body{font-family:Arial,Helvetica,sans-serif;margin:0;color:#1f2937;background:#fff;line-height:1.6}header{background:#0f172a;color:white;padding:28px 20px;text-align:center}nav{margin-top:12px}nav a{color:white;margin:0 10px;text-decoration:none;font-weight:600}main{max-width:900px;margin:40px auto;padding:0 20px}.card{background:#f8fafc;border:1px solid #e5e7eb;border-radius:14px;padding:24px;margin:20px 0}footer{border-top:1px solid #e5e7eb;margin-top:50px;padding:24px 20px;text-align:center;color:#6b7280}h1,h2{line-height:1.25}.button{display:inline-block;background:#0f172a;color:white;padding:12px 18px;border-radius:10px;text-decoration:none;margin-top:10px}