diff --git a/frontend/src/components/Constructor/TransitionPreviewOverlay.tsx b/frontend/src/components/Constructor/TransitionPreviewOverlay.tsx
index 8d15278..bc7feff 100644
--- a/frontend/src/components/Constructor/TransitionPreviewOverlay.tsx
+++ b/frontend/src/components/Constructor/TransitionPreviewOverlay.tsx
@@ -36,14 +36,13 @@ const TransitionPreviewOverlay: React.FC<TransitionPreviewOverlayProps> = ({
 }) => {
   if (!isActive) return null;
 
-  // Video opacity: 0 while buffering, 1 otherwise
-  const videoOpacity = isBuffering ? 0 : 1;
-  // Container opacity: controlled by parent for fade-out effects
-  const containerOpacity = opacity ?? 1;
+  // Container opacity: 0 while buffering to prevent black flash
+  // Video first frame = old page background, so we hide everything until ready
+  const containerOpacity = isBuffering ? 0 : (opacity ?? 1);
 
   return (
     // Outer: full viewport with black background (letterbox bars)
-    // No fade transition - transition video itself is the effect
+    // Hidden while buffering to show old page content underneath
     <div
       className='fixed inset-0 z-50 overflow-hidden pointer-events-none bg-black'
       style={{ opacity: containerOpacity }}
@@ -53,14 +52,12 @@ const TransitionPreviewOverlay: React.FC<TransitionPreviewOverlayProps> = ({
         className='overflow-hidden'
         style={letterboxStyles || { position: 'absolute', inset: 0 }}
       >
-        {/* Video element - no opacity transition to ensure instant appearance
-            when ready. The video itself IS the transition effect. */}
+        {/* Video element - container handles visibility, video is always opaque */}
         <video
           ref={videoRef}
           className={`absolute inset-0 h-full w-full ${
             videoFit === 'cover' ? 'object-cover' : 'object-contain'
           }`}
-          style={{ opacity: videoOpacity }}
           muted
           playsInline
           preload='auto'