diff --git a/index.html b/index.html
index 6a677e3..8e91477 100644
--- a/index.html
+++ b/index.html
@@ -64,6 +64,12 @@ body {
   line-height: 1em;
   color: lightgray;
 }
+#fg p.code {
+  font-family: monospace;
+  font-size: 0.4rem;
+  line-height: 1em;
+  color: gray;
+}
 #fg ul.icons {
   margin: 1rem 0;
   display: flex;
@@ -91,7 +97,8 @@ body {
       </div>
       <h1>Nf7</h1>
       <p class="subtitle">- visual programming platform -</p>
-      <p class="small">latest version: v0.4.0</p>
+      <p class="small">version: v0.4.1</p>
+      <p class="code">SHA1: A841FBA6E872328B7495AC2F34DF7F370E8E9B0F</p>
 
       <ul class="icons">
         <a href="https://github.com/falsycat/nf7" target="_blank" title="GitHub repo (mirror)">
@@ -102,7 +109,7 @@ body {
             </svg>
           </li>
         </a>
-        <a href="javascript:alert('in preparation...')" title="download">
+        <a href="https://anonymfile.com/n0EYL/nf7-v041raytracing.zip" target="_blank" title="download">
           <li>
             <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="currentColor" class="w-6 h-6">
               <path fill-rule="evenodd" d="M19.5 21a3 3 0 003-3V9a3 3 0 00-3-3h-5.379a.75.75 0 01-.53-.22L11.47 3.66A2.25 2.25 0 009.879 3H4.5a3 3 0 00-3 3v12a3 3 0 003 3h15zm-6.75-10.5a.75.75 0 00-1.5 0v4.19l-1.72-1.72a.75.75 0 00-1.06 1.06l3 3a.75.75 0 001.06 0l3-3a.75.75 0 10-1.06-1.06l-1.72 1.72V10.5z" clip-rule="evenodd" />