diff --git a/index.html b/index.html
index b49c04f..8c77653 100644
--- a/index.html
+++ b/index.html
@@ -8,6 +8,8 @@
   <link rel="mask-icon" href="/safari-pinned-tab.svg" color="#00aba9">
   <meta name="msapplication-TileColor" content="#00aba9">
   <meta name="theme-color" content="#ffffff">
+  <meta name="description" content="好的，今天我们来做菜！">
+  <title>隔离食用手册</title>
   <script>
     (function() {
       const prefersDark = window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches
@@ -18,6 +20,10 @@
   </script>
 </head>
 <body class="font-sans">
+  <!-- for img preview -->
+  <div style="display: none;">
+    <img src="/pwa-512x512.png" />
+  </div>
   <div id="app"></div>
   <script type="module" src="/src/main.ts"></script>
 </body>
diff --git a/public/pwa-192x192.png b/public/pwa-192x192.png
index 53add9c..26c8b77 100644
Binary files a/public/pwa-192x192.png and b/public/pwa-192x192.png differ
diff --git a/public/pwa-512x512.png b/public/pwa-512x512.png
index 6795997..505cfc6 100644
Binary files a/public/pwa-512x512.png and b/public/pwa-512x512.png differ
