diff --git a/app/play/page.tsx b/app/play/page.tsx
index 346ec36..90a1856 100644
--- a/app/play/page.tsx
+++ b/app/play/page.tsx
@@ -30,10 +30,14 @@ import type {
 const MUTED_STORAGE_KEY = "infiplot:muted";
 
 // Cap how long we wait for the browser to download + decode a scene image
-// before giving up and rendering anyway. Runware's CDN is normally <2s for a
-// 1792×1024 PNG; tolerate up to 8s before the typewriter starts so a slow
-// download can't strand the player on a blank screen forever.
-const IMAGE_PRELOAD_TIMEOUT_MS = 8000;
+// before giving up and rendering anyway. Runware's CDN is usually <2s for a
+// 1792×1024 PNG, but over slow links / VPN / strict corp networks the same
+// download can stretch to 10-20s. The previous 8s ceiling fired in that
+// window, and because the rendered <img> has no aspect-ratio occupation, the
+// layout collapsed to a one-pixel-tall sliver until the bytes actually
+// finished arriving — "等了很久 → 一根线 → 突然出图" of the original report.
+// 20s + the <img> aspect-video fallback together remove that failure mode.
+const IMAGE_PRELOAD_TIMEOUT_MS = 20000;
 
 // ──────────────────────────────────────────────────────────────────────
 //  Image preload — decode the Runware URL in memory before committing to
diff --git a/components/PlayCanvas.tsx b/components/PlayCanvas.tsx
index 023ada6..9869ff1 100644
--- a/components/PlayCanvas.tsx
+++ b/components/PlayCanvas.tsx
@@ -310,11 +310,19 @@ export function PlayCanvas({
           className="relative inline-block"
           style={{ boxShadow: fullViewport ? "none" : SHADOW }}
         >
-          {/* Background image — Runware CDN URL or data URI (mock mode) */}
+          {/* Background image — Runware CDN URL or data URI (mock mode).
+              The width/height attributes are NOT rendered dimensions (w-auto
+              h-auto + the maxWidth/maxHeight in sizeStyle still drive the
+              final layout); they give the browser an intrinsic aspect ratio
+              so that, while the bytes are still arriving from the CDN, the
+              <img> reserves a 1792:1024 box instead of collapsing to a
+              one-pixel sliver — fixes the "等很久 → 一根线 → 突然出图" jank. */}
           <img
             key={imageUrl.slice(-48)}
             ref={imgRef}
             src={imageUrl}
+            width={1792}
+            height={1024}
             alt="Generated scene"
             onClick={handleImageClick}
             draggable={false}