[wp-trac] [WordPress Trac] #49288: Adjust the CSS/JS of the empty metabox holders

[WordPress Trac]

#49288: Adjust the CSS/JS of the empty metabox holders
-----------------------------------------------+---------------------------
 Reporter:  xkon                               |      Owner:  (none)
     Type:  defect (bug)                       |     Status:  new
 Priority:  normal                             |  Milestone:  Awaiting
                                               |  Review
Component:  Administration                     |    Version:
 Severity:  normal                             |   Keywords:
  Focuses:  ui, accessibility, administration  |
-----------------------------------------------+---------------------------
 Splitting this up from #39074. While editing Posts/Pages the `advanced-
 sortables` was missing a visible border and it was of `0px` height so kind
 of hard to even drag a postbox there even if you knew it existed.

 This was unfortunately extended into all metabox holders within the Edit
 so even if the sidebar was emptied there was no indication then that a
 draggable placeholder exists there.

 I've managed to track down changes regarding this back to ticket #26399 &
 changeset [changeset:36295].

 After some investigation, I also realized that the `Drag boxes here` text
 was also hidden from the Dashboard and all other areas for me. This was
 due to the @media rules pointing to specific ranges of a max `1800px`.

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/49288>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform