I have built a HTML5 website and have just finished a mobile version of the website and looks ok in iphone 4s portrait view but when in landscape view the menu is miles down the page

see link below


I am not 100% sure on how to get it looking ok when in landscape view

Any ideas would be great, I have tried moving the menu down using percentages and that is how I got it looking ok in portrait view

I got the following style for the thumbs li

ul#thumbs, ul#thumbs li{ margin-top: 120px; margin-bottom:470%; padding:0; list-style:none; }
Thank you