Fix #830 scroll problem.

src/General/Header.coffee

@@ -354,7 +354,7 @@ Header =
   hashScroll: ->
     hash = @location.hash[1..]
     return unless /^p\d+$/.test(hash) and post = $.id hash
-    return if !(post = Get.postFromRoot post) or post.isHidden
+    return if (Get.postFromNode post).isHidden
     Header.scrollTo post
 
   scrollTo: (root, down, needed) ->

src/General/css/layout.css

@@ -437,6 +437,10 @@ nav a,
 }
 #header-bar #scroll-marker {
   display: none;
+  left: 0;
+  right: 0;
+  height: 10px;
+  position: absolute;
 }
 #header-bar:not(.autohide) #scroll-marker {
   pointer-events: none;