ZK - Open Source Ajax Java Framework

hi all
i want answer to these questions if possible:
--How we declare du CSS in a Zk project ? and where we do that (is in file .zul)
--where we declare a java class and how we call it ?
--how we make templating ?
-- explination about web.xml ?
thx for all

1. in zul, declare <style src="url"/>
2. in zul <window use="this.is.Mywindow">, you can do this to every component declaration.
3. google "ZK EL"
4. you can find a good example inside zkdemo.war