framework for building cross platform apps

I need a recommendation for a technology stack, preferably java based, javascript based that can help me build an app answering to some of the challenges:

• the app should be primarily web based. 80% percent of the time will be used web based
• the app should also work in offline mode. Let's say a client goes with his laptop, tablet to a location where he does not have internet. The app should be capable to work in offline mode.
• the app should work also work on mobile devices (phones, tablets) native mode.

So, i need some recommendations of some technologies that can answer to this problems. I know that you can build cross platform mobile apps using PhoneGab or derivations of Cordoba, but i don't know if you can build apps with for web and for offline mode.

Thx.