diff --git a/public/demo/bim_0.html b/public/demo/bim_0.html
index ebdf10b..f4f505f 100644
--- a/public/demo/bim_0.html
+++ b/public/demo/bim_0.html
@@ -3,7 +3,7 @@
 <head>
     <link rel="icon" href="./demo/favicon.ico">
     <link rel="stylesheet" type="text/css" href="./demo/global.css">
-    <style>
+    <!-- <style>
         #myCanvas {
             position: absolute;
             width: calc(100% - 100px);
@@ -15,7 +15,7 @@
             left: 50px;
             top: 40px;
         }
-    </style>
+    </style> -->
 </head>
 
 <body>
diff --git a/public/demo/dxf_0.html b/public/demo/dxf_0.html
index 66c9c63..7e689ea 100644
--- a/public/demo/dxf_0.html
+++ b/public/demo/dxf_0.html
@@ -6,7 +6,7 @@
     <link rel="stylesheet" type="text/css" href="./demo/iconfont/iconfont.css">
     <link rel="stylesheet" href="./demo/layerManager/layerManager.css">
     <link rel="stylesheet" href="./demo/settings/SettingsPanel.css">
-    <style>
+    <!-- <style>
         #myCanvas {
             position: absolute;
             width: calc(100% - 100px);
@@ -18,7 +18,7 @@
             left: 50px;
             top: 40px;
         }
-    </style>
+    </style> -->
 </head>
 
 <body>
diff --git a/src/pages/examples/index.css b/src/pages/examples/index.css
index 8071ba7..8cab5e3 100644
--- a/src/pages/examples/index.css
+++ b/src/pages/examples/index.css
@@ -55,10 +55,10 @@
     background: lightblue;
 }
 
-.examples .content-container.open {
+/* .examples .content-container.open {
     opacity: 0.4;
     pointer-events: none;
-}
+} */
 
 .examples .content-container iframe {
     width: 100%;
@@ -66,7 +66,7 @@
     overflow: hidden;
 }
 
-.examples .content-overlay {
+/* .examples .content-overlay {
     position: absolute;
     z-index: 7;
     padding: 0;
@@ -81,7 +81,7 @@
 
 .examples .content-overlay.open {
     pointer-events: all;
-}
+} */
 
 .examples .page-title {
     position: absolute;
diff --git a/src/pages/examples/index.tsx b/src/pages/examples/index.tsx
index a606ec2..91033d0 100644
--- a/src/pages/examples/index.tsx
+++ b/src/pages/examples/index.tsx
@@ -27,9 +27,12 @@ function Examples() {
         iframeRef.current = document.createElement("iframe") as HTMLIFrameElement;
         preview.appendChild(iframeRef.current);
         if(code) {
-            iframeRef.current.contentWindow?.document.open();
-            iframeRef.current.contentWindow?.document.write(code);
-            iframeRef.current.contentWindow?.document.close();
+            const doc = iframeRef.current.contentWindow?.document;
+            if (doc) {
+                doc.open();
+                doc.write(code);
+                doc.close();
+            }
         }
     }
 
@@ -83,7 +86,7 @@ function Examples() {
                 {!collapsed ?  <MenuUnfoldOutlined /> : <MenuFoldOutlined />}
             </button>
             <div className={`page-title${collapsed? " open" : ""}`}>{title}</div>
-            <div className={`content-overlay${collapsed? " open" : ""}`} onClick={toggleCollapsed}></div>
+            {/* <div className={`content-overlay${collapsed? " open" : ""}`} onClick={toggleCollapsed}></div> */}
             <div className={`content-container${collapsed? " open" : ""}`} id="preview"></div>
             <div className={`menu${collapsed? " open" : ""}`}>
                 <div id="index">
