diff --git a/sites/preprocessor-docs/src/app.html b/sites/preprocessor-docs/src/app.html
index 079f42b..e435bdb 100644
--- a/sites/preprocessor-docs/src/app.html
+++ b/sites/preprocessor-docs/src/app.html
@@ -6,6 +6,8 @@
--topbar-top: var(--open-topbar-top);
--topbar-border: var(--hidden-topbar-border);
"
+ class="dark"
+ data-theme="amethyst"
>