Performance : Only include one style

I had some CSS issues on an older tablet (Android 4.2). I read on the internet that since I need only md style, I should not embed for example ios style in my app.

My www/svg/ folder is full of ios icons, so I guess some css / js for ios are included as well. How can I remove unnecessary images/css/js?

I tried that unsucessfully :

Any help would be grealty appreciated :slight_smile: