lesson.scss: no borders around unrecognized code (#510)

diff --git a/assets/css/lesson.scss b/assets/css/lesson.scss
index 89d5bf77099dcf8c6911d99ac5316d5969ae1a95..182fe3b7374ae66c82224697272fd2c37364818b 100644 (file)
--- a/assets/css/lesson.scss
+++ b/assets/css/lesson.scss
@@ -329,6 +329,12 @@ div.life-cycle {
     background: #d9edf7;
 }
 
+// Remove border around spans of text within code blocks
+// that the highlighter (rouge) failed to recognize.
+pre.highlight span.err {
+    border: none;
+}
+
 
 //----------------------------------------
 // keyboard key style, from StackExchange.