diff --git a/src/env.d.ts b/src/env.d.ts
index 5f05d461c5..5a4f540d5b 100644
--- a/src/env.d.ts
+++ b/src/env.d.ts
@@ -1,3 +1,4 @@
+/// <reference path="../.astro/types.d.ts" />
 /// <reference types="astro/client" />
 
 declare module "*.yml" {
diff --git a/src/layouts/Header/Navigation.astro b/src/layouts/Header/Navigation.astro
index d0a742ebec..a594d82bea 100644
--- a/src/layouts/Header/Navigation.astro
+++ b/src/layouts/Header/Navigation.astro
@@ -81,7 +81,7 @@ const data: Navigation[] = {
           & > ul {
             visibility: hidden;
             position: absolute;
-            z-index: 1;
+            z-index: 3;
             opacity: 0;
             width: 100%;
             min-width: 20vw;
diff --git a/src/layouts/Header/index.astro b/src/layouts/Header/index.astro
index 4348fc5227..cb6cf90de0 100644
--- a/src/layouts/Header/index.astro
+++ b/src/layouts/Header/index.astro
@@ -133,7 +133,7 @@ const theOtherLangUrl = canonicalUrl.pathname.startsWith("/en/")
       position: fixed;
       width: 100%;
       height: 100%;
-      z-index: 1;
+      z-index: 3;
       .hamburger-contents {
         display: block;
         flex: auto;
diff --git a/src/layouts/Toc.astro b/src/layouts/Toc.astro
index 16619988a4..40a6b234ae 100644
--- a/src/layouts/Toc.astro
+++ b/src/layouts/Toc.astro
@@ -198,7 +198,7 @@ for (const heading of Astro.props.headings) {
       position: sticky;
       top: 1rem;
       pointer-events: none;
-      z-index: 100;
+      z-index: 2;
     }
     #toc-toggle {
       display: flex;