IPhone Web Page Compliance

Single web page with a java/CSS based calculator. Looks fine on both safari and ie. However, when viewed on iPhone the descriptive texts get resized which results on overall distortion. I'd like the entire widget to have the same look on all three browsers. On iPhone, it should fill screen and be resizable by user, not automatically. I assume this involves adding a iPhone css file with div's. Project involves explanation of what was done and how to do code this myself in a future browser project.