fix css

src/client/styles/scss/_comment_growi.scss

@@ -34,7 +34,7 @@
 
   .page-comments-row {
     // offset margin left to apply bg-color
-    margin: 30px 0px 30px -15px;
+    margin: 30px -15px 30px -15px;
   }
 
   .page-comments {