body{max-width:760px;margin:5rem auto;padding:0 1.5rem;font:18px/1.7 system-ui;color:#223;background:#f6f7f9}nav a{margin-right:1.5rem;color:#246}h1{font-size:2.4rem;line-height:1.2}small,footer{color:#667}article{background:white;padding:2rem;border-radius:12px}footer{margin-top:3rem}