body{font-family:sans-serif;margin:0;padding:2rem;background:#f7f7f7;color:#222;}header,footer{text-align:center;padding:1rem;background:#fff;}nav a{margin:0 0.5rem;color:#00796b;text-decoration:none;}main{max-width:800px;margin:2rem auto;background:#fff;padding:1rem;border-radius:8px;}h1,h2,h3{color:#00796b;}