/* ============================================================
   SUPERTEK 官网 · 设计系统 v3「工业科技极简」
   色系：深蓝主色 + 工业灰基底 + 金属银点缀
   —— 科技蓝 #1a479a / 工业灰 #333333 / 深灰 #1A1A1A
   —— 金属银 #E0E0E0 / 纯白 #FFFFFF / 浅灰 #F5F5F5
   交互原则：内容淡入、克制微动效、不浮夸、强化可靠感
   ============================================================ */
:root{
  /* ---- 品牌色（来自设计规范） ---- */
  --blue:#1a479a;            /* 科技蓝 · 主色 */
  --blue-dark:#143a80;       /* 主色加深（hover） */
  --blue-deep:#0F2C63;       /* 深蓝 */
  --blue-tint:#EEF2FA;       /* 蓝色浅底 */
  --blue-tint-2:#DDE5F4;

  --gray-900:#1A1A1A;        /* 深灰 */
  --gray-700:#333333;        /* 工业灰 */
  --gray-500:#555555;
  --gray-400:#7A7A7A;
  --silver:#E0E0E0;          /* 金属银 */
  --gray-100:#F5F5F5;        /* 浅灰 */
  --white:#FFFFFF;

  /* ---- 语义 ---- */
  --bg-dark:#1A1A1A;
  --bg-dark-2:#222222;
  --bg-dark-3:#2A2A2A;
  --bg-light:#FFFFFF;
  --bg-light-2:#F5F5F5;
  --border-light:var(--silver);
  --border-dark:rgba(255,255,255,.14);

  --tx-on-dark:#FFFFFF;
  --tx-on-dark-2:rgba(255,255,255,.72);
  --tx-on-dark-3:rgba(255,255,255,.5);
  --tx-on-light:var(--gray-900);
  --tx-on-light-2:#555555;
  --tx-on-light-3:#7A7A7A;

  /* ---- 字体 ---- */
  --font-cn:"PuHuiTi","PingFang SC","HarmonyOS Sans SC","MiSans","Microsoft YaHei UI","Microsoft YaHei","Hiragino Sans GB","Source Han Sans SC","Noto Sans CJK SC",sans-serif;
  --font-en:"PuHuiTi","PingFang SC","HarmonyOS Sans SC","MiSans","Microsoft YaHei UI","Microsoft YaHei","Hiragino Sans GB","Source Han Sans SC","Noto Sans CJK SC",sans-serif;

  --fs-display:clamp(2.1rem,4.6vw,3.5rem);
  --fs-h2:clamp(1.6rem,3vw,2.3rem);
  --fs-h3:1.15rem;
  --fs-body:1rem;
  --fs-sm:.9rem;
  --fs-xs:.8rem;

  --sec-pad:clamp(4rem,8vw,6.5rem);   /* 大留白 */
  --gap:1.25rem;
  --radius:4px;                        /* 工业风：小圆角、硬朗 */
  --radius-sm:3px;
  --max:1200px;
  --nav-h:72px;
  --ease:cubic-bezier(.4,0,.2,1);
}

*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:var(--font-cn);
  font-size:var(--fs-body);
  line-height:1.7;
  color:var(--tx-on-light);
  background:var(--white);
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;display:block}
a{text-decoration:none;color:inherit}
h1,h2,h3,h4,h5{line-height:1.25;font-weight:700;letter-spacing:0}
button{font-family:inherit;border:none;background:none;cursor:pointer;color:inherit}
ul{list-style:none}
section{position:relative}
.container{max-width:var(--max);margin:0 auto;padding:0 clamp(1.15rem,4vw,2.5rem)}
.section{padding:var(--sec-pad) 0}
.bg-light{background:var(--bg-light-2)}
.bg-white{background:#fff}
.bg-dark{background:var(--bg-dark);color:var(--tx-on-dark)}

/* ---------- 通用文字模块（强层级） ---------- */
.eyebrow{
  display:inline-flex;align-items:center;gap:.6rem;
  font-family:var(--font-en);font-size:.72rem;font-weight:600;
  letter-spacing:.2em;text-transform:uppercase;
  color:var(--blue);margin-bottom:1rem;
}
.eyebrow::before{content:"";width:18px;height:2px;background:var(--blue);flex:0 0 auto}
.eyebrow.on-dark{color:#8FB0E8}
.eyebrow.on-dark::before{background:#8FB0E8}

.section-head{margin-bottom:clamp(2rem,4vw,3rem);max-width:760px}
.section-title{font-size:var(--fs-h2);margin-bottom:.8rem}
.section-sub{color:var(--tx-on-light-2);font-size:1.02rem}
.on-dark .section-sub,.section-sub.on-dark{color:var(--tx-on-dark-2)}

/* 双栏图文（产品/方案详情页） */
.split{display:grid;grid-template-columns:1fr 1fr;gap:clamp(2rem,5vw,3.6rem);align-items:center}
.split.rev .text{order:2}
.split .media{border-radius:var(--radius);overflow:hidden;border:1px solid var(--border-light);background:var(--gray-100);aspect-ratio:16/11}
.split .media img{width:100%;height:100%;object-fit:cover}

/* ============================================================
   按钮体系 —— 不同按钮 = 不同互动方式
   ============================================================ */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.55rem;
  font-size:var(--fs-sm);font-weight:600;line-height:1;
  padding:.9rem 1.6rem;border-radius:var(--radius-sm);
  border:1px solid transparent;
  transition:background .25s var(--ease),color .25s var(--ease),
             border-color .25s var(--ease),transform .25s var(--ease),
             box-shadow .25s var(--ease);
  will-change:transform;white-space:nowrap;
}
.btn:focus-visible{outline:2px solid var(--blue);outline-offset:2px}

/* 1) 主按钮：实心科技蓝 → hover 加深 + 轻浮起 */
.btn-primary{background:var(--blue);color:#fff}
.btn-primary:hover{background:var(--blue-dark);transform:translateY(-2px);box-shadow:0 6px 18px rgba(26,71,154,.25)}

/* 2) 次按钮：工业灰实心 → hover 变深灰 + 轻浮起 */
.btn-secondary{background:var(--gray-700);color:#fff}
.btn-secondary:hover{background:var(--gray-900);transform:translateY(-2px)}

/* 3) 描边按钮（浅底）：银灰描边 → hover 填充科技蓝 */
.btn-outline{border-color:var(--silver);color:var(--gray-900);background:transparent}
.btn-outline:hover{border-color:var(--blue);background:var(--blue);color:#fff;transform:translateY(-2px)}

/* 4) 描边按钮（暗底）：半透明描边 → hover 填充白底深字 */
.btn-outline-dark{border-color:rgba(255,255,255,.3);color:#fff;background:transparent}
.btn-outline-dark:hover{border-color:#fff;background:#fff;color:var(--gray-900);transform:translateY(-2px)}

/* 5) 幽灵文字按钮：文字 + 箭头 → hover 箭头右移 + 下划线展开 */
.btn-ghost{padding:.9rem .2rem;color:var(--gray-900);position:relative}
.btn-ghost .arw{transition:transform .25s var(--ease)}
.btn-ghost::after{content:"";position:absolute;left:.2rem;right:1.6rem;bottom:.55rem;height:1px;background:var(--blue);transform:scaleX(0);transform-origin:left;transition:transform .3s var(--ease)}
.btn-ghost:hover{color:var(--blue)}
.btn-ghost:hover .arw{transform:translateX(4px)}
.btn-ghost:hover::after{transform:scaleX(1)}
.btn-ghost.on-dark{color:#fff}
.btn-ghost.on-dark::after{background:#8FB0E8}
.btn-ghost.on-dark:hover{color:#8FB0E8}

/* 6) 小号 / 大号 / 通栏 */
.btn-sm{padding:.62rem 1.1rem;font-size:var(--fs-xs)}
.btn-lg{padding:1.05rem 2rem;font-size:1rem}
.btn-block{width:100%}

/* 7) 卡片上的「了解更多」链接 */
.link-more{
  display:inline-flex;align-items:center;gap:.45rem;
  font-size:var(--fs-sm);font-weight:600;color:var(--blue);
  transition:gap .25s var(--ease),color .25s var(--ease);
}
.link-more .arw{transition:transform .25s var(--ease)}
.link-more:hover{gap:.7rem;color:var(--blue-dark)}
.link-more:hover .arw{transform:translateX(3px)}

/* 8) 箭头圆钮（返回顶部等） */
.btn-icon{
  width:44px;height:44px;border-radius:50%;display:inline-flex;
  align-items:center;justify-content:center;
  border:1px solid var(--silver);background:#fff;color:var(--gray-900);
  transition:background .25s var(--ease),color .25s var(--ease),border-color .25s var(--ease);
}
.btn-icon:hover{background:var(--blue);border-color:var(--blue);color:#fff}

/* ============================================================
   顶部导航 + 多列下拉
   ============================================================ */
.topbar{background:var(--gray-900);color:var(--tx-on-dark-3);font-size:var(--fs-xs)}
.topbar .container{display:flex;justify-content:space-between;align-items:center;gap:1rem;height:36px}
.topbar a:hover{color:#fff}
.topbar-right{display:flex;gap:1.2rem;align-items:center}

.site-nav{
  position:sticky;top:0;z-index:900;background:#fff;
  border-bottom:1px solid var(--border-light);
  transition:box-shadow .3s var(--ease);
}
.site-nav.scrolled{box-shadow:0 2px 14px rgba(0,0,0,.08)}
.nav-inner{
  max-width:var(--max);margin:0 auto;padding:0 clamp(1.15rem,4vw,2.5rem);
  display:flex;align-items:center;justify-content:space-between;gap:1.5rem;height:var(--nav-h);
}
.brand{display:flex;align-items:center;gap:.7rem;flex:0 0 auto}
.brand img{height:26px}
.brand-cn{font-size:.76rem;color:var(--gray-500);padding-left:.7rem;border-left:1px solid var(--silver);line-height:1.3}

.menu{display:flex;align-items:center;gap:.3rem}
.menu > li{position:relative}
.menu > li > a{
  display:flex;align-items:center;gap:.35rem;
  padding:.6rem .85rem;font-size:var(--fs-sm);font-weight:500;color:var(--gray-900);
  border-radius:var(--radius-sm);transition:color .2s var(--ease),background .2s var(--ease);
}
.menu > li > a:hover,.menu > li.active > a{color:var(--blue);background:var(--blue-tint)}
.caret{width:8px;height:8px;border-right:1.5px solid currentColor;border-bottom:1.5px solid currentColor;transform:rotate(45deg) translateY(-2px);transition:transform .25s var(--ease)}

.dropdown{
  position:absolute;top:100%;left:0;min-width:280px;background:#fff;
  border:1px solid var(--border-light);border-radius:var(--radius);
  box-shadow:0 12px 32px rgba(0,0,0,.1);
  padding:.6rem;opacity:0;visibility:hidden;transform:translateY(6px);
  transition:opacity .2s var(--ease),transform .2s var(--ease),visibility .2s;
}
.menu > li:hover > .dropdown,.menu > li:focus-within > .dropdown{opacity:1;visibility:visible;transform:translateY(0)}
.menu > li:hover .caret{transform:rotate(225deg) translateY(-1px)}
.dropdown a{
  display:block;padding:.62rem .8rem;border-radius:var(--radius-sm);
  font-size:var(--fs-sm);color:var(--gray-700);
  transition:background .2s var(--ease),color .2s var(--ease),padding-left .2s var(--ease);
}
.dropdown a:hover{background:var(--blue-tint);color:var(--blue);padding-left:1.05rem}
.dropdown-label{font-size:var(--fs-xs);color:var(--tx-on-light-3);padding:.5rem .8rem .3rem;letter-spacing:.08em}

.nav-actions{display:flex;align-items:center;gap:.8rem;flex:0 0 auto}
.lang{display:flex;border:1px solid var(--silver);border-radius:var(--radius-sm);overflow:hidden}
.lang a{padding:.3rem .6rem;font-size:var(--fs-xs);color:var(--gray-500);transition:background .2s,color .2s}
.lang a.active,.lang a:hover{background:var(--blue);color:#fff}
.burger{display:none;flex-direction:column;gap:5px;padding:.5rem}
.burger span{width:22px;height:2px;background:var(--gray-900);transition:transform .3s var(--ease),opacity .3s}

/* ============================================================
   页面通用：Hero / 面包屑
   ============================================================ */
.page-hero{background:var(--bg-dark);color:#fff;position:relative;overflow:hidden;padding:clamp(3rem,6vw,5rem) 0}
.page-hero::after{
  content:"";position:absolute;inset:0;
  background-image:linear-gradient(rgba(255,255,255,.045) 1px,transparent 1px),
                   linear-gradient(90deg,rgba(255,255,255,.045) 1px,transparent 1px);
  background-size:56px 56px;-webkit-mask-image:linear-gradient(90deg,#000,transparent 75%);
  mask-image:linear-gradient(90deg,#000,transparent 75%);pointer-events:none;
}
.page-hero .container{position:relative;z-index:1;max-width:900px}
.page-hero h1{font-size:var(--fs-display);margin-bottom:1rem}
.page-hero p{color:var(--tx-on-dark-2);font-size:1.05rem;max-width:640px}
.crumb{display:flex;gap:.5rem;align-items:center;font-size:var(--fs-xs);color:var(--tx-on-dark-3);margin-bottom:1.4rem;flex-wrap:wrap}
.crumb a:hover{color:#fff}
.crumb .sep{opacity:.5}

/* 首页 Hero */
.hero{position:relative;background:var(--bg-dark);color:#fff;overflow:hidden;min-height:min(88vh,760px);display:flex;align-items:center}
.hero-bg{position:absolute;inset:0;z-index:0}
.hero-bg img{width:100%;height:100%;object-fit:cover;opacity:.42;will-change:transform}
.hero-bg::after{content:"";position:absolute;inset:0;background:linear-gradient(90deg,rgba(26,26,26,.95) 0%,rgba(26,26,26,.78) 45%,rgba(26,26,26,.45) 100%)}
.hero .container{position:relative;z-index:2;width:100%;padding-top:clamp(3rem,7vw,5rem);padding-bottom:clamp(3rem,7vw,5rem)}
.hero-copy{max-width:660px}
.hero h1{font-size:var(--fs-display);font-weight:800;margin-bottom:1.2rem}
.hero h1 .accent{color:#8FB0E8}
.hero p.lead{color:var(--tx-on-dark-2);font-size:clamp(1rem,1.5vw,1.12rem);margin-bottom:2rem;max-width:56ch}
.hero-actions{display:flex;gap:.8rem;flex-wrap:wrap}
.hero-facts{
  position:relative;z-index:2;display:grid;grid-template-columns:repeat(4,1fr);
  gap:1.5rem;margin-top:clamp(2.5rem,5vw,3.5rem);padding-top:1.8rem;
  border-top:1px solid var(--border-dark);
}
.hero-facts b{display:block;font-family:var(--font-en);font-size:clamp(1.4rem,2.4vw,1.9rem);font-weight:700;line-height:1.1}
.hero-facts span{font-size:var(--fs-xs);color:var(--tx-on-dark-3)}

/* ============================================================
   卡片 / 网格
   ============================================================ */
.grid{display:grid;gap:var(--gap)}
.g-2{grid-template-columns:repeat(2,1fr)}
.g-3{grid-template-columns:repeat(3,1fr)}
.g-4{grid-template-columns:repeat(4,1fr)}

.card{
  background:#fff;border:1px solid var(--border-light);border-radius:var(--radius);
  padding:1.8rem;transition:transform .3s var(--ease),border-color .3s var(--ease),box-shadow .3s var(--ease);
}
.card:hover{transform:translateY(-3px);border-color:var(--blue);box-shadow:0 10px 26px rgba(0,0,0,.07)}
.card h3{font-size:var(--fs-h3);margin-bottom:.6rem}
.card p{color:var(--tx-on-light-2);font-size:var(--fs-sm)}
.card .num{font-family:var(--font-en);font-size:1.6rem;font-weight:700;color:var(--blue);margin-bottom:.9rem;display:block}

.card-dark{background:var(--bg-dark-2);border:1px solid var(--border-dark);border-radius:var(--radius);padding:1.8rem;transition:transform .3s var(--ease),border-color .3s var(--ease),background .3s var(--ease)}
.card-dark:hover{transform:translateY(-3px);border-color:rgba(255,255,255,.3);background:var(--bg-dark-3)}
.card-dark h3{font-size:var(--fs-h3);margin-bottom:.6rem;color:#fff}
.card-dark p{color:var(--tx-on-dark-2);font-size:var(--fs-sm)}

.pcard{
  display:flex;flex-direction:column;background:#fff;border:1px solid var(--border-light);
  border-radius:var(--radius);overflow:hidden;
  transition:transform .3s var(--ease),border-color .3s var(--ease),box-shadow .3s var(--ease);
}
.pcard:hover{transform:translateY(-3px);border-color:var(--blue);box-shadow:0 12px 30px rgba(0,0,0,.09)}
.pcard-img{aspect-ratio:16/10;overflow:hidden;background:var(--gray-100);border-bottom:1px solid var(--border-light)}
.pcard-img img{width:100%;height:100%;object-fit:cover;transition:transform .5s var(--ease)}
.pcard:hover .pcard-img img{transform:scale(1.04)}
.pcard-body{padding:1.4rem 1.5rem 1.6rem;display:flex;flex-direction:column;gap:.5rem;flex:1}
.pcard-body h3{font-size:1.05rem;color:var(--gray-900)}
.pcard-body p{font-size:var(--fs-sm);color:var(--tx-on-light-2);flex:1}
.pcard .link-more{margin-top:.4rem}

.ico{width:46px;height:46px;border-radius:var(--radius-sm);background:var(--blue-tint);display:flex;align-items:center;justify-content:center;margin-bottom:1.1rem;transition:background .3s var(--ease)}
.ico svg{width:24px;height:24px;fill:none;stroke:var(--blue);stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round;transition:stroke .3s var(--ease)}
.card:hover .ico,.pcard:hover .ico{background:var(--blue)}
.card:hover .ico svg,.pcard:hover .ico svg{stroke:#fff}

/* ============================================================
   数据带 / 规格表 / 时间线 / 表单 / 信息
   ============================================================ */
.metrics{background:var(--blue);color:#fff}
.metrics-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:1.5rem;padding:clamp(2.4rem,4.5vw,3.4rem) 0;text-align:center}
.metric b{display:block;font-family:var(--font-en);font-size:clamp(1.6rem,3.2vw,2.4rem);font-weight:700;line-height:1.1}
.metric span{font-size:var(--fs-xs);color:rgba(255,255,255,.75)}

.spec-table{width:100%;border-collapse:collapse;font-size:var(--fs-sm)}
.spec-table th,.spec-table td{text-align:left;padding:.9rem 1rem;border-bottom:1px solid var(--border-light);vertical-align:top}
.spec-table th{background:var(--gray-100);font-weight:600;color:var(--gray-900);font-size:var(--fs-xs);letter-spacing:.06em;text-transform:uppercase}
.spec-table td:first-child{font-weight:600;color:var(--blue);width:30%}
.spec-table td{color:var(--tx-on-light-2)}
.spec-table tr:hover td{background:var(--blue-tint)}

.feature-list{margin-top:1.4rem}
.feature-list li{display:flex;gap:.9rem;padding:.7rem 0;border-bottom:1px solid var(--border-light);font-size:var(--fs-sm);color:var(--tx-on-light-2);align-items:baseline}
.feature-list li::before{content:"";flex:0 0 auto;width:6px;height:6px;background:var(--blue);margin-top:.55rem}
.feature-list b{color:var(--gray-900);flex:0 0 auto;min-width:8.5em}

.timeline{border-left:1px solid var(--silver);padding-left:1.6rem;margin-top:1.5rem}
.timeline li{position:relative;padding-bottom:1.5rem}
.timeline li::before{content:"";position:absolute;left:-2.05rem;top:.55rem;width:9px;height:9px;background:#fff;border:2px solid var(--blue);border-radius:50%}
.timeline b{font-family:var(--font-en);color:var(--blue);display:block;font-size:var(--fs-sm)}
.timeline p{font-size:var(--fs-sm);color:var(--tx-on-light-2)}

.grid-form{display:grid;grid-template-columns:1fr 1fr;gap:1rem}
.field{display:flex;flex-direction:column;gap:.4rem}
.field.full{grid-column:1 / -1}
.field label{font-size:var(--fs-xs);color:var(--gray-700);font-weight:600}
.field input,.field select,.field textarea{
  font-family:inherit;font-size:var(--fs-sm);color:var(--gray-900);
  padding:.75rem .85rem;border:1px solid var(--silver);border-radius:var(--radius-sm);
  background:#fff;transition:border-color .2s var(--ease),box-shadow .2s var(--ease);width:100%;
}
.field input:focus,.field select:focus,.field textarea:focus{outline:none;border-color:var(--blue);box-shadow:0 0 0 3px var(--blue-tint)}
.field textarea{min-height:120px;resize:vertical}
.form-note{font-size:var(--fs-xs);color:var(--tx-on-light-3);margin-top:1rem}

.info-list li{display:flex;gap:1rem;padding:1rem 0;border-bottom:1px solid var(--border-light);font-size:var(--fs-sm)}
.info-list b{flex:0 0 5.5em;color:var(--gray-900)}
.info-list span{color:var(--tx-on-light-2)}

.badges{display:flex;flex-wrap:wrap;gap:.6rem}
.badges span{font-size:var(--fs-xs);padding:.45rem .9rem;border:1px solid var(--silver);border-radius:99px;color:var(--tx-on-light-2);background:#fff}
.badges.on-dark span{border-color:var(--border-dark);background:rgba(255,255,255,.05);color:var(--tx-on-dark-2)}

/* 待提供占位标记 */
.ph{display:inline-block;font-size:.72rem;line-height:1;padding:.32rem .5rem;border-radius:2px;
    background:rgba(26,71,154,.14);border:1px solid rgba(26,71,154,.55);color:#3E6FD9;font-weight:400;vertical-align:middle}
.on-dark .ph,.site-footer .ph{background:rgba(76,123,232,.16);border-color:rgba(76,123,232,.5);color:#8FB0E8}
.section-sub .ph,.card .ph,.card-dark .ph{font-size:.7rem}

/* ============================================================
   CTA 带
   ============================================================ */
.cta{background:var(--gray-900);color:#fff;padding:clamp(3rem,6vw,4.6rem) 0;position:relative;overflow:hidden}
.cta::after{content:"";position:absolute;right:-8%;top:-60%;width:60%;height:220%;background:linear-gradient(90deg,transparent,rgba(26,71,154,.35));transform:skewX(-14deg);pointer-events:none}
.cta .container{position:relative;z-index:1;display:flex;align-items:center;justify-content:space-between;gap:2rem;flex-wrap:wrap}
.cta h2{font-size:var(--fs-h2);margin-bottom:.5rem}
.cta p{color:var(--tx-on-dark-2);font-size:var(--fs-sm)}

/* ============================================================
   页脚
   ============================================================ */
.site-footer{background:var(--bg-dark);color:var(--tx-on-dark-2);padding:3.5rem 0 0;font-size:var(--fs-sm)}
.footer-grid{display:grid;grid-template-columns:1.6fr 1fr 1fr 1fr;gap:2.2rem;padding-bottom:2.4rem}
.footer-brand img{height:26px;margin-bottom:1rem}
.footer-brand p{color:var(--tx-on-dark-3);font-size:var(--fs-sm);max-width:300px}
.footer-col h5{color:#fff;font-size:var(--fs-sm);margin-bottom:1rem;letter-spacing:.02em}
.footer-col a{display:block;color:var(--tx-on-dark-3);padding:.32rem 0;transition:color .2s var(--ease),padding-left .2s var(--ease)}
.footer-col a:hover{color:#fff;padding-left:4px}
.footer-col p{color:var(--tx-on-dark-3);padding:.28rem 0}
.footer-bottom{border-top:1px solid var(--border-dark);padding:1.2rem 0;display:flex;justify-content:space-between;gap:1rem;flex-wrap:wrap;font-size:var(--fs-xs);color:var(--tx-on-dark-3)}

.to-top{position:fixed;right:22px;bottom:22px;z-index:800}
body.js .to-top{opacity:0;transform:translateY(12px);pointer-events:none;transition:opacity .3s var(--ease),transform .3s var(--ease)}
body.js .to-top.show{opacity:1;transform:translateY(0);pointer-events:auto}

/* ============================================================
   动效（克制：淡入 + 轻浮起）—— 全部由 body.js 门控
   ============================================================ */
.fade{transition:opacity .7s var(--ease),transform .7s var(--ease)}
body.js .fade{opacity:0;transform:translateY(14px)}
body.js .fade.in{opacity:1;transform:translateY(0)}

/* ============================================================
   响应式
   ============================================================ */
@media(max-width:1080px){
  .g-4{grid-template-columns:repeat(2,1fr)}
  .g-3{grid-template-columns:repeat(2,1fr)}
  .metrics-grid{grid-template-columns:repeat(3,1fr)}
  .hero-facts{grid-template-columns:repeat(2,1fr);gap:1.2rem}
  .footer-grid{grid-template-columns:1fr 1fr}

  /* 移动端抽屉 */
  .menu{
    position:fixed;top:var(--nav-h);right:0;
    width:min(86vw,340px);height:calc(100vh - var(--nav-h));
    background:#fff;border-left:1px solid var(--border-light);
    flex-direction:column;align-items:stretch;gap:0;padding:1rem 1.2rem 3rem;
    overflow-y:auto;transform:translateX(102%);
    transition:transform .35s var(--ease);box-shadow:-14px 0 40px rgba(0,0,0,.12);
  }
  .menu.open{transform:translateX(0)}
  .menu > li > a{justify-content:space-between;padding:.9rem .2rem;border-bottom:1px solid var(--gray-100);border-radius:0}
  .dropdown{position:static;opacity:1;visibility:visible;transform:none;box-shadow:none;border:0;min-width:0;padding:.2rem 0 .6rem;display:none}
  .menu > li.open .dropdown{display:block}
  .menu > li.open .caret{transform:rotate(225deg) translateY(-1px)}
  .burger{display:flex}
  .brand-cn{display:none}
  .nav-actions .btn{display:none}
}
@media(max-width:860px){
  .split,.split.rev{grid-template-columns:1fr}
  .split.rev .text{order:0}
  .topbar{display:none}
  .grid-form{grid-template-columns:1fr}
  .cta .container{flex-direction:column;align-items:flex-start}
}
@media(max-width:640px){
  .g-2,.g-3,.g-4{grid-template-columns:1fr}
  .metrics-grid{grid-template-columns:repeat(2,1fr)}
  .footer-grid{grid-template-columns:1fr}
  .hero h1{font-size:clamp(1.8rem,7vw,2.4rem)}
  .hero-facts{grid-template-columns:repeat(2,1fr)}
  .brand img{height:22px}
  .spec-table td:first-child{width:38%}
}

@media (prefers-reduced-motion: reduce){
  *{animation-duration:.01ms !important;transition-duration:.01ms !important;scroll-behavior:auto !important}
}

/* ============================================================
   ★ v4：深色导航（全站）+ 首页沉浸式板块
   ============================================================ */

/* ---- 深色导航（覆盖 v3 的白色导航） ---- */
.site-nav{background:#141414;border-bottom:1px solid rgba(255,255,255,.1)}
.site-nav.scrolled{background:#141414;box-shadow:0 2px 18px rgba(0,0,0,.5)}
.menu > li > a{color:rgba(255,255,255,.76)}
.menu > li > a:hover,.menu > li.active > a{color:#fff;background:rgba(255,255,255,.08)}
.dropdown{background:#1F1F1F;border-color:rgba(255,255,255,.12);box-shadow:0 16px 40px rgba(0,0,0,.5)}
.dropdown a{color:rgba(255,255,255,.72)}
.dropdown a:hover{background:rgba(46,107,255,.18);color:#fff}
.dropdown-label{color:rgba(255,255,255,.4)}
.lang{border-color:rgba(255,255,255,.22)}
.lang a{color:rgba(255,255,255,.6)}
.lang a.active,.lang a:hover{background:var(--blue);color:#fff}
.burger span{background:#fff}
.brand img{height:30px}
/* 首页：导航浮于 Hero 之上，滚动后变实底 */
body.home .site-nav{position:fixed;top:0;left:0;right:0;background:transparent;border-bottom-color:transparent;transition:background .35s var(--ease),border-color .35s var(--ease),box-shadow .35s}
body.home .site-nav.scrolled{background:rgba(16,16,16,.94);backdrop-filter:blur(14px);border-bottom-color:rgba(255,255,255,.1)}
body.home .topbar{display:none}
@media(max-width:1080px){
  .menu{background:#181818;border-left-color:rgba(255,255,255,.1)}
  .menu > li > a{border-bottom-color:rgba(255,255,255,.08)}
}

/* ---- 首页 Hero：4 屏企业优势 · 滚动切换 ---- */
.stage{position:relative;background:#0F0F0F;height:400vh}
.stage-sticky{position:sticky;top:0;height:100vh;overflow:hidden;display:flex;align-items:center}
.stage-slide{position:absolute;inset:0;opacity:0;visibility:hidden;transition:opacity .7s var(--ease),visibility .7s var(--ease)}
.stage-slide.on{opacity:1;visibility:visible}
.stage-bg{position:absolute;inset:0}
.stage-bg img{width:100%;height:100%;object-fit:cover;opacity:.5;transform:scale(1.04)}
.stage-bg::after{content:"";position:absolute;inset:0;background:linear-gradient(90deg,rgba(10,10,10,.96) 0%,rgba(10,10,10,.8) 42%,rgba(10,10,10,.42) 100%)}
.stage-inner{position:relative;z-index:2;width:100%;max-width:var(--max);margin:0 auto;padding:0 clamp(1.15rem,4vw,2.5rem)}
.stage-num{font-family:var(--font-en);font-size:.8rem;font-weight:600;letter-spacing:.24em;color:rgba(255,255,255,.5);margin-bottom:1.1rem}
.stage-kicker{display:inline-block;font-family:var(--font-en);font-size:.74rem;font-weight:600;letter-spacing:.2em;text-transform:uppercase;color:#8FB0E8;border:1px solid rgba(143,176,232,.4);padding:.3rem .7rem;border-radius:2px;margin-bottom:1.2rem}
.stage-slide h2{font-size:clamp(1.9rem,4.2vw,3.3rem);font-weight:800;color:#fff;line-height:1.16;max-width:22ch;margin-bottom:1.1rem}
.stage-slide p{color:rgba(255,255,255,.74);font-size:clamp(1rem,1.5vw,1.1rem);max-width:52ch;margin-bottom:2rem}
.stage-actions{display:flex;gap:.8rem;flex-wrap:wrap}
.stage-ui{position:absolute;left:0;right:0;bottom:clamp(1.6rem,4vh,2.6rem);z-index:3}
.stage-ui .container{display:flex;align-items:center;gap:1.4rem}
.stage-arrow{width:44px;height:44px;border-radius:50%;border:1px solid rgba(255,255,255,.28);color:#fff;display:flex;align-items:center;justify-content:center;font-size:1rem;transition:background .25s var(--ease),border-color .25s var(--ease),color .25s var(--ease);flex:0 0 auto;background:transparent}
.stage-arrow:hover{background:#fff;border-color:#fff;color:#141414}
.stage-dots{display:flex;gap:1.4rem;align-items:center;flex:1;justify-content:center;flex-wrap:wrap}
.stage-dot{font-family:var(--font-en);font-size:.78rem;font-weight:600;letter-spacing:.08em;color:rgba(255,255,255,.4);padding:.3rem .1rem;position:relative;transition:color .3s var(--ease);background:none;border:0;cursor:pointer}
.stage-dot::after{content:"";position:absolute;left:0;right:0;bottom:-4px;height:1.5px;background:var(--blue);transform:scaleX(0);transition:transform .3s var(--ease)}
.stage-dot.on{color:#fff}
.stage-dot.on::after{transform:scaleX(1)}
.stage-progress{width:64px;height:2px;background:rgba(255,255,255,.2);position:relative;flex:0 0 auto}
.stage-progress i{position:absolute;left:0;top:0;height:100%;width:0;background:#fff}

/* ---- 通用：深色区块 ---- */
.dk{background:#0F0F0F;color:#fff}
.dk-2{background:#141414;color:#fff}
.sec-head-dk{max-width:820px;margin-bottom:clamp(2rem,4vw,3rem)}
.sec-head-dk h2{font-size:var(--fs-h2);color:#fff;margin-bottom:.7rem}
.sec-head-dk p{color:rgba(255,255,255,.62)}
.sec-head-dk .eyebrow{color:#8FB0E8}
.sec-head-dk .eyebrow::before{background:#8FB0E8}

/* ---- 产品体系：横向海报轨道 ---- */
.rail-wrap{position:relative}
.rail{display:flex;gap:1.2rem;overflow-x:auto;scroll-snap-type:x mandatory;padding-bottom:1rem;
  scrollbar-width:none;-ms-overflow-style:none}
.rail::-webkit-scrollbar{display:none}
.poster{flex:0 0 clamp(280px,32vw,420px);scroll-snap-align:start;position:relative;border-radius:4px;overflow:hidden;background:#1A1A1A;border:1px solid rgba(255,255,255,.1);transition:border-color .3s var(--ease),transform .3s var(--ease)}
.poster:hover{border-color:var(--blue);transform:translateY(-3px)}
.poster-img{aspect-ratio:3/4;overflow:hidden;position:relative}
.poster-img img{width:100%;height:100%;object-fit:cover;opacity:.72;transition:transform .6s var(--ease),opacity .4s var(--ease)}
.poster:hover .poster-img img{transform:scale(1.05);opacity:.85}
.poster-img::after{content:"";position:absolute;inset:0;background:linear-gradient(180deg,rgba(10,10,10,.25) 0%,rgba(10,10,10,.55) 55%,rgba(10,10,10,.96) 100%)}
.poster-body{position:absolute;left:0;right:0;bottom:0;padding:1.5rem 1.4rem 1.6rem;z-index:2}
.poster-idx{font-family:var(--font-en);font-size:.72rem;font-weight:700;letter-spacing:.2em;color:#8FB0E8;margin-bottom:.55rem}
.poster-body h3{font-size:1.22rem;color:#fff;margin-bottom:.6rem;line-height:1.3}
.poster-body p{font-size:.82rem;color:rgba(255,255,255,.62);line-height:1.6;margin-bottom:.9rem}
.poster-tags{display:flex;flex-wrap:wrap;gap:.35rem}
.poster-tags span{font-size:.68rem;padding:.22rem .5rem;border:1px solid rgba(255,255,255,.2);border-radius:2px;color:rgba(255,255,255,.6)}
.rail-nav{display:flex;gap:.6rem;justify-content:flex-end;margin-top:1.2rem}

/* ---- 行业应用：竖版卡 ---- */
.apps{display:grid;grid-template-columns:repeat(4,1fr);gap:1.1rem}
.app{position:relative;border-radius:4px;overflow:hidden;border:1px solid rgba(255,255,255,.1);aspect-ratio:3/4.4;background:#1A1A1A;transition:border-color .3s var(--ease)}
.app:hover{border-color:var(--blue)}
.app img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;opacity:.6;transition:transform .6s var(--ease),opacity .4s var(--ease)}
.app:hover img{transform:scale(1.05);opacity:.75}
.app::after{content:"";position:absolute;inset:0;background:linear-gradient(180deg,rgba(10,10,10,.1) 0%,rgba(10,10,10,.6) 50%,rgba(10,10,10,.96) 100%)}
.app-body{position:absolute;left:0;right:0;bottom:0;padding:1.4rem 1.3rem;z-index:2}
.app-body h3{font-size:1.02rem;color:#fff;margin-bottom:.45rem;line-height:1.35}
.app-body p{font-size:.78rem;color:rgba(255,255,255,.6);line-height:1.55}
.app-no{position:absolute;top:1.1rem;left:1.2rem;z-index:2;font-family:var(--font-en);font-size:.72rem;font-weight:700;letter-spacing:.18em;color:rgba(255,255,255,.5)}

/* ---- 客户案例：大图 + 缩略图 ---- */
.case-hero{position:relative;border-radius:4px;overflow:hidden;border:1px solid rgba(255,255,255,.1);min-height:clamp(300px,44vw,460px);display:flex;align-items:flex-end;background:#141414}
.case-hero-img{position:absolute;inset:0}
.case-hero-img img{width:100%;height:100%;object-fit:cover;opacity:.85;transition:opacity .5s var(--ease)}
.case-hero::after{content:"";position:absolute;inset:0;background:linear-gradient(90deg,rgba(10,10,10,.9) 0%,rgba(10,10,10,.55) 50%,rgba(10,10,10,.2) 100%)}
.case-hero-body{position:relative;z-index:2;padding:clamp(1.6rem,3.5vw,2.6rem);max-width:620px}
.case-hero-body .tag{display:inline-block;font-family:var(--font-en);font-size:.7rem;font-weight:700;letter-spacing:.16em;color:#8FB0E8;border:1px solid rgba(143,176,232,.45);padding:.28rem .6rem;border-radius:2px;margin-bottom:1rem}
.case-hero-body h3{font-size:clamp(1.2rem,2.4vw,1.7rem);color:#fff;margin-bottom:.8rem;line-height:1.35}
.case-hero-body p{color:rgba(255,255,255,.68);font-size:.92rem;margin-bottom:1.3rem}
.case-thumbs{display:grid;grid-template-columns:repeat(4,1fr);gap:.8rem;margin-top:1rem}
.cthumb{position:relative;border-radius:3px;overflow:hidden;border:1px solid rgba(255,255,255,.12);aspect-ratio:16/10;background:#1A1A1A;cursor:pointer;transition:border-color .3s var(--ease),opacity .3s var(--ease);opacity:.6}
.cthumb.on,.cthumb:hover{border-color:var(--blue);opacity:1}
.cthumb img{width:100%;height:100%;object-fit:cover}
.cthumb span{position:absolute;left:0;right:0;bottom:0;padding:.5rem .6rem;font-size:.72rem;color:#fff;background:linear-gradient(0deg,rgba(0,0,0,.85),transparent)}

/* ---- 合作伙伴 / 资讯 ---- */
.partners{display:flex;flex-wrap:wrap;gap:.7rem}
.partners span{font-size:.85rem;padding:.7rem 1.2rem;border:1px solid rgba(255,255,255,.14);border-radius:3px;color:rgba(255,255,255,.7);background:rgba(255,255,255,.03);transition:border-color .3s var(--ease),color .3s var(--ease)}
.partners span:hover{border-color:var(--blue);color:#fff}
.news-mini{display:grid;grid-template-columns:repeat(3,1fr);gap:1.1rem}
.news-mini a{display:block;border:1px solid rgba(255,255,255,.1);border-radius:4px;padding:1.5rem;background:rgba(255,255,255,.02);transition:border-color .3s var(--ease),transform .3s var(--ease),background .3s var(--ease)}
.news-mini a:hover{border-color:var(--blue);transform:translateY(-3px);background:rgba(255,255,255,.05)}
.news-mini .d{font-family:var(--font-en);font-size:.72rem;letter-spacing:.1em;color:#8FB0E8;margin-bottom:.7rem}
.news-mini h3{font-size:1rem;color:#fff;margin-bottom:.55rem;line-height:1.45}
.news-mini p{font-size:.83rem;color:rgba(255,255,255,.58);margin-bottom:.9rem}
.two-col{display:grid;grid-template-columns:1fr 1fr;gap:clamp(2rem,5vw,3.6rem);align-items:start}

@media(max-width:1080px){
  .apps{grid-template-columns:repeat(2,1fr)}
  .case-thumbs{grid-template-columns:repeat(2,1fr)}
  .news-mini{grid-template-columns:1fr}
  .two-col{grid-template-columns:1fr}
}
@media(max-width:640px){
  .apps{grid-template-columns:1fr}
  .case-thumbs{grid-template-columns:repeat(2,1fr)}
  .stage-dots{gap:.9rem}
  .stage-dot{font-size:.7rem}
  .poster{flex:0 0 86vw}
}