Help how do i get the cool backround

hi hi! mesg mee, i have a template for a theme / certain parts of your profile to edit! and if u ever need any help just ask :D

heyyy! if you want just a color you can use :
body{background-color: "your color";
}
if you want pictures or GIFs :
body {
background-image: url("pic/Gif");
} copy and but it in your customise CSS