use legacy build of pdf.js

static/pdf.js/viewer.css

@@ -1894,6 +1894,8 @@
     width:100%;
     height:100%;
     margin:0;
+    top:0;
+    left:0;
   }
 
 .annotationEditorLayer :is(.freeTextEditor, .inkEditor, .stampEditor) > .resizers{
@@ -2646,6 +2648,10 @@
 }
   }
 
+.pdfViewer.copyAll{
+    cursor:wait;
+  }
+
 .pdfViewer .canvasWrapper{
     overflow:hidden;
     width:100%;
@@ -2968,6 +2974,15 @@ body{
   scrollbar-color:var(--scrollbar-color) var(--scrollbar-bg-color);
 }
 
+body.wait::before{
+    content:"";
+    position:fixed;
+    width:100%;
+    height:100%;
+    z-index:100000;
+    cursor:wait;
+  }
+
 .hidden,
 [hidden]{
   display:none !important;