I'm fourat , front end devlopper , im making a search about extjs before buynig and start use it in a project ! so i'm looking for the detail answer on 2 question because i will use sencha in my work !

* Sencha Ext JS and touch: do we can write a single code and generate for each devices (desktop, tablet and smartphone)?
* Is what we can export a web application developed with ExtJs hybrid application using Apache Cordova or PhoneGap?
* can extjs js work in offline mode ?