:root{
  --primary:#0c447c;
  --primary-600:#185fa5;
  --primary-300:#85b7eb;
  --accent:#ef9f27;
  --accent-600:#ba7517;
  --bg:#ffffff;
  --bg-soft:#f4f7fb;
  --bg-dark:#0a2a4a;
  --text:#1f2328;
  --muted:#5f5e5a;
  --border:#e3e8ef;
  --maxw:1180px;
  --radius:12px;
  --shadow:0 6px 22px rgba(12,68,124,.08);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:-apple-system,"Segoe UI","Microsoft YaHei",sans-serif;color:var(--text);line-height:1.7;background:var(--bg);-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.container{max-width:var(--maxw);margin:0 auto;padding:0 20px}
section{padding:72px 0}
.muted{color:var(--muted)}
.center{text-align:center}

/* ---------- Header ---------- */
.header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.92);backdrop-filter:blur(8px);border-bottom:1px solid var(--border)}
.nav{display:flex;align-items:center;justify-content:space-between;height:64px}
.brand{display:flex;align-items:center;gap:10px;font-weight:600;font-size:17px;color:var(--primary)}
.brand .logo{width:34px;height:34px;border-radius:8px;background:linear-gradient(135deg,var(--primary),var(--primary-600));color:#fff;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:15px}
.nav-links{display:flex;gap:28px;align-items:center}
.nav-links a{font-size:15px;color:var(--muted);transition:color .2s}
.nav-links a:hover{color:var(--primary)}
.nav-cta{background:var(--primary);color:#fff;padding:9px 18px;border-radius:8px;font-size:14px;font-weight:500}
.nav-cta:hover{background:var(--primary-600)}
.hamburger{display:none;flex-direction:column;gap:5px;cursor:pointer;background:none;border:0;padding:6px}
.hamburger span{width:24px;height:2px;background:var(--text);border-radius:2px}

/* ---------- Hero ---------- */
.hero{background:linear-gradient(135deg,#0c447c,#0a2a4a);color:#fff;padding:96px 0 84px}
.hero .tag{display:inline-block;background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.25);padding:5px 14px;border-radius:999px;font-size:13px;margin-bottom:18px}
.hero h1{font-size:40px;line-height:1.25;font-weight:600;margin-bottom:18px}
.hero p{font-size:17px;color:rgba(255,255,255,.82);max-width:680px;margin-bottom:30px}
.hero-btns{display:flex;gap:14px;flex-wrap:wrap}
.btn{display:inline-block;padding:13px 26px;border-radius:9px;font-size:15px;font-weight:500;transition:.2s}
.btn-primary{background:var(--accent);color:#1f2328}
.btn-primary:hover{background:#f4b13e}
.btn-ghost{border:1px solid rgba(255,255,255,.4);color:#fff}
.btn-ghost:hover{background:rgba(255,255,255,.1)}
.hero-stats{display:flex;gap:40px;margin-top:54px;flex-wrap:wrap}
.hero-stats .num{font-size:30px;font-weight:700;color:#fff}
.hero-stats .lbl{font-size:13px;color:rgba(255,255,255,.7)}

/* ---------- Section heading ---------- */
.sec-head{text-align:center;max-width:680px;margin:0 auto 44px}
.sec-head .eyebrow{color:var(--accent-600);font-weight:600;font-size:14px;letter-spacing:.5px}
.sec-head h2{font-size:30px;font-weight:600;margin:8px 0 12px;color:var(--primary)}
.sec-head p{color:var(--muted)}

/* ---------- Cards grid ---------- */
.grid{display:grid;gap:22px}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-2{grid-template-columns:repeat(2,1fr)}
.card{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius);padding:26px;box-shadow:var(--shadow);transition:.2s}
.card:hover{transform:translateY(-3px);border-color:var(--primary-300)}
.card .ico{width:46px;height:46px;border-radius:10px;background:var(--bg-soft);color:var(--primary);display:flex;align-items:center;justify-content:center;font-size:22px;margin-bottom:16px}
.card h3{font-size:18px;margin-bottom:8px;color:var(--primary)}
.card p{color:var(--muted);font-size:14px}

/* ---------- Why us ---------- */
.why{background:var(--bg-soft)}
.why .card{background:#fff}

/* ---------- Cases ---------- */
.case{display:grid;grid-template-columns:1fr 1fr;gap:0;border:1px solid var(--border);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);margin-bottom:22px}
.case .meta{padding:30px}
.case .meta .ind{color:var(--accent-600);font-weight:600;font-size:13px}
.case .meta h3{font-size:20px;color:var(--primary);margin:8px 0 14px}
.case .meta p{color:var(--muted);font-size:14px}
.case .result{background:var(--bg-soft);padding:30px;display:flex;flex-direction:column;justify-content:center}
.case .result .row{display:flex;justify-content:space-between;padding:10px 0;border-bottom:1px dashed var(--border);font-size:14px}
.case .result .row:last-child{border:0}
.case .result .row b{color:var(--primary)}

/* ---------- Contact ---------- */
.contact-wrap{display:grid;grid-template-columns:1fr 1fr;gap:40px}
.info-list{list-style:none}
.info-list li{padding:14px 0;border-bottom:1px solid var(--border);display:flex;gap:12px;align-items:flex-start}
.info-list .k{color:var(--primary);font-weight:600;min-width:64px}
.form input,.form textarea{width:100%;padding:12px 14px;border:1px solid var(--border);border-radius:8px;font-size:14px;font-family:inherit;margin-bottom:14px;background:#fff}
.form input:focus,.form textarea:focus{outline:none;border-color:var(--primary-300)}
.form textarea{resize:vertical;min-height:120px}
.form button{background:var(--primary);color:#fff;border:0;padding:13px 26px;border-radius:8px;font-size:15px;cursor:pointer;font-weight:500}
.form button:hover{background:var(--primary-600)}
.form .note{font-size:12px;color:var(--muted);margin-top:8px}

/* ---------- Footer ---------- */
.footer{background:var(--bg-dark);color:rgba(255,255,255,.75);padding:48px 0 28px;font-size:14px}
.footer .cols{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:30px;margin-bottom:30px}
.footer h4{color:#fff;font-size:15px;margin-bottom:14px}
.footer a{color:rgba(255,255,255,.7);display:block;padding:5px 0}
.footer a:hover{color:#fff}
.footer .brand{color:#fff;margin-bottom:12px}
.footer-bottom{border-top:1px solid rgba(255,255,255,.12);padding-top:18px;font-size:13px;color:rgba(255,255,255,.55);text-align:center}
.footer-beian{display:flex;gap:18px;justify-content:center;flex-wrap:wrap;border-top:1px solid rgba(255,255,255,.12);padding-top:14px;margin-top:4px;font-size:13px;color:rgba(255,255,255,.55)}
.footer-beian a{display:inline;padding:0;color:rgba(255,255,255,.6)}
.footer-beian a:hover{color:#fff}

/* ---------- Responsive ---------- */
@media(max-width:900px){
  .grid-3{grid-template-columns:1fr 1fr}
  .case,.contact-wrap{grid-template-columns:1fr}
  .footer .cols{grid-template-columns:1fr 1fr}
}
@media(max-width:640px){
  .nav-links{position:absolute;top:64px;left:0;right:0;background:#fff;flex-direction:column;gap:0;padding:8px 20px 16px;border-bottom:1px solid var(--border);display:none}
  .nav-links.open{display:flex}
  .nav-links a{padding:12px 0;border-bottom:1px solid var(--border);width:100%}
  .hamburger{display:flex}
  .hero h1{font-size:30px}
  .grid-3,.grid-2{grid-template-columns:1fr}
  .footer .cols{grid-template-columns:1fr}
  section{padding:54px 0}
}