How i can create background image in >>>/rus/ board?
How upload custom .css file with picture?
Do you have manual for retards?
I never typed css and html files before.

html {
  background-image: url(endchan 4 2.jpg);
  background-repeat: no-repeat;
  background-position: center center;
  background-attachment: fixed;
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
}