diff --git a/static/css/cours.css b/static/css/cours.css
index 32a49b6..66236ca 100644
--- a/static/css/cours.css
+++ b/static/css/cours.css
@@ -53,18 +53,22 @@ aside li.directory {
   cursor: pointer;
 }
 
+/* Image */
 main img {
   max-width: 100%;
 }
 
+/* Collapse filetree */
 button#menu {
   display: none;
 }
 
+/* Search field */
 input[type="text"] {
   outline: none;
 }
 
+/* breakpoint */
 @media only screen and (max-width: 640px) {
   aside {
     display: none;