body{font-family:Arial,sans-serif;margin:0;transition:.3s;background:#fff;color:#222}nav{display:flex;justify-content:space-between;padding:16px 24px;position:sticky;top:0;background:#fff}.hero{display:flex;gap:30px;align-items:center;padding:40px;flex-wrap:wrap}.hero img{width:260px;border-radius:16px}section{padding:30px}body.dark{background:#111;color:#eee}body.dark nav{background:#111}button{padding:8px 12px}