fix: nav link color

source/css/_partial/article.styl

@@ -240,8 +240,9 @@
 
 .article-nav-title
     font-size: 0.85em
-    line-height: line-height
     margin-top: 0.5em
+    color: color-default
+    line-height: line-height
 
 .article-share-box
     position: absolute