diff --git a/quarto/templates/slides/index00.qmd b/quarto/templates/slides/index00.qmd
index dab1229..8230acb 100644
--- a/quarto/templates/slides/index00.qmd
+++ b/quarto/templates/slides/index00.qmd
@@ -18,6 +18,8 @@ format:
     callot-style: simple
     css: [css/default.css, css/callouts.css]
     footer: <https://quarto.org>
+    mermaid:
+      theme: dark
   gfm:
     author: Miguel Xochicale
 ---