.stars{width:100%;height:100%;background-image:radial-gradient(2px 2px at 20px 30px,#eee,rgba(0,0,0,0)),radial-gradient(2px 2px at 40px 70px,#fff,rgba(0,0,0,0)),radial-gradient(2px 2px at 50px 160px,#ddd,rgba(0,0,0,0)),radial-gradient(2px 2px at 90px 40px,#fff,rgba(0,0,0,0)),radial-gradient(2px 2px at 130px 80px,#fff,rgba(0,0,0,0)),radial-gradient(2px 2px at 160px 120px,#ddd,rgba(0,0,0,0));background-size:200px 200px;background-repeat:repeat;animation:twinkle 5s ease-in-out infinite;opacity:.5}@keyframes twinkle{0%{opacity:.5}50%{opacity:.8}to{opacity:.5}}