diff --git a/layouts/_default/baseof.html b/layouts/_default/baseof.html
index 098548e..1204ae8 100644
--- a/layouts/_default/baseof.html
+++ b/layouts/_default/baseof.html
@@ -10,11 +10,11 @@
     {{ partial "footer.html" . }}
   </body>
   <script>
-      let bodyClasses = document.body.classList;
-      let systemDarkModeMatch = window.matchMedia('(prefers-color-scheme: dark)');
-      let localStorageDarkMode = localStorage.getItem('dark');
+      const bodyClasses = document.body.classList;
+      const systemDarkModeMatch = window.matchMedia('(prefers-color-scheme: dark)');
+      const localStorageDarkMode = localStorage.getItem('dark');
 
-      let setDark = (isDark) => {
+      const setDark = isDark => {
         bodyClasses[isDark ? 'add' : 'remove']('dark');
         localStorage.setItem('dark', isDark ? 'yes' : 'no');
       };