diff --git a/_quarto.yml b/_quarto.yml
index 4b543ab4..aaa11e4e 100644
--- a/_quarto.yml
+++ b/_quarto.yml
@@ -25,7 +25,9 @@ book:
 
   sidebar:
     search: true
-    collapse-level: 1	
+    collapse-level: 2
+    border: false
+    pinned: true
 
   page-navigation: true
   title: "MACHINE LEARNING SYSTEMS"