diff --git a/ARCHITECTURE.md b/ARCHITECTURE.md
index 37ad6e13..257b3ae8 100644
--- a/ARCHITECTURE.md
+++ b/ARCHITECTURE.md
@@ -2,7 +2,7 @@
 
 This is a short overview of the general architecture and structure of the repository, to help you orient yourself.
 
-This theme uses [sphinx-theme-builder](https://sphinx-theme-builder.readthedocs.io/en/latest/) as its build backend, and follows the [filesystem layout](https://sphinx-theme-builder.readthedocs.io/en/latest/reference/filesystem-layout/) recommended by it.
+This theme uses [sphinx-theme-builder](https://sphinx-theme-builder.readthedocs.io/en/latest/) as its build backend, and follows the [filesystem layout](https://sphinx-theme-builder.readthedocs.io/en/latest/filesystem-layout/) recommended by it.
 See below for some more specific sections
 
 ```{contents}
diff --git a/src/sphinx_book_theme/assets/scripts/index.js b/src/sphinx_book_theme/assets/scripts/index.js
index a5b2a594..d3238aee 100644
--- a/src/sphinx_book_theme/assets/scripts/index.js
+++ b/src/sphinx_book_theme/assets/scripts/index.js
@@ -131,7 +131,11 @@ var initTocHide = () => {
   };
 
   // Set up the intersection observer to watch all margin content
-  let tocObserver = new IntersectionObserver(hideTocCallback);
+  let options = {
+    // Trigger callback when the top of a margin item is 1/3 up the screen
+    rootMargin: "0px 0px -33% 0px",
+  };
+  let tocObserver = new IntersectionObserver(hideTocCallback, options);
   // TODO: deprecate popout after v0.5.0
   const selectorClasses = [
     "marginnote",