Responsive Problem

Responsive Problem

Hello I'm having a problem with the responsiveness of my campaign. 

I created my HTML file on my side. With a mobile version and a desktop version. 
The responsive is done via tags in the head. 

By importing my campaign in Zoho, the responsive doesn't work anymore.
Looking at the code generated by zoho, I saw that it modifies my code. 

How can I prevent that? 

Thanks in advance