Book card interaction smooth 6

components/PublicGrid.tsx

@@ -539,9 +539,18 @@ function FlipBook({ pages, onClose }: { pages: string[]; onClose: () => void })
         aria-label="Chiudi"
       >✕</button>
 
+      {/* Container background shows through when on cover/back pages.
+          The page-flip canvas was patched (lib/page-flip/index.js) to clear
+          transparently instead of filling white, so this gradient is visible
+          on the empty half of the spread. */}
       <div
         ref={containerRef}
-        style={{ width: 'min(95vw, 1400px)', height: 'min(85vh, 900px)' }}
+        style={{
+          width: 'min(95vw, 1400px)',
+          height: 'min(85vh, 900px)',
+          background: 'linear-gradient(135deg, #4a3826 0%, #2e2114 55%, #1a1108 100%)',
+          boxShadow: 'inset 0 0 80px rgba(0,0,0,0.55)',
+        }}
         className="shadow-2xl"
       />