fix: Center confirmation modal using transform

- Use fixed positioning with top/left 50% and translate -50%
- More reliable centering regardless of parent containers
- Add max-width for mobile responsiveness

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

web/components/ScraperTest.tsx

@@ -1273,12 +1273,12 @@ export default function ScraperTest({ onJobsChange, onSelectReviews }: ScraperTe
       {/* Confirmation Modal */}
       {showConfirmModal && (
         <div
-          className="fixed inset-0 z-50 flex items-center justify-center bg-black/50 backdrop-blur-sm p-4"
+          className="fixed inset-0 z-50 bg-black/50 backdrop-blur-sm"
           onClick={() => setShowConfirmModal(false)}
         >
           <div
-            className="bg-white rounded-2xl shadow-2xl max-w-md border-2 border-green-500 animate-fade-in"
+            className="fixed top-1/2 left-1/2 -translate-x-1/2 -translate-y-1/2 bg-white rounded-2xl shadow-2xl border-2 border-green-500 animate-fade-in"
-            style={{ width: '400px' }}
+            style={{ width: '400px', maxWidth: 'calc(100vw - 32px)' }}
             onClick={(e) => e.stopPropagation()}
           >
             {/* Header */}