How to add new javascript and css files to T3 XML layout?

To add new CSS & JS files you have to edit the default layout of your template (default.xml) and add the following code just after the layout opening tag

<!--Extra css load for this layout-->
<!--Extra JS load for this layout -->

1- Make sure that the default.xml is your currently selected layout in the profile setings.
2- Make sure that the CSS/JS files that you added to default.xml are already exist in the CSS/JS folders.

Where are listed all other CSS files and Javascripts of the template
The first set of files to be loaded by the template are actually the Framework’s files which are located at

The second set of files to be loaded are the files in the root directory of the template

The last and the highest priority files to be loaded is the template’s theme files