/test/file',
+				documentId: 'test'
+			});
+
+			// PDF rendering does not depend on the annotations fetch — controls still appear.
+			await expect.element(page.getByRole('button', { name: 'Zurück' })).toBeVisible();
+			expect(document.querySelector('[data-testid="annotation-outdated-notice"]')).toBeNull();
 		} finally {
 			fetchSpy.mockRestore();
 		}
 	});
 
-	it('handles non-OK fetch response when loading annotations', async () => {
+	it('still renders the controls when the annotations fetch returns a non-OK status', async () => {
 		const fetchSpy = vi
 			.spyOn(globalThis, 'fetch')
 			.mockResolvedValue(new Response('error', { status: 500 }));
 		try {
-			expect(() =>
-				render(PdfViewer, {
-					url: '/api/documents/test/file',
-					documentId: 'test'
-				})
-			).not.toThrow();
-			await new Promise((r) => setTimeout(r, 50));
+			render(PdfViewer, {
+				url: '/api/documents/test/file',
+				documentId: 'test'
+			});
+
+			await expect.element(page.getByRole('button', { name: 'Zurück' })).toBeVisible();
+			expect(document.querySelector('[data-testid="annotation-outdated-notice"]')).toBeNull();
 		} finally {
 			fetchSpy.mockRestore();
 		}