diff --git a/assets/css/lesson.scss b/assets/css/lesson.scss
index 05a00a1f4c4d56e5298d0f40082afa0a01559950..abbaecb738f85f74f69134bc3f3d2956faf73570 100644
--- a/assets/css/lesson.scss
+++ b/assets/css/lesson.scss
@@ -159,7 +159,7 @@ span.fold-unfold {
 // keyboard key style, from StackExchange.
 //----------------------------------------
 
-.keyboard {
+kbd {
     display: inline-block;
     margin: 0 .1em;
     padding: .1em .6em;