CSS

Soo Im not the best at CSS at all but Im gonna try and help people because I had a hard time learning it too
first you can just copy this code and put it in your CSS section from Edit profile

body{
background-attachment:fixed;
background-image:url( put the gif URL here );
background-position:center;
background-size:cover;}

copy this with the word body inclusively and the brakets (I made the mistake of not copying them and I didnt know why it didnt work heh) if you want the GIF to not repeat itself (like mine)

The GIF is better from google than pinterest or tumblr and to get the URL you just gotta right click and then click copy image adress :)

I will come back with new codes and explain them to yall ( after someone else explains them to me hxsjkhakhs)

Hope this helped <3