diff --git a/theme/classic.html b/theme/classic.html
index 9475168..8b0db71 100644
--- a/theme/classic.html
+++ b/theme/classic.html
@@ -489,7 +489,7 @@
 <!--GuestUploadStart--><script type="text/javascript" src="//cdn.bootcss.com/spark-md5/3.0.0/spark-md5.min.js"></script><!--GuestUploadEnd-->
 <!--AliyundriveUploadJsStart--><script src="https://unpkg.com/bignumber.js@9.0.2/bignumber.js"></script>
 <script src="https://www.unpkg.com/js-sha1@0.6.0/src/sha1.js"></script><!--AliyundriveUploadJsEnd-->
-<!--IsFileStart--><!--IspdfFileStart--><script src="//cdn.bootcss.com/pdf.js/2.3.200/pdf.min.js"></script><!--IspdfFileEnd--><!--IsFileEnd-->
+<!--IsFileStart--><!--IspdfFileStart--><script src="https://unpkg.com/pdfjs-dist@2.13.216/build/pdf.min.js"></script><!--IspdfFileEnd--><!--IsFileEnd-->
 <!--ListEnd-->
 <script type="text/javascript">
     function changelanguage(str)
@@ -655,26 +655,63 @@
     addVideos(["<!--FileEncodeUrl-->"]);
 <!--IsvideoFileEnd-->
 <!--IspdfFileStart-->
-    pdfjsLib.GlobalWorkerOptions.workerSrc = '//cdn.bootcss.com/pdf.js/2.3.200/pdf.worker.min.js';
+    //cdn.bootcss.com/pdf.js/2.3.200/pdf.worker.min.js
+    pdfjsLib.GlobalWorkerOptions.workerSrc = 'https://unpkg.com/pdfjs-dist@2.13.216/build/pdf.worker.min.js';
     var loadingTask = pdfjsLib.getDocument({
         url: "<!--FileDownUrl-->",
-        cMapUrl: "//cdn.jsdelivr.net/npm/pdfjs-dist@2.2.228/cmaps/",
+        cMapUrl: "https://unpkg.com/pdfjs-dist@2.13.216/cmaps/",
         cMapPacked: true,
-        rangeChunkSize: 65535
+        disableStream: true,
+        disableAutoFetch: true,
+        rangeChunkSize: 65535*16
     });
     loadingTask.promise.then(function(pdf) {
         var pagenum =  pdf.numPages;
         var pdfContainer = document.getElementById('pdf-d');
         pdfContainer.innerHTML = '';
-        for (var i=1;i<=pagenum;i++) {
-            var canvasNew = document.createElement('canvas');
-            canvasNew.id = 'pdf-c'+i;
-            pdfContainer.appendChild(canvasNew);
-            renderpage(pdf,i);
+        if (pagenum>5) {
+            var pagepos = 0;
+            for (var i=1;i<=5;i++) {
+                var canvasNew = document.createElement('canvas');
+                canvasNew.id = 'pdf-c'+i;
+                pdfContainer.appendChild(canvasNew);
+                renderpage(pdf,i);
+            }
+            pagepos = i;
+            var pdfnextpagebutton = document.createElement('button');
+            pdfnextpagebutton.id = 'pdfnextpagebutton';
+            pdfnextpagebutton.innerText = 'Load page ' + pagepos + '-' + (pagepos+4<pagenum?pagepos+4:pagenum) + ' (' + pagenum + ')';
+            pdfnextpagebutton.setAttribute('onclick', "this.style.display = 'none';");
+            pdfContainer.appendChild(pdfnextpagebutton);
+            var pdfWaitNextPage = setInterval(function(){
+                //console.log(document.documentElement.scrollTop + ", " + document.body.scrollHeight);
+                if (pdfnextpagebutton.style.display=='none') {
+                    for (var i=pagepos;i<(pagepos+5<pagenum?pagepos+5:pagenum);i++) {
+                        var canvasNew = document.createElement('canvas');
+                        canvasNew.id = 'pdf-c'+i;
+                        pdfContainer.appendChild(canvasNew);
+                        renderpage(pdf,i);
+                    }
+                    pagepos = i;
+                    if (pagepos<pagenum) {
+                        pdfnextpagebutton.innerText = 'Load page ' + pagepos + '-' + (pagepos+5<pagenum?pagepos+5:pagenum) + ' (' + pagenum + ')';
+                        pdfnextpagebutton.style.display ='';
+                        pdfContainer.appendChild(pdfnextpagebutton);
+                    } else {
+                        clearInterval(pdfWaitNextPage);
+                    }
+                }
+            }, 1000);
+        } else {
+            for (var i=1;i<=pagenum;i++) {
+                var canvasNew = document.createElement('canvas');
+                canvasNew.id = 'pdf-c'+i;
+                pdfContainer.appendChild(canvasNew);
+                renderpage(pdf,i);
+            }
         }
     });
-    function renderpage(pdf,i)
-    {
+    function renderpage(pdf,i) {
         pdf.getPage(i).then(function(page) { 
             var scale = 1.5;
             var viewport = page.getViewport({ scale: scale, });