Fix delay in custom CSS loading.

src/General/$.coffee

@@ -134,11 +134,11 @@ $.onExists = (root, selector, subtree, cb) ->
       cb el
   observer.observe root, {childList: true, subtree}
 
-$.addStyle = (css, id, test) ->
+$.addStyle = (css, id, test='head') ->
   style = $.el 'style',
     textContent: css
   style.id = id if id?
-  $.asap (-> d.head and (!test? or test())), ->
+  $.onExists doc, test, true, ->
     $.add d.head, style
   style
 

src/Miscellaneous/CustomCSS.coffee

@@ -4,7 +4,7 @@ CustomCSS =
     @addStyle()
 
   addStyle: ->
-    @style = $.addStyle Conf['usercss'], 'custom-css', -> $.id 'fourchanx-css'
+    @style = $.addStyle Conf['usercss'], 'custom-css', '#fourchanx-css'
 
   rmStyle: ->
     if @style