iPhone website version, recommend working in px or in %? - iphone

Question

I haven't done any iPhone version yet, so I have this question,
In order to be able to browse the website properly -even if the user turns 90º his phone:
Shall i CSS set with's in px or in % ?

Answer 1

If you are programatically targeting the iOS devices such as the iPhone & iTouch then i would use pixels opposed to percentages, but if you are not targeting such devices and want a one stop mobile website for all (most smart-phones) then i would consider using percentages.
you can specificy min-width max-width and min-device-width and max-device-width in your media queries.
Here is a little more about media queries and the combinations that you can do;
/* Target iPhone Portrait */
#media screen and (max-width: 320px) and (orientation: portrait) { body{background:#F0F;} }
/* Target Android Portrait larger than 320px Width */
#media screen and (min-width: 321px) and (max-width: 480px) and (orientation: portrait) { body{background:#F00;} }
/* Target iPhone Landscape */
#media screen and (max-width: 480px) and (orientation: landscape) { body{background:#0F0;} }
/* Target Android Landscape */
#media screen and (min-width: 481px) and (max-width: 800px) and (orientation: landscape) { body{background:#FF0;} }

Answer 2

You can use % with one css class, and the size of components will be adjusted automatically.
You can also use px with two classes, one for portrait, one for landscape :
body[orient="portrait"] {
property: value;
}
body[orient="landscape"] {
property: value;
}

Answer 3

Personally I would use %, rather than px...
You will want the page to become 100% which ever way this is rotated, and then shift the content around accordingly.
The New York Times uses %, as you can see where the page is Landscape you are zoomed in further than Portrait.

Answer 4

If you are building a non specific website for iPhones (sub-domaine like iphone.mywebsite.com) I would suggest using CSS Media Queries as suggested by Xavier. It allows you to do much more than specify a min-width and max-width!
You can specify the type of device (but many devices aren't recognized like they should…) like: screen handheld print tv and many other
But most importantly you can also set if the browser window is in portait or landscape, it's resolution or aspect-ratio and so on…
As for % or px I'd definitely go for px, it's very difficult to have something working as you would wish using %. Because you don't necessarily want the same kind of information if your user comes with an iPhone or with an other device.
For exemple you could take out all the heavy images from your website for iPhone users because they'll probably be using a 3G connection and so making your site a lot faster to load!
A really nice example of what you can do with CSS Media Queries… unfortunately it0s not my work… :-(