diff --git a/apps/web/src/app/(portal)/marketplace/components/MarketplaceCard.test.tsx b/apps/web/src/app/(portal)/marketplace/components/MarketplaceCard.test.tsx
index 8483cf3..a43e902 100644
--- a/apps/web/src/app/(portal)/marketplace/components/MarketplaceCard.test.tsx
+++ b/apps/web/src/app/(portal)/marketplace/components/MarketplaceCard.test.tsx
@@ -4,15 +4,21 @@ import { afterEach, describe, expect, it, vi } from 'vitest';
 
 // Mock next-intl useTranslations
 vi.mock('next-intl', () => ({
-  useTranslations: () => (key: string) => {
+  useTranslations: () => (key: string, values?: Record<string, string | number>) => {
     const translations: Record<string, string> = {
       activate: 'Modul aktivieren',
       deactivate: 'Deaktivieren',
       statusActive: 'Aktiviert',
       statusAvailable: 'Verfuegbar',
       statusNoAccess: 'Kein Zugriff',
+      openDetail: 'Details zu {name} öffnen',
     };
-    return translations[key] ?? key;
+    const template = translations[key] ?? key;
+    if (!values) return template;
+    return Object.entries(values).reduce(
+      (acc, [placeholder, value]) => acc.replace(`{${placeholder}}`, String(value)),
+      template,
+    );
   },
 }));
 
@@ -81,7 +87,15 @@ describe('MarketplaceCard', () => {
     expect(onToggle).toHaveBeenCalledWith('mod-1', false);
   });
 
-  it('shows the "Kein Zugriff" badge for an active module without access and clicking the card triggers the toast instead of navigating (D-08)', async () => {
+  it('does not render a card overlay button for a not-yet-activated module (D-01)', () => {
+    render(<MarketplaceCard {...baseProps} isActive={false} />);
+
+    expect(
+      screen.queryByRole('button', { name: 'Details zu Domaincheck öffnen' }),
+    ).not.toBeInTheDocument();
+  });
+
+  it('shows the "Kein Zugriff" badge for an active module without access and mouse-clicking the overlay button triggers the toast instead of navigating (D-08)', async () => {
     const onOpenDetail = vi.fn();
     const onLockedClick = vi.fn();
     const user = userEvent.setup();
@@ -98,13 +112,13 @@ describe('MarketplaceCard', () => {
 
     expect(screen.getByText('Kein Zugriff')).toBeInTheDocument();
 
-    await user.click(screen.getByText('Domaincheck'));
+    await user.click(screen.getByRole('button', { name: 'Details zu Domaincheck öffnen' }));
 
     expect(onLockedClick).toHaveBeenCalledOnce();
     expect(onOpenDetail).not.toHaveBeenCalled();
   });
 
-  it('does not show the "Kein Zugriff" badge for an active module with access and clicking the card navigates', async () => {
+  it('does not show the "Kein Zugriff" badge for an active module with access and mouse-clicking the overlay button navigates', async () => {
     const onOpenDetail = vi.fn();
     const onLockedClick = vi.fn();
     const user = userEvent.setup();
@@ -121,14 +135,80 @@ describe('MarketplaceCard', () => {
 
     expect(screen.queryByText('Kein Zugriff')).not.toBeInTheDocument();
 
-    await user.click(screen.getByText('Domaincheck'));
+    await user.click(screen.getByRole('button', { name: 'Details zu Domaincheck öffnen' }));
 
     expect(onOpenDetail).toHaveBeenCalledOnce();
     expect(onOpenDetail).toHaveBeenCalledWith('domaincheck');
     expect(onLockedClick).not.toHaveBeenCalled();
   });
 
-  it('leaves the not-activated state unchanged: no access badge, and clicking the card does not fire navigate or locked callbacks', async () => {
+  it('opens the module detail via a real keyboard activation of the focused overlay button (D-01)', async () => {
+    const onOpenDetail = vi.fn();
+    const user = userEvent.setup();
+
+    render(
+      <MarketplaceCard
+        {...baseProps}
+        isActive={true}
+        hasAccess={true}
+        onOpenDetail={onOpenDetail}
+      />,
+    );
+
+    const overlay = screen.getByRole('button', { name: 'Details zu Domaincheck öffnen' });
+    overlay.focus();
+    await user.keyboard('{Enter}');
+
+    expect(onOpenDetail).toHaveBeenCalledOnce();
+    expect(onOpenDetail).toHaveBeenCalledWith('domaincheck');
+  });
+
+  it('triggers the locked hint via a real keyboard activation of the focused overlay button (D-01, D-08)', async () => {
+    const onLockedClick = vi.fn();
+    const onOpenDetail = vi.fn();
+    const user = userEvent.setup();
+
+    render(
+      <MarketplaceCard
+        {...baseProps}
+        isActive={true}
+        hasAccess={false}
+        onLockedClick={onLockedClick}
+        onOpenDetail={onOpenDetail}
+      />,
+    );
+
+    const overlay = screen.getByRole('button', { name: 'Details zu Domaincheck öffnen' });
+    overlay.focus();
+    await user.keyboard('{Enter}');
+
+    expect(onLockedClick).toHaveBeenCalledOnce();
+    expect(onOpenDetail).not.toHaveBeenCalled();
+  });
+
+  it('keeps the activate/deactivate footer button as its own reachable tab stop that does not additionally open the detail overlay', async () => {
+    const onToggle = vi.fn();
+    const onOpenDetail = vi.fn();
+    const user = userEvent.setup();
+
+    render(
+      <MarketplaceCard
+        {...baseProps}
+        isActive={true}
+        hasAccess={true}
+        onToggle={onToggle}
+        onOpenDetail={onOpenDetail}
+      />,
+    );
+
+    await user.click(screen.getByRole('button', { name: 'Deaktivieren' }));
+
+    expect(onToggle).toHaveBeenCalledOnce();
+    expect(onToggle).toHaveBeenCalledWith('mod-1', true);
+    expect(onOpenDetail).not.toHaveBeenCalled();
+  });
+
+  it('leaves the not-activated state unchanged: no access badge, no overlay button, and clicking the visible text does not fire navigate or locked callbacks', async () => {
     const onOpenDetail = vi.fn();
     const onLockedClick = vi.fn();
     const user = userEvent.setup();
diff --git a/apps/web/src/app/(portal)/marketplace/components/MarketplaceCard.tsx b/apps/web/src/app/(portal)/marketplace/components/MarketplaceCard.tsx
index 37523a4..008bd68 100644
--- a/apps/web/src/app/(portal)/marketplace/components/MarketplaceCard.tsx
+++ b/apps/web/src/app/(portal)/marketplace/components/MarketplaceCard.tsx
@@ -114,16 +114,22 @@ export function MarketplaceCard({
 
   return (
     <div
-      className={`rounded-lg border border-border bg-card p-5 shadow-sm transition-all ${
-        locked
-          ? 'opacity-60 cursor-not-allowed'
-          : isActive
-            ? 'hover:shadow-md hover:border-primary/30 cursor-pointer'
-            : 'hover:shadow-md hover:border-primary/30'
+      className={`relative rounded-lg border border-border bg-card p-5 shadow-sm transition-all ${
+        locked ? 'opacity-60' : 'hover:shadow-md hover:border-primary/30'
       }`}
       style={{ minHeight: '180px' }}
-      onClick={isActive ? handleCardClick : undefined}
     >
+      {/* Deckende Schaltflaeche: traegt den Kartenklick, damit die verschachtelte
+          Aktivieren-Schaltflaeche im Fuss kein <button> in einem <button> wird. */}
+      {isActive && (
+        <button
+          type="button"
+          onClick={handleCardClick}
+          aria-label={t('openDetail', { name })}
+          className={`absolute inset-0 rounded-lg ${locked ? 'cursor-not-allowed' : 'cursor-pointer'}`}
+        />
+      )}
+
       {/* Header: icon + name + badges */}
       <div className="flex items-start gap-3 mb-3">
         <div className="rounded-md bg-muted p-2.5 shrink-0">
@@ -167,7 +173,7 @@ export function MarketplaceCard({
 
       {/* Footer: action button — only rendered for users who may activate/deactivate */}
       {canManage && (
-        <div className="flex items-center justify-end">
+        <div className="relative flex items-center justify-end">
           <button
             type="button"
             onClick={(e) => {
diff --git a/apps/web/src/messages/de.json b/apps/web/src/messages/de.json
index 590a735..81e346d 100644
--- a/apps/web/src/messages/de.json
+++ b/apps/web/src/messages/de.json
@@ -747,7 +747,8 @@
     "accessDenied": "Zugriff verweigert",
     "statusNoAccess": "Kein Zugriff",
     "toastNoAccess": "Kein Zugriff auf dieses Modul — wenden Sie sich an Ihren Administrator.",
-    "notFound": "Dieses Modul wurde nicht gefunden."
+    "notFound": "Dieses Modul wurde nicht gefunden.",
+    "openDetail": "Details zu {name} öffnen"
   },
   "certManager": {
     "title": "Zertifikat-Manager",
diff --git a/apps/web/src/messages/en.json b/apps/web/src/messages/en.json
index ca7884b..9221ad9 100644
--- a/apps/web/src/messages/en.json
+++ b/apps/web/src/messages/en.json
@@ -747,7 +747,8 @@
     "accessDenied": "Access denied",
     "statusNoAccess": "No Access",
     "toastNoAccess": "No access to this module — please contact your administrator.",
-    "notFound": "This module was not found."
+    "notFound": "This module was not found.",
+    "openDetail": "Open details for {name}"
   },
   "certManager": {
     "title": "Certificate Manager",