How to make svg backgrounds responsible

so i want to make my website responive like this one:
I just dont get it how to do that
Any help?

Here is my site Read-Only:
(how to share your site Read-Only link)

Hi Fabian,

You seem to be on the right track! good work. Your Background acts pretty similar to the one in your example.
How different would you like it to behave?

You’re right, but the laptop and text really don’t do what i want ;=

What is it that you want them to do?