This example of a div with rounded corners uses 1 image and limited markup.
The image is easily created in Photoshop by:
- Creating a new document that is 2x the radius of the curve of your corners. In this case, 30x30px.
- Set the background colour to the colour of your page. Draw a circle (30x30px) and fill it with the colour of your corners.
- Use the offset filter to shift the image 15 pixels in both directions with Wrap Around selected.
The styles for each corner will shift this 4-corner graphic into the proper position for each instance.