diff --git a/websites/fa2024/_includes/header_custom.html b/websites/fa2024/_includes/header_custom.html
new file mode 100644
index 0000000..2409171
--- /dev/null
+++ b/websites/fa2024/_includes/header_custom.html
@@ -0,0 +1,28 @@
+<button class="btn js-toggle-dark-mode fs-3">dark color scheme</button>
+
+<script>
+document.addEventListener('DOMContentLoaded', function() {
+  const toggleDarkMode = document.querySelector('.js-toggle-dark-mode');
+  const currentTheme = localStorage.getItem('theme') || 'light';
+
+  if (currentTheme === 'dark') {
+    jtd.setTheme('dark');
+    toggleDarkMode.textContent = 'light color scheme';
+  } else {
+    jtd.setTheme('light');
+    toggleDarkMode.textContent = 'dark color scheme';
+  }
+
+  jtd.addEvent(toggleDarkMode, 'click', function() {
+    if (jtd.getTheme() === 'dark') {
+      jtd.setTheme('light');
+      toggleDarkMode.textContent = 'dark color scheme';
+      localStorage.setItem('theme', 'light');
+    } else {
+      jtd.setTheme('dark');
+      toggleDarkMode.textContent = 'light color scheme';
+      localStorage.setItem('theme', 'dark');
+    }
+  });
+});
+</script>
diff --git a/websites/fa2024/_sass/custom/custom.scss b/websites/fa2024/_sass/custom/custom.scss
new file mode 100644
index 0000000..d933d94
--- /dev/null
+++ b/websites/fa2024/_sass/custom/custom.scss
@@ -0,0 +1,2 @@
+// per https://just-the-docs.com/docs/customization/#override-and-completely-custom-styles
+
diff --git a/websites/fa2024/index.md b/websites/fa2024/index.md
index fdcc498..dd69087 100644
--- a/websites/fa2024/index.md
+++ b/websites/fa2024/index.md
@@ -16,22 +16,6 @@ The Spark! Machine Learning Practicum gives you hands-on experience developing s
 for real world challenges.
 {: .fs-6 .fs-300}
 
-<button class="btn js-toggle-dark-mode">dark color scheme</button>
-
-<script>
-const toggleDarkMode = document.querySelector('.js-toggle-dark-mode');
-
-jtd.addEvent(toggleDarkMode, 'click', function(){
-  if (jtd.getTheme() === 'dark') {
-    jtd.setTheme('light');
-    toggleDarkMode.textContent = 'dark color scheme';
-  } else {
-    jtd.setTheme('dark');
-    toggleDarkMode.textContent = 'light color scheme';
-  }
-});
-</script>
-
 ---
 
 ## Logistics