div { 
  background-image: radial-gradient(
    40px 60px, 
      circle closest-side, 
        white, black, white
  ); 
}

div { 
  background-image: radial-gradient(
    40px 60px, 
      circle farthest-side, 
        white, black, white
  );
}

div { 
  background-image: radial-gradient(
    40px 60px, 
      circle closest-corner, 
        white, black, white
  ); 
}

div { 
  background-image: radial-gradient(
    40px 60px, 
      circle farthest-corner, 
        white, black, white
  );
}

div { 
  background-image: radial-gradient(
    40px 60px, 
      circle contain, 
        white, black, white
  );
}

div { 
  background-image: radial-gradient(
    40px 60px, 
      circle cover, 
        white, black, white
  );
}

div { 
  background-image: radial-gradient(
    40px 60px, 
      circle 100px 60px, 
        white, black, white
  );
}