CSS for fixing ‘Booking.com’ code – DOMContentLoaded and resize

Hi guys,

I am needing help with CSS for a widget in our footer menu – specifically the Booking.com coding.

I want to execute the Javascript for this widget only after the DOM Content is loaded. I have tried to insert the following code but unfortunately I cannot find where it is I am supposed to do it.

Also, can you please provide the code for automatic resize of this widget when it is accessed from Mobile. I have again tried to do this myself but have failed.

Thanks in advance for your help!

The page I need help with: [log in to see the link]