It's smartest to serve jQuery from a content distribution network so your little arduino doesn't have to serve it. Search for "jquery cdn".
Likewise, if your CSS is large, you can serve it from the web somewhere. If it's small, include it inline with the HTML in your server code.
I'd get it working as one big HTML file first, then code it into your arduino server.
thanks for ur reply , i know what your mean ,it could work perfect with internet access,but i'd like to let it perfect work without internet access,i think i have to give up HTML5 and instead use Native App to control it