move style to default theme

course/learning-mode.css

@@ -41,7 +41,6 @@ body {
 }
 
 .sensei-lms-course-navigation-module__summary {
-	font-family: var(--wp--preset--font-family--system);
 	font-weight: 400;
 	margin-top: 4px;
 	line-height: 16px;

course/theme.json

@@ -670,7 +670,8 @@
 					"padding": {
 						"top": "1rem"
 					}
-				}
+				},
+				"css": "& .sensei-lms-course-navigation-module__summary { font-family: var(--wp--preset--font-family--system); }"
 			},
 			"sensei-lms/course-theme-course-progress-bar": {
 				"color": {