:root{--ink:#1d2b36;--sea:#1f6f8b;--sand:#f5efe4;--line:#d9d2c3}
*{box-sizing:border-box}body{margin:0;font:17px/1.6 Georgia,serif;color:var(--ink);background:#fff}
.demo{background:#fff3c4;border-bottom:1px solid #e0c870;text-align:center;padding:8px 16px;font:14px/1.4 system-ui,sans-serif}
header,main,footer{max-width:760px;margin:0 auto;padding:16px}
header{display:flex;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:8px;border-bottom:1px solid var(--line)}
.brand{font-size:20px;font-weight:bold;color:var(--sea);text-decoration:none}
nav a{margin-left:14px;color:var(--ink)}h1{font-size:30px;line-height:1.2}
.hero{background:var(--sand);padding:20px;border-radius:8px}
.btn,button{display:inline-block;background:var(--sea);color:#fff;padding:10px 18px;border:0;border-radius:6px;font:inherit;text-decoration:none;cursor:pointer}
label{display:block;margin:12px 0 4px}input,textarea,select{width:100%;padding:8px;font:inherit;border:1px solid var(--line);border-radius:4px}
footer{border-top:1px solid var(--line);color:#5a6872;font-size:14px}img{max-width:100%;height:auto}