frontend/src/lib/document/viewer/PdfViewer.svelte

@@ -170,13 +170,20 @@ function handleAnnotationClick(id: string) {
 		<p class="font-sans text-sm">Keine Datei vorhanden</p>
 	</div>
 {:else if renderer.error}
-	<div class="flex h-full w-full flex-col items-center justify-center gap-3 bg-pdf-bg text-ink-3">
-		<p class="font-sans text-sm text-red-400">{m.doc_render_failed()}</p>
+	<!-- role="alert" announces the failure to screen readers; the message text
+	     (not colour alone) carries the meaning. The download link is the only
+	     recovery action, so it is sized as a comfortable tap/focus target for
+	     the archive's older readers. -->
+	<div
+		role="alert"
+		class="flex h-full w-full flex-col items-center justify-center gap-3 bg-pdf-bg px-4 text-center text-ink-3"
+	>
+		<p class="font-sans text-base text-red-400">{m.doc_render_failed()}</p>
 		<a
 			href={url}
 			target="_blank"
 			rel="noopener noreferrer"
-			class="font-sans text-xs text-primary underline hover:text-ink-2"
+			class="inline-block py-2 font-sans text-sm text-primary underline hover:text-ink-2"
 		>
 			{m.doc_download_link()}
 		</a>

frontend/src/lib/document/viewer/PdfViewer.svelte.test.ts

@@ -44,6 +44,8 @@ describe('PdfViewer — render failure', () => {
 
 		await expect.element(page.getByText(m.doc_render_failed())).toBeVisible();
 		await expect.element(page.getByRole('link', { name: m.doc_download_link() })).toBeVisible();
+		// Announced to assistive tech, not a silent visual-only failure.
+		await expect.element(page.getByRole('alert')).toBeVisible();
 	});
 
 	it('does not show the failure message when the page renders successfully', async () => {