/* ============================================================
   深网视迅 · 官网设计系统 site.css
   简洁科技风 · 浅色背景 + 深蓝科技主色 · 系统字体 · 无外部依赖
   ============================================================ */

/* ---------- Design tokens ---------- */
:root{
  --navy:#0F172A;      /* 主深色（标题/页脚背景） */
  --navy-2:#1E293B;
  --slate:#334155;     /* 次级 */
  --blue:#0369A1;      /* 科技蓝 主 CTA */
  --blue-2:#0284C7;
  --blue-3:#0EA5E9;    /* 亮蓝点缀/光晕 */
  --tint:#EFF6FF;      /* 蓝色浅底 */
  --bg:#F8FAFC;        /* 页面背景 */
  --surface:#FFFFFF;   /* 卡片 */
  --text:#0F172A;      /* 正文 */
  --muted:#475569;     /* 次要文字（对比达标） */
  --border:#E2E8F0;    /* 描边 */
  --border-2:#CBD5E1;

  --radius-sm:10px;
  --radius:14px;
  --radius-lg:22px;

  --shadow-sm:0 1px 2px rgba(2,6,23,.06);
  --shadow:0 8px 30px rgba(2,6,23,.08);
  --shadow-lg:0 24px 60px rgba(2,6,23,.14);
  --shadow-blue:0 14px 40px rgba(3,105,161,.28);

  --container:1200px;
  --nav-h:74px;
  --ease:cubic-bezier(.4,0,.2,1);

  --font:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","微软雅黑",Arial,sans-serif;
}

/* ---------- Reset / base ---------- */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{
  font-family:var(--font);
  color:var(--text);
  background:var(--bg);
  font-size:16px;
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
  overflow-x:hidden;
}
img{max-width:100%;height:auto;display:block}
a{color:inherit;text-decoration:none}
ul{list-style:none}
h1,h2,h3,h4,h5{line-height:1.25;color:var(--navy);font-weight:700}
button{font-family:inherit;cursor:pointer;border:none;background:none}
:focus-visible{outline:2px solid var(--blue-2);outline-offset:3px;border-radius:4px}

/* ---------- Layout ---------- */
.container{width:100%;max-width:var(--container);margin:0 auto;padding:0 24px}
.section{padding:88px 0}
.section-tint{background:linear-gradient(180deg,#fff 0%,var(--bg) 100%)}
.section-alt{background:var(--surface)}

/* Section heading (中文标题 + 英文副题) */
.sec-head{text-align:center;max-width:720px;margin:0 auto 52px}
.sec-head .kicker{
  display:inline-block;font-size:13px;letter-spacing:.22em;font-weight:700;
  color:var(--blue);text-transform:uppercase;margin-bottom:14px;
}
.sec-head h2{font-size:clamp(26px,3.4vw,40px);letter-spacing:-.01em}
.sec-head h2 .eng{
  display:block;font-size:15px;letter-spacing:.28em;font-weight:600;
  color:var(--border-2);text-transform:uppercase;margin-top:10px;
}
.sec-head p{margin-top:16px;color:var(--muted);font-size:17px}

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex;align-items:center;gap:9px;
  padding:14px 28px;border-radius:999px;font-weight:600;font-size:15px;
  transition:transform .2s var(--ease),box-shadow .2s var(--ease),background .2s var(--ease);
  will-change:transform;white-space:nowrap;
}
.btn svg{width:18px;height:18px}
.btn-primary{background:var(--blue);color:#fff;box-shadow:var(--shadow-blue)}
.btn-primary:hover{background:var(--blue-2);transform:translateY(-2px)}
.btn-ghost{background:rgba(255,255,255,.08);color:#fff;border:1px solid rgba(255,255,255,.25)}
.btn-ghost:hover{background:rgba(255,255,255,.16);transform:translateY(-2px)}
.btn-outline{background:#fff;color:var(--blue);border:1px solid var(--border-2)}
.btn-outline:hover{border-color:var(--blue);color:var(--blue);transform:translateY(-2px);box-shadow:var(--shadow)}

/* ============================================================
   Header / Nav
   ============================================================ */
.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(255,255,255,.9);
  backdrop-filter:saturate(180%) blur(12px);
  -webkit-backdrop-filter:saturate(180%) blur(12px);
  border-bottom:1px solid transparent;
  transition:box-shadow .25s var(--ease),border-color .25s var(--ease);
}
.site-header.scrolled{box-shadow:0 6px 24px rgba(2,6,23,.07);border-bottom-color:var(--border)}
.nav{display:flex;align-items:center;justify-content:space-between;height:var(--nav-h)}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:20px;color:var(--navy);letter-spacing:-.01em}
.brand img{height:34px;width:auto}
.brand .dot{width:9px;height:9px;border-radius:50%;background:var(--blue-3);box-shadow:0 0 0 4px rgba(14,165,233,.18)}

.nav-menu{display:flex;align-items:center;gap:4px}
.nav-menu>li{position:relative}
.nav-menu>li>a{
  display:inline-flex;align-items:center;gap:6px;
  padding:10px 16px;border-radius:10px;font-weight:600;font-size:15px;color:var(--slate);
  transition:color .2s var(--ease),background .2s var(--ease);
}
.nav-menu>li>a:hover,.nav-menu>li.active>a{color:var(--blue);background:var(--tint)}
.nav-menu .caret{width:14px;height:14px;opacity:.6;transition:transform .2s var(--ease)}
.nav-menu>li:hover .caret{transform:rotate(180deg)}

/* dropdown */
.dropdown-menu{
  position:absolute;top:calc(100% + 8px);left:0;min-width:190px;
  background:#fff;border:1px solid var(--border);border-radius:var(--radius);
  box-shadow:var(--shadow-lg);padding:8px;opacity:0;visibility:hidden;
  transform:translateY(8px);transition:all .2s var(--ease);
}
.nav-menu>li:hover .dropdown-menu,.nav-menu>li:focus-within .dropdown-menu{opacity:1;visibility:visible;transform:translateY(0)}
.dropdown-menu a{display:block;padding:10px 14px;border-radius:9px;font-size:14.5px;color:var(--slate);transition:all .18s var(--ease)}
.dropdown-menu a:hover{background:var(--tint);color:var(--blue)}

.nav-cta{display:inline-flex}
.nav-toggle{display:none;width:44px;height:44px;border-radius:11px;color:var(--navy);align-items:center;justify-content:center}
.nav-toggle:hover{background:var(--tint)}
.nav-toggle svg{width:26px;height:26px}

/* mobile drawer */
.nav-backdrop{position:fixed;inset:0;background:rgba(2,6,23,.5);opacity:0;visibility:hidden;transition:opacity .3s var(--ease);z-index:60}
.nav-backdrop.open{opacity:1;visibility:visible}
.mobile-drawer{
  position:fixed;top:0;right:0;height:100%;width:min(320px,86vw);background:#fff;z-index:70;
  transform:translateX(100%);transition:transform .32s var(--ease);
  box-shadow:-20px 0 60px rgba(2,6,23,.2);display:flex;flex-direction:column;padding:22px;overflow-y:auto;
}
.mobile-drawer.open{transform:translateX(0)}
.drawer-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:18px}
.drawer-close{width:44px;height:44px;border-radius:11px;color:var(--navy);display:flex;align-items:center;justify-content:center}
.drawer-close:hover{background:var(--tint)}
.drawer-close svg{width:24px;height:24px}
.mobile-drawer nav a{display:block;padding:13px 14px;border-radius:10px;font-weight:600;color:var(--slate);font-size:16px}
.mobile-drawer nav a:hover{background:var(--tint);color:var(--blue)}
.mobile-drawer .group-label{font-size:12px;letter-spacing:.14em;text-transform:uppercase;color:var(--border-2);padding:16px 14px 6px;font-weight:700}
.mobile-drawer .btn{margin-top:auto;justify-content:center}

/* ============================================================
   Hero
   ============================================================ */
.hero{
  position:relative;overflow:hidden;color:#fff;
  background:radial-gradient(1100px 520px at 78% -10%,#1d4ed8 0%,transparent 60%),
             linear-gradient(135deg,#0B1220 0%,#0F172A 45%,#0b2447 100%);
}
.hero::before{
  content:"";position:absolute;inset:0;opacity:.5;
  background-image:linear-gradient(rgba(148,163,184,.08) 1px,transparent 1px),
                   linear-gradient(90deg,rgba(148,163,184,.08) 1px,transparent 1px);
  background-size:46px 46px;
  -webkit-mask-image:radial-gradient(720px 420px at 70% 20%,#000,transparent 75%);
          mask-image:radial-gradient(720px 420px at 70% 20%,#000,transparent 75%);
}
.hero .glow{position:absolute;width:520px;height:520px;right:-120px;top:-140px;border-radius:50%;
  background:radial-gradient(circle,rgba(14,165,233,.45),transparent 60%);filter:blur(30px);pointer-events:none}
.hero-inner{position:relative;padding:120px 0 128px;max-width:820px}
.hero .eyebrow{
  display:inline-flex;align-items:center;gap:9px;padding:7px 16px;border-radius:999px;
  background:rgba(255,255,255,.08);border:1px solid rgba(255,255,255,.16);
  font-size:13.5px;font-weight:600;color:#cbd5e1;margin-bottom:26px;letter-spacing:.02em;
}
.hero .eyebrow .dot{width:7px;height:7px;border-radius:50%;background:var(--blue-3);box-shadow:0 0 12px var(--blue-3)}
.hero h1{
  color:#fff;font-size:clamp(34px,5.4vw,58px);line-height:1.12;letter-spacing:-.02em;font-weight:800;
}
.hero h1 .accent{color:#38bdf8}
@supports ((-webkit-background-clip:text) or (background-clip:text)){
  .hero h1 .accent{background:linear-gradient(90deg,#38bdf8,#818cf8);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
}
.hero p{margin-top:24px;font-size:clamp(16px,2vw,19px);line-height:1.8;color:#cbd5e1;max-width:680px}
.hero-actions{margin-top:38px;display:flex;flex-wrap:wrap;gap:14px}
.hero-wave{position:absolute;left:0;right:0;bottom:-1px;line-height:0;color:var(--bg)}
.hero-wave svg{width:100%;height:60px;display:block}

/* ============================================================
   Feature / Service cards
   ============================================================ */
.grid{display:grid;gap:26px}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-2{grid-template-columns:repeat(2,1fr)}

.card{
  background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);
  padding:38px 32px;transition:transform .28s var(--ease),box-shadow .28s var(--ease),border-color .28s var(--ease);
  position:relative;overflow:hidden;
}
.card::after{content:"";position:absolute;left:0;top:0;height:3px;width:100%;
  background:linear-gradient(90deg,var(--blue),var(--blue-3));transform:scaleX(0);transform-origin:left;transition:transform .3s var(--ease)}
.card:hover{transform:translateY(-6px);box-shadow:var(--shadow-lg);border-color:transparent}
.card:hover::after{transform:scaleX(1)}
.card .ico{
  width:60px;height:60px;border-radius:16px;display:flex;align-items:center;justify-content:center;
  background:linear-gradient(135deg,var(--tint),#dbeafe);color:var(--blue);margin-bottom:22px;
}
.card .ico svg{width:28px;height:28px}
.card h3{font-size:21px;margin-bottom:12px}
.card p{color:var(--muted);font-size:15.5px;line-height:1.75}

/* ============================================================
   About
   ============================================================ */
.about-grid{display:grid;grid-template-columns:1.05fr 1fr;gap:60px;align-items:center}
.about-visual{position:relative;border-radius:var(--radius-lg);overflow:hidden;box-shadow:var(--shadow-lg);
  background:linear-gradient(135deg,#0F172A,#0b2447);aspect-ratio:4/3}
.about-visual img{width:100%;height:100%;object-fit:cover;opacity:.92}
.about-visual .badge{
  position:absolute;left:22px;bottom:22px;background:rgba(255,255,255,.95);border-radius:14px;
  padding:14px 20px;box-shadow:var(--shadow);display:flex;align-items:center;gap:12px}
.about-visual .badge .n{font-size:26px;font-weight:800;color:var(--blue);line-height:1}
.about-visual .badge .t{font-size:13px;color:var(--muted)}
.about-copy .kicker{display:inline-block;font-size:13px;letter-spacing:.22em;font-weight:700;color:var(--blue);text-transform:uppercase;margin-bottom:14px}
.about-copy h2{font-size:clamp(25px,3.2vw,36px);margin-bottom:20px;letter-spacing:-.01em}
.about-copy p{color:var(--muted);font-size:16.5px;margin-bottom:16px}
.about-points{margin-top:26px;display:grid;gap:14px}
.about-points li{display:flex;gap:13px;align-items:flex-start;font-size:15.5px;color:var(--slate)}
.about-points .chk{flex:0 0 24px;width:24px;height:24px;border-radius:50%;background:var(--tint);color:var(--blue);display:flex;align-items:center;justify-content:center;margin-top:2px}
.about-points .chk svg{width:14px;height:14px}

/* CTA band */
.cta-band{background:linear-gradient(135deg,#0F172A,#0b2447);border-radius:var(--radius-lg);
  padding:56px;text-align:center;color:#fff;position:relative;overflow:hidden}
.cta-band::before{content:"";position:absolute;width:420px;height:420px;right:-120px;bottom:-160px;border-radius:50%;
  background:radial-gradient(circle,rgba(14,165,233,.4),transparent 60%)}
.cta-band h2{color:#fff;font-size:clamp(24px,3vw,34px);position:relative}
.cta-band p{color:#cbd5e1;margin:14px auto 30px;max-width:560px;position:relative}
.cta-band .btn{position:relative}

/* ============================================================
   Page hero (inner pages)
   ============================================================ */
.page-hero{background:linear-gradient(135deg,#0F172A 0%,#0b2447 100%);color:#fff;position:relative;overflow:hidden}
.page-hero::before{content:"";position:absolute;inset:0;opacity:.5;
  background-image:linear-gradient(rgba(148,163,184,.08) 1px,transparent 1px),linear-gradient(90deg,rgba(148,163,184,.08) 1px,transparent 1px);
  background-size:46px 46px;-webkit-mask-image:radial-gradient(600px 300px at 80% 0,#000,transparent 70%);mask-image:radial-gradient(600px 300px at 80% 0,#000,transparent 70%)}
.page-hero-inner{position:relative;padding:76px 0 66px}
.page-hero .crumb{display:flex;gap:8px;align-items:center;font-size:14px;color:#94a3b8;margin-bottom:16px}
.page-hero .crumb a:hover{color:#fff}
.page-hero h1{color:#fff;font-size:clamp(30px,4.4vw,46px);letter-spacing:-.02em}
.page-hero p{color:#cbd5e1;margin-top:14px;max-width:640px}

/* ============================================================
   Contact
   ============================================================ */
.contact-cards{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;margin-bottom:44px}
.contact-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:30px 26px;text-align:center;transition:transform .25s var(--ease),box-shadow .25s var(--ease)}
.contact-card:hover{transform:translateY(-4px);box-shadow:var(--shadow)}
.contact-card .ico{width:56px;height:56px;border-radius:16px;background:linear-gradient(135deg,var(--tint),#dbeafe);color:var(--blue);display:flex;align-items:center;justify-content:center;margin:0 auto 18px}
.contact-card .ico svg{width:26px;height:26px}
.contact-card h4{font-size:16px;margin-bottom:8px}
.contact-card p{color:var(--muted);font-size:15px;word-break:break-word}
.contact-card a{color:var(--muted)}
.contact-card a:hover{color:var(--blue)}

.form-wrap{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);padding:44px;box-shadow:var(--shadow)}
.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.field{display:flex;flex-direction:column;gap:8px}
.field.full{grid-column:1/-1}
.field label{font-size:14px;font-weight:600;color:var(--slate)}
.field input,.field textarea{
  width:100%;padding:13px 16px;border:1px solid var(--border-2);border-radius:var(--radius-sm);
  font-family:inherit;font-size:15px;color:var(--text);background:#fff;transition:border-color .2s var(--ease),box-shadow .2s var(--ease);
}
.field textarea{min-height:140px;resize:vertical}
.field input:focus,.field textarea:focus{outline:none;border-color:var(--blue-2);box-shadow:0 0 0 4px rgba(2,132,199,.14)}
.field input::placeholder,.field textarea::placeholder{color:#94a3b8}

.map-box{border-radius:var(--radius-lg);overflow:hidden;border:1px solid var(--border);box-shadow:var(--shadow);height:420px}
.map-box #container{width:100%;height:100%}

/* notification */
#notification{visibility:hidden;min-width:240px;background:var(--navy);color:#fff;text-align:center;border-radius:12px;padding:15px 20px;position:fixed;z-index:1000;left:50%;transform:translateX(-50%);top:24px;font-size:15px;box-shadow:var(--shadow-lg)}
#notification.show{visibility:visible;animation:notif-in .35s var(--ease)}
@keyframes notif-in{from{opacity:0;transform:translate(-50%,-14px)}to{opacity:1;transform:translate(-50%,0)}}

/* ============================================================
   Footer
   ============================================================ */
.site-footer{background:var(--navy);color:#cbd5e1;padding:70px 0 0}
.footer-grid{display:grid;grid-template-columns:1.6fr 1fr 1.4fr;gap:48px;padding-bottom:52px}
.site-footer .f-brand{display:flex;align-items:center;gap:10px;margin-bottom:18px}
.site-footer .f-brand img{height:34px}
.site-footer .f-brand span{font-size:20px;font-weight:800;color:#fff}
.site-footer .f-desc{font-size:14.5px;line-height:1.8;max-width:360px;color:#94a3b8}
.site-footer h5{color:#fff;font-size:16px;margin-bottom:20px;font-weight:700}
.site-footer .f-links li{margin-bottom:12px}
.site-footer .f-links a{color:#94a3b8;font-size:14.5px;transition:color .18s var(--ease)}
.site-footer .f-links a:hover{color:#fff}
.f-contact li{display:flex;gap:12px;align-items:flex-start;margin-bottom:16px;font-size:14.5px;color:#94a3b8}
.f-contact svg{width:18px;height:18px;color:var(--blue-3);flex:0 0 18px;margin-top:3px}
.footer-bottom{border-top:1px solid rgba(148,163,184,.15);padding:22px 0;text-align:center;font-size:13.5px;color:#64748b}
.footer-bottom a{color:#94a3b8}
.footer-bottom a:hover{color:#fff}

/* ============================================================
   Back to top
   ============================================================ */
.to-top{position:fixed;right:26px;bottom:26px;width:48px;height:48px;border-radius:14px;background:var(--blue);color:#fff;display:flex;align-items:center;justify-content:center;box-shadow:var(--shadow-blue);opacity:0;visibility:hidden;transform:translateY(14px);transition:all .3s var(--ease);z-index:40}
.to-top.show{opacity:1;visibility:visible;transform:translateY(0)}
.to-top:hover{background:var(--blue-2);transform:translateY(-3px)}
.to-top svg{width:22px;height:22px}

/* ============================================================
   Reveal on scroll
   ============================================================ */
.reveal{opacity:0;transform:translateY(26px);transition:opacity .6s var(--ease),transform .6s var(--ease)}
.reveal.in{opacity:1;transform:none}
.reveal.d1{transition-delay:.08s}
.reveal.d2{transition-delay:.16s}
.reveal.d3{transition-delay:.24s}

/* ============================================================
   Product detail pages
   ============================================================ */
.product-hero{background:linear-gradient(135deg,#0F172A 0%,#0b2447 100%);color:#fff;position:relative;overflow:hidden}
.product-hero::before{content:"";position:absolute;inset:0;opacity:.5;
  background-image:linear-gradient(rgba(148,163,184,.08) 1px,transparent 1px),linear-gradient(90deg,rgba(148,163,184,.08) 1px,transparent 1px);
  background-size:46px 46px;-webkit-mask-image:radial-gradient(760px 400px at 78% 8%,#000,transparent 72%);mask-image:radial-gradient(760px 400px at 78% 8%,#000,transparent 72%)}
.product-hero-inner{position:relative;padding:64px 0;display:grid;grid-template-columns:1.02fr 1fr;gap:52px;align-items:center}
.product-hero .crumb{display:flex;gap:8px;align-items:center;flex-wrap:wrap;font-size:14px;color:#94a3b8;margin-bottom:20px}
.product-hero .crumb a:hover{color:#fff}
.p-logo{width:88px;height:88px;border-radius:22px;background:#fff;box-shadow:var(--shadow-lg);padding:12px;margin-bottom:22px}
.p-logo img{width:100%;height:100%;object-fit:contain;border-radius:12px}
.product-hero h1{color:#fff;font-size:clamp(28px,4vw,44px);letter-spacing:-.02em;line-height:1.15}
.product-hero .tagline{color:#cbd5e1;font-size:clamp(15px,2vw,18px);margin:16px 0 30px;max-width:460px;line-height:1.75}
.p-shot img{width:100%;border-radius:var(--radius-lg);box-shadow:var(--shadow-lg)}

.showcase img{width:100%;border-radius:var(--radius-lg);box-shadow:var(--shadow);display:block}
.showcase.center{max-width:840px;margin:0 auto}

.feature-media{display:grid;grid-template-columns:1fr 1fr;gap:56px;align-items:center}
.feature-media .fm-img img{width:100%;border-radius:var(--radius-lg);box-shadow:var(--shadow)}
.feature-media .kicker{display:inline-block;font-size:13px;letter-spacing:.22em;font-weight:700;color:var(--blue);text-transform:uppercase;margin-bottom:12px}
.feature-media h2{font-size:clamp(23px,3vw,32px);margin-bottom:12px}
.feature-media>div>p{color:var(--muted);font-size:16px}
.feature-list{display:grid;gap:18px;margin-top:24px}
.feature-item{display:flex;gap:16px;align-items:flex-start}
.feature-item .fi-ico{flex:0 0 52px;width:52px;height:52px;border-radius:14px;background:linear-gradient(135deg,var(--tint),#dbeafe);display:flex;align-items:center;justify-content:center;overflow:hidden}
.feature-item .fi-ico img{width:30px;height:30px;object-fit:contain}
.feature-item h4{font-size:16.5px;margin-bottom:3px}
.feature-item p{color:var(--muted);font-size:14.5px;line-height:1.6}

@media (max-width:820px){
  .product-hero-inner{grid-template-columns:1fr;gap:30px;padding:40px 0}
  .feature-media{grid-template-columns:1fr;gap:30px}
  .feature-media .fm-img{order:-1}
}

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width:992px){
  .about-grid{grid-template-columns:1fr;gap:38px}
  .footer-grid{grid-template-columns:1fr 1fr;gap:36px}
  .site-footer .f-brand-col{grid-column:1/-1}
}
@media (max-width:820px){
  .nav-menu,.nav-cta{display:none}
  .nav-toggle{display:flex}
  .section{padding:64px 0}
  .grid-3,.grid-2,.contact-cards{grid-template-columns:1fr}
  .hero-inner{padding:86px 0 96px}
  .cta-band{padding:40px 26px}
  .form-wrap{padding:28px}
  .form-grid{grid-template-columns:1fr}
}
@media (max-width:560px){
  .footer-grid{grid-template-columns:1fr}
  .container{padding:0 18px}
  .btn{padding:13px 22px}
}

/* reduced motion */
@media (prefers-reduced-motion:reduce){
  *{animation-duration:.001ms!important;transition-duration:.001ms!important;scroll-behavior:auto!important}
  .reveal{opacity:1;transform:none}
}