diff --git a/static/css/cours.css b/static/css/cours.css
index eeb4729..9871b74 100644
--- a/static/css/cours.css
+++ b/static/css/cours.css
@@ -3,6 +3,11 @@
 :root {
   --max-width: 900px;
   --sidebar-width: 20%;
+  --shift-icon-filetree: -10px;
+
+  /* Size of icon */
+  --shift-icon-filetree-size: 80%;
+  --shift-icon-filetree-height: 2;
 }
 
 main {
@@ -42,11 +47,17 @@ aside li.collapsed > ul {
 }
 
 aside li.directory::before {
-  content: "+";
+  content: "📁";
+  margin-left: var(--shift-icon-filetree);
+  font-size: var(--shift-icon-filetree-size);
+  line-height: var(--shift-icon-filetree-height);
 }
 
 aside li:not(.collapsed).directory::before {
-  content: "-";
+  content: "📂";
+  margin-left: var(--shift-icon-filetree);
+  font-size: var(--shift-icon-filetree-size);
+  line-height: var(--shift-icon-filetree-height);
 }
 
 aside li.directory {