<style>@keyframes a{50%{background-position:100% 100%}}@keyframes b{to{background-position:200%}}body{margin:0;background:radial-gradient(circle at 20%30%,#f0f,#0000 40%),radial-gradient(circle at 80%70%,#0ff,#0000 40%),#000;background-size:200% 200%;animation:a 10s linear infinite}h1{font-size:3em;background:linear-gradient(90deg,red,#ff0,#0f0,#0ff,#00f,#f0f,red);background-size:200%;-webkit-background-clip:text;-webkit-text-fill-color:#0000;animation:b 8s linear infinite}</style><h1>안녕하세요</h1>
