a {
  background-image: radial-gradient(yellow, green);
}

b {
  background-image: radial-gradient(ellipse at center, yellow 0%, green 100%);
}

c {
  background-image: radial-gradient(farthest-corner at 50% 50%, yellow, green);
}

d {
  background-image: radial-gradient(circle, yellow, green);
}

e {
  background-image: radial-gradient(red, yellow, green);
}

f {
  background-image: radial-gradient(farthest-side at left bottom, red, yellow 50px, green);
}

g {
  background-image: radial-gradient(closest-side at 20px 30px, red, yellow, green);
}

h {
  background-image: radial-gradient(20px 30px at 20px 30px, red, yellow, green);
}

i {
  background-image: radial-gradient(closest-side circle at 20px 30px, red, yellow, green);
}

j {
  background-image: radial-gradient(20px 20px at 20px 30px, red, yellow, green);
}