*{box-sizing:border-box}body{margin:0;font-family:-apple-system,Segoe UI,Roboto,sans-serif;color:#1f2937;background:#f8fafc}
header{background:#fff;border-bottom:1px solid #e5e7eb;padding:16px 40px;display:flex;justify-content:space-between;align-items:center}
header b{font-size:20px;color:#2563eb}nav a{margin-left:24px;color:#4b5563;text-decoration:none}nav a:hover{color:#2563eb}
.hero{text-align:center;padding:90px 20px}.hero h1{font-size:40px;margin:0 0 16px}.hero p{color:#6b7280;font-size:18px}
.btn{display:inline-block;margin-top:24px;background:#2563eb;color:#fff;padding:12px 28px;border-radius:8px;text-decoration:none}
.grid{display:flex;gap:24px;justify-content:center;flex-wrap:wrap;padding:0 20px 80px}.card{background:#fff;border:1px solid #e5e7eb;border-radius:12px;padding:28px;width:280px}
.box{max-width:380px;margin:80px auto;background:#fff;border:1px solid #e5e7eb;border-radius:12px;padding:36px}
input{width:100%;padding:12px;margin:8px 0 16px;border:1px solid #d1d5db;border-radius:8px}button{width:100%;padding:12px;background:#2563eb;color:#fff;border:0;border-radius:8px;font-size:15px}
footer{text-align:center;color:#9ca3af;padding:30px;border-top:1px solid #e5e7eb;font-size:14px}