Really cool idea. Unfortunately, the proportions are somewhat broken on the Oasis (the text bar stretches a bit less than half way across the screen). Was the page designed to be pixel perfect for the Paperwhite?
I used percentages so the text bar and Send button should fill up the full width on any device. I saw the same thing happen before updating the Kindle version. I wonder if they haven't rolled out the upgrade for Oasis yet.