diff --git a/doc/book.toml b/doc/book.toml
index d8a6d84..249debf 100644
--- a/doc/book.toml
+++ b/doc/book.toml
@@ -8,6 +8,8 @@ language = "en"
 edition = "2021"
 
 [output.html]
+default-theme = "ayu"
+preferred-dark-theme = "ayu"
 mathjax-support = true
 site-url = "/garden/"
 git-repository-icon= "fa-gitlab"