## Feat: Add drag and drop support to Upload Style area
Closes#911
---
### Problem
The Upload Style area only supported click-to-upload. Users could not
drag and drop a JSON file directly onto it.
### Fix
Added `onDragOver` and `onDrop` event handlers to the Upload Style area.
The dropped file is passed to the existing file reading logic already
used by the Upload button. A visual highlight is shown when dragging
over the area.
Kanish Jeba Mathew M