Please consider this idea.

totally aggre I hope that incomedia look at this, I know I can change it in the css after the files are exported, unfortunatelly, I modify my site daily and that's not an option to me

Hello Javier,

if you wish to add css to your pages within WebsiteX5 you can do it in step 1 -> expert tab -> add your code in the first text area. In this way you don't have to manually edit your files every time after having exported your site.

Hope this helps