:root{
  --cyan:#1BA8BE; --cyan-deep:#0E7C93; --cyan-light:#7FD4E0;
  --ink:#1c2b33; --ink-soft:#51636d; --line:#e3edf0; --bg-soft:#f4fafb;
  --navy:#0d2430;
  --radius:14px;
  --shadow:0 10px 40px rgba(14,124,147,.10);
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:"PingFang SC","Microsoft YaHei","Segoe UI",sans-serif;color:var(--ink);background:#fff;line-height:1.75}
img{max-width:100%;display:block}
a{text-decoration:none;color:inherit}
ul{list-style:none}
.container{width:min(1200px,92%);margin:0 auto}
section{padding:80px 0}

.sec-tag{display:inline-flex;align-items:center;gap:8px;color:var(--cyan-deep);font-weight:600;letter-spacing:2px;font-size:14px}
.sec-tag::before{content:"";width:28px;height:2px;background:linear-gradient(90deg,var(--cyan),var(--cyan-light))}
.sec-title{font-size:clamp(26px,3.4vw,40px);font-weight:700;margin:10px 0 18px;letter-spacing:1px}
.sec-sub{color:var(--ink-soft);max-width:760px}
.sec-head{margin-bottom:52px}

/* ===== header ===== */
header{position:fixed;top:0;left:0;right:0;z-index:100;background:rgba(255,255,255,.88);backdrop-filter:blur(14px);border-bottom:1px solid var(--line);transition:box-shadow .3s}
header.scrolled{box-shadow:0 6px 24px rgba(13,36,48,.08)}
.nav{display:flex;align-items:center;justify-content:space-between;height:76px}
.nav .brand{display:flex;align-items:center;gap:12px}
.nav .brand img{height:52px}
.nav ul{display:flex;gap:6px}
.nav ul a{padding:10px 16px;border-radius:8px;font-size:15.5px;font-weight:500;color:var(--ink);transition:.25s}
.nav ul a:hover,.nav ul a.active{color:var(--cyan-deep);background:rgba(27,168,190,.09)}
.burger{display:none;background:none;border:none;cursor:pointer;padding:8px}
.burger span{display:block;width:24px;height:2px;background:var(--ink);margin:5px 0;transition:.3s}

/* ===== page hero (subpage banner) ===== */
.page-hero{position:relative;padding:170px 0 70px;overflow:hidden;
  background:linear-gradient(160deg,#fff 0%,#f2fbfc 50%,#e6f6f9 100%)}
.page-hero::before{content:"";position:absolute;right:-140px;top:50%;transform:translateY(-50%);width:520px;height:520px;border-radius:50%;background:radial-gradient(circle,rgba(27,168,190,.16),transparent 65%)}
.page-hero h1{font-size:clamp(30px,4vw,46px);font-weight:800;letter-spacing:2px;margin:16px 0 10px}
.page-hero .crumb{color:var(--ink-soft);font-size:14px}
.page-hero .crumb a{color:var(--cyan-deep)}

.btn{display:inline-flex;align-items:center;gap:8px;padding:13px 30px;border-radius:999px;font-size:16px;font-weight:600;transition:.3s;cursor:pointer}
.btn-primary{background:linear-gradient(120deg,var(--cyan-deep),var(--cyan));color:#fff;box-shadow:0 12px 30px rgba(14,124,147,.32)}
.btn-primary:hover{transform:translateY(-3px);box-shadow:0 18px 40px rgba(14,124,147,.42)}
.btn-ghost{border:1.5px solid rgba(14,124,147,.4);color:var(--cyan-deep);background:rgba(255,255,255,.6)}
.btn-ghost:hover{background:#fff;transform:translateY(-3px)}

/* reveal */
.reveal{opacity:0;transform:translateY(30px);transition:opacity .7s ease,transform .7s ease}
.reveal.on{opacity:1;transform:none}

/* ===== footer ===== */
footer{background:var(--navy);color:#9db8c2;padding:64px 0 28px;margin-top:0}
.f-grid{display:grid;grid-template-columns:1.3fr 0.9fr 1fr 1.2fr 0.9fr;gap:36px;padding-bottom:44px;border-bottom:1px solid rgba(255,255,255,.1)}
.f-qr{text-align:left}
.f-qr img{width:118px;height:118px;border-radius:10px;background:#fff;padding:6px;margin-bottom:10px}
.f-qr .qr-name{font-size:13.5px;color:#cfe3ea;letter-spacing:1px}
.f-brand img{height:56px;margin-bottom:16px;opacity:.95}
.f-brand p{font-size:13.5px;max-width:320px}
footer h4{color:#fff;font-size:15.5px;margin-bottom:18px;letter-spacing:1px}
footer li{margin-bottom:10px;font-size:13.5px}
footer li a:hover{color:var(--cyan-light)}
.f-bottom{padding-top:24px;display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px;font-size:12.5px;color:#6f8b96}
.f-host{padding-top:16px;font-size:12.5px;color:#8ba2ac;border-top:1px solid rgba(255,255,255,.06);margin-top:4px}
.f-host a{color:#8ba2ac;text-decoration:none}
.f-host a:hover{color:#4fc3e8}

@media (max-width:960px){
  .nav ul{position:fixed;inset:76px 0 auto 0;background:#fff;flex-direction:column;padding:18px 6%;border-bottom:1px solid var(--line);display:none;box-shadow:0 20px 40px rgba(13,36,48,.12)}
  .nav ul.open{display:flex}
  .burger{display:block}
  .f-grid{grid-template-columns:1fr 1fr}
  .f-brand{grid-column:span 2}
  .f-brand img{height:auto;max-height:56px;width:auto}
  .f-qr{grid-column:span 2}
}