diff --git a/book.toml b/book.toml
index 3893bebc..f8646d52 100644
--- a/book.toml
+++ b/book.toml
@@ -8,11 +8,11 @@ language = "zh-CN"
 create-missing = false
 
 [output.epub]
-additional-css = ["src/indent.css"]
+additional-css = ["theme/indent.css"]
 cover-image = "illustrations/cover.jpg"
 no-section-label = true
 
 [output.typst-pdf]
 pdf = true
-custom-template = "src/template.typ"
+custom-template = "theme/template.typ"
 section-number = false
diff --git a/src/indent.css b/theme/indent.css
similarity index 100%
rename from src/indent.css
rename to theme/indent.css
diff --git a/src/template.typ b/theme/template.typ
similarity index 100%
rename from src/template.typ
rename to theme/template.typ