added screenshot cropping

app/static/index.html

@@ -118,7 +118,7 @@
               <div id="frames-info" class="mt-4 text-sm text-gray-500"></div>
             </div>
 
-            <div id="preview-pane" class="hidden flex flex-col items-center">
+            <div id="preview-pane" style="display: none;" class="flex-col items-center">
               <div id="preview-wrap" class="relative inline-block">
                 <img id="result-image" class="max-h-64 max-w-full rounded-lg block bg-gray-50" alt="" />
                 <svg id="result-overlay" class="absolute top-0 left-0 w-full h-full pointer-events-none" preserveAspectRatio="none"></svg>
@@ -331,7 +331,7 @@
         try { URL.revokeObjectURL(resultImg.src); } catch (_) {}
         resultImg.removeAttribute("src");
       }
-      $("preview-pane").classList.add("hidden");
+      $("preview-pane").style.display = "none";
     }
 
     function showError(msg) {
@@ -387,7 +387,7 @@
       const statusEl = $("preview-status");
 
       if (!state.result || state.result.media_type !== "image" || !state.file) {
-        pane.classList.add("hidden");
+        pane.style.display = "none";
         return;
       }
 
@@ -434,7 +434,7 @@
         label = T.preview_full;
       }
       statusEl.textContent = label;
-      pane.classList.remove("hidden");
+      pane.style.display = "flex";
     }
 
     function animateArc(fraction) {