I want to develop a rather simple app using windows 8 metro style for GUI. But i need this app to have the same appearance, GUI, for both platforms, so that end users that uses it both on PC and a mobile device to have the same visual experience and a flawless navigation.

So, does anyone have knowledge of a Java framework or library to satisfy these needs? Or maybe a method to create a web-based app using HTML, PHP, JScript etc. (maybe something using a local server, on the same machine, because a web server is out of discussion, at least for the moment)? Any idea, method, technology related to the subject is also helpful. And if what you are thinking at can be used for IOS too, the better.