Issue Summary

The card back layout is two columns, with the card description and details on the left column, and the comments and activity on the right column.
When reducing the browser width so that the card back is one column (with the card details at the top, and comments at the bottom), while a draft comment is open, removes the draft.

Steps to Reproduce

1. Open Trello on my laptop, with the browser window at full width of the screen (triggering the two-column card layout)
2. Start typing a comment, and leave that draft in the edit box
3. Shrink my browser window until it's so narrow the view switches to the single-column layout
4. Scroll down to comments and click into the edit box

Expected Results

Draft comment is kept

Actual Results

Draft comment is removed

Workaround

At times, the draft comment can be returned by resizing the window back to full size.