Background image : Support svg

[Purgator]

Hello,

In the Themes settings we are able to chose a custom image as background picture.
I can use an animated gif and it works well.

I want to use an animated svg, but when i select my svg file, it end up displaying a plain white color.

I expect to see the animated svg.

EDIT: I tried with custom CSS and does not works.

EDIT 2 : I had a workaround. I will post a solution for people that are interested.
I'm gonna work a bit more on it before posting.
The result can be :