Fix base URL for external sharing Change-Id: Ie4571304975d12a5914e00d28c185757677af879

diff --git a/packages/frontend/web/index.html b/packages/frontend/web/index.html
index 7c6d468..fa0ed11 100644
--- a/packages/frontend/web/index.html
+++ b/packages/frontend/web/index.html

@@ -8,8 +8,9 @@
 
     <script>
         var pathname = window.location.pathname;
-        var match = pathname.match(/^\/hosting\/[^\/]+\//);
+        var match = pathname.match(/^\/(?:hosting|asset)\/[^\/]+(?:\/zpc\/[^\/]+)?/);
         var baseHref = match ? match[0] : '/';
+        if (!baseHref.endsWith('/')) baseHref += '/';
         document.write('<base href="' + baseHref + '">');
     </script>
 
@@ -29,4 +30,4 @@
 <body>
 </body>
 
-</html>
\ No newline at end of file
+</html>