CSS
width: 500px;
height: 500px;
background:
radial-gradient(ellipse at 50% 50%, rgba(0,0,0,1) 0%, 49%, rgba(0,0,0,0) 50%) 276px 91px / 76px 149px no-repeat no-repeat,
radial-gradient(ellipse at 50% 50%, rgba(0,0,0,1) 0%, 49%, rgba(0,0,0,0) 50%) 152px 91px / 76px 149px no-repeat no-repeat,
radial-gradient(ellipse at 50% 0%, rgba(0,0,0,0) 46%, rgba(0,0,0,1) 47%, 57.5%, rgba(0,0,0,0) 58%) 80px 307px / 342px 142px no-repeat no-repeat,
radial-gradient(ellipse at 50% 50%, rgba(255,234,0,1) 65.9%, 66%, rgba(0,0,0,1) 70%, rgba(0,0,0,0) 70%) 0px 0px / 500px 500px no-repeat no-repeat;