diff --git a/src/themes/buble.styl b/src/themes/buble.styl
index 53fbc152e..c595022ba 100644
--- a/src/themes/buble.styl
+++ b/src/themes/buble.styl
@@ -35,9 +35,12 @@ $sidebar-width = 16rem
   color #333
   font-weight 400
 
+.markdown-section strong
+  color #333
+  font-weight 600
+
 .markdown-section a
   color var(--theme-color, $color-primary)
-  font-weight 400
 
 .markdown-section p, .markdown-section ul, .markdown-section ol
   line-height 1.6rem