Hi Bruno, 

The link below has a valuable starting point for a dynamic style lockdown, although there is lots to be improved.

http://travisepperson.blogspot.com/2015/04/soti-mobicontrol-dynamic-template.html

My suggestion would be to work on understanding the template and then work on converting things to percentages via html/css.

There are also some convenient header and footer macros in that template which are pretty useful for adding images or SOTI macros to be displayed.

Just define different styles for different orientations and screen sizes in a CSS file. Read an introductory book on html/CSS or get help from a colleague with web page design experience.