优先加载CDN，失败后fallback为本地js

src/index.html

@@ -63,11 +63,38 @@
         </div> -->
     </div>
 
+    <script>
+        // CDN 资源加载失败时 fallback （使用本地js）
+        // refer: https://blog.csdn.net/weixin_44326389/article/details/104041963
+
+        function errorload(elem) { //cdn错误
+            if (elem.getAttribute('data-errorTimes') == 1) {
+                elem.onerror = null; // 执行完 onerror 事件后，置 οnerrοr = null 来清除 onerror 事件。
+                return;
+            }
+            elem.setAttribute('data-errorTimes', 1);
+            var _src = elem.getAttribute('local-src');
+            loadScript(_src, elem);
+        }
+
+        function loadScript(_src, prevEl) { //引入本地js
+            var _el = document.createElement('script');
+            _el.src = _src;
+            if (prevEl) {
+                prevEl.parentNode.insertBefore(_el, prevEl.nextSibling);
+            } else {
+                document.body.appendChild(_el);
+            }
+        }
+    </script>
+
     <!-- D3.js refer: https://d3js.org/ -->
-    <script src="./assets/lib/d3/7.4.4/d3.min.js"></script>
+    <script src="https://cdn.staticfile.org/d3/7.4.4/d3.min.js" local-src="./assets/lib/d3/7.4.4/d3.min.js"
+        onerror="errorload(this);"></script>
 
     <!-- GSAP refer: https://greensock.com/docs/v3/Installation -->
-    <script src="./assets/lib/gsap/3.10.4/gsap.min.js"></script>
+    <script src="https://cdn.staticfile.org/gsap/3.10.4/gsap.min.js" local-src="./assets/lib/gsap/3.10.4/gsap.min.js"
+        onerror="errorload(this);"></script>
 
     <!-- class -->
     <script src="./assets/js/class.js"></script>