iPad Orientation CSS
For the most part, Mobile Safari on the iPad is the same as that on the iPhone. One difference that I’ve found is that Webkit on the iPad honors CSS media query declarations based on orientation.
I’ve built a sample page demonstrating orientation css for iPad.
Using orientation in CSS is very simple. The code looks like this:
<link rel="stylesheet" media="all and (orientation:portrait)" href="portrait.css">
<link rel="stylesheet" media="all and (orientation:landscape)" href="landscape.css">
Code language: HTML, XML (xml)
In this example, the only difference between the two stylesheets is that they hide one of two headings. The html for the page has the following code:
<h1 id="portrait">You're Viewing in Portrait Mode</h1>
<h1 id="landscape">You're Viewing in Landscape</h1>
Code language: HTML, XML (xml)
The css for portrait.css simply hides the landscape <h1>:
#landscape {display:none}
Code language: CSS (css)
And of course, landscape.css does the opposite.
You can see this css query in current versions of Safari and Firefox on your desktop machine. Simply change the size of your browser window until the height is taller than the width.

Jason Grigsby is one of the co-founders of Cloud Four, Mobile Portland and Responsive Field Day. He is the author of Progressive Web Apps from A Book Apart. Follow him at @grigs.