a {
  background-image: initial;
}

b {
  background-image: inherit;
}

c {
  background-image: unset;
}

d {
  background-image: none;
}

e {
  background-image: none, none;
}

f {
  background-image: url("test.png");
}

g {
  background-image: linear-gradient(45deg, red 10%, green 20px);
}

h {
  background-image: linear-gradient(to top, blue, black);
}

i {
  background-image: linear-gradient(to bottom left, blue, black);
}

j {
  background-image: linear-gradient(yellow, blue);
}

k {
  background-image: repeating-linear-gradient(45deg, red 10%, green 20px);
}

l {
  background-image: repeating-linear-gradient(to top, blue, black);
}

m {
  background-image: repeating-linear-gradient(to bottom left, blue, black);

}

n {
  background-image: repeating-linear-gradient(yellow, blue);
}

o {
  background-image: cross-fade(40% linear-gradient(blue, black), linear-gradient(black, red));
}

p {
  background-image: cross-fade(linear-gradient(blue, black), linear-gradient(black, red));
}

q {
  background-image: cross-fade(40% linear-gradient(blue, black));
}

r {
  background-image: -gtk-icontheme("object-select-symbolic");
}

s {
  background-image: -gtk-scaled(-gtk-icontheme("object-select-symbolic"),linear-gradient(yellow, blue));
}

t {
  background-image: -gtk-gradient(linear, left top, 0 1, from(red), to(green));
}

u {
  background-image: -gtk-gradient(linear, center center, 0.2 bottom, color-stop(0, rgb(0,0,0)), color-stop(0.5, rgb(128,128,128)), color-stop(1, rgb(255,255,255)));
}

v {
  background-image: -gtk-gradient(radial, left top, 0.1, 0 1, 0.3, color-stop(0, black), color-stop(1, blue));
}