I solved this problem by adding another div as a sibling to the scrolling content div. It's height is set to the radius of the curved borders. There will be design issues if you have content that you want nudged to the very bottom, or text you want to flow into this new div, etc,. but for my UI this thin div is no problem.
The real trick is to have the following structure:
<div class="window">
<div class="title">Some title text</div>
<div class="content">Main content area</div>
<div class="footer"></div>
</div>
Important CSS highlights:
- Your CSS would define the content region with a height and overflow to allow the scrollbar(s) to appear.
- The window class gets the same diameter corners as the title and footer
- The drop shadow, if desired, is only given to the window class
- The height of the footer div is the same as the radius of the bottom corners
Here's what that looks like:
