body{font-family:system-ui,sans-serif;margin:0;padding:0;background:#f7f7f7}main{max-width:600px;margin:2rem auto;background:#fff;padding:2rem;border-radius:8px;box-shadow:0 2px 8px rgba(0,0,0,.06)}h1,h2{color:#1a202c}a{color:#3182ce;text-decoration:none}nav{margin-bottom:2rem}footer{text-align:center;margin-top:4rem;color:#888}button{background:#3182ce;color:#fff;border:none;border-radius:4px;padding:.5rem 1rem;cursor:pointer;margin-left:1rem}input{padding:.5rem;border:1px solid #d1d5db;border-radius:4px}