div{
    width: 80%;
    height: 200px;
    border: 2px solid #333;
    margin: 10px auto;
}

#ex1{
  background:radial-gradient(
  100px 50px at 25% 50%, 
  RGB(240,240,0) 40%, 
  RGB(0,240,160) 60%, 
  RGB(120,0,240));
}
#ex2{
  background:radial-gradient(
  100px 50px at 25% 50%, 
  RGBa(240,240,0,0.5) 40%, 
  RGBa(0,240,160,0.5) 60%, 
  RGBa(120,0,240,0.5));
}
#ex3{
    background:radial-gradient(
	100px 50px at 25% 50%, 
	RGB(240,240,0) 40%, 
	RGB(0,240,160) 60%, 
	RGBa(120,0,240,0)), 
	radial-gradient(
	50px at 75% 50%,  
	RGB(240,240,0) 40%, 
	RGB(0,240,160) 60%, teal
	);
}
#ex4{
    background:radial-gradient(
	100px 50px at 25% 50%, 
	RGB(240,240,0) 40%, 
	RGB(0,240,160) 60%, 
	RGBa(120,0,240,0.5)), 
	url("../images/smilesmall.jpg");
}