diff --git a/css/books.css b/css/books.css
index baaf0a6..420fa88 100644
--- a/css/books.css
+++ b/css/books.css
@@ -68,6 +68,9 @@ a {
    color: var(--body-bg);
    background-color: var(--pathnav-hover);
 }
+.folder {
+   font-weight: bold;
+}
 .target {
    cursor: pointer;
 }