Need help Media Query calling different header

I am using a TwentyTwelve Child theme. The location of the wordpress site is http://www.kirstinleanne.com. I have altered the front-page.php template (Front Page Template) from :

get_header();
to
get_header("home");

This works great.

I would like help with adding code to do this:

If the device is max width 480px, then get the regular header.php instead of header-home.php

I would like to know where to put the media query i.e. and code exactly.

Thanks very much!