diff --git a/docs/index.md b/docs/index.md
index c8a3fcb..543953d 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -8,13 +8,14 @@ nav_order: 1
 
 {: .no_toc }
 
-## Table of contents
-
-{: .no_toc .text-delta }
-
+<details open markdown="block">
+  <summary>
+    Table of contents
+  </summary>
+  {: .text-delta }
+- TOC
 {:toc}
-
----
+</details>
 
 ## Introduction