diff --git a/frontend/src/routes/art/+page.svelte b/frontend/src/routes/art/+page.svelte
index 81a1229..b0bd6c1 100644
--- a/frontend/src/routes/art/+page.svelte
+++ b/frontend/src/routes/art/+page.svelte
@@ -430,8 +430,12 @@
      vw the short edge — so it always fits. Desktop and portrait art never hit this. */
   @media (max-width: 640px) and (orientation: portrait) {
     .lightbox.rotate .lb-stage { transform: rotate(90deg); transform-origin: center; }
-    .lightbox.rotate .lb-frame { max-width: 90vh; }
-    .lightbox.rotate .lb-frame img { max-width: 82vh; max-height: 80vw; }
-    .lightbox.rotate .lb-frame.frame--none img { max-width: 92vh; max-height: 92vw; }
+    .lightbox.rotate .lb-cap { display: none; }   /* would sit sideways; the placard's on the page */
+    /* The image's SHORT edge + the frame's rail/mat map to the phone's narrow width, so
+       cap it there (max-height, pre-rotation) with a modest fixed frame so the whole
+       moulding always fits; the long edge (max-width → screen height) stays generous. */
+    .lightbox.rotate .lb-frame { max-width: 92vh; --rail: 16px; --mat: 16px; }
+    .lightbox.rotate .lb-frame img { max-width: 88vh; max-height: 74vw; }
+    .lightbox.rotate .lb-frame.frame--none img { max-width: 94vh; max-height: 92vw; }
   }
 </style>