diff --git a/slides/images/cover.jpg b/slides/images/cover.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..59a5db4c02e8022a041c4d7002e273b34d2cd360
Binary files /dev/null and b/slides/images/cover.jpg differ
diff --git a/slides/slides.md b/slides/slides.md
index 2f2d33f4ace64d5d0b1b519440b7efd1842b5842..63dd7f7bdfa5d25a2a67d889ebf9bc6da94332a0 100644
--- a/slides/slides.md
+++ b/slides/slides.md
@@ -14,6 +14,7 @@ drawings:
 transition: fade-out
 # use UnoCSS
 css: unocss
+background: /images/cover.jpg
 ---
 
 # ALP4 Tutorial 10
@@ -27,8 +28,6 @@ css: unocss
   </a>
 </div>
 
-<!---->
-
 ---
 transition: slide-left
 src: ./pages/recap.md