## Issue
5438: Keep floating player in view area
## Changes
- Restore correct z-index
- The bug came as a side effect of cbac2174. Redo cbac2174 to cover both close button and floating player.
- Remove wobbling when dragging to bottom-right.
- The extra gap introduced is fighting against react-draggable. If gaps are needed, handle it entire ourselves or do it somewhere in react-draggable; neither is worth the effort, so the gap was removed.