/* ============ DESIGN TOKENS ============ */
:root{
  --bg:#070b16;
  --bg-2:#0b1120;
  --surface:rgba(255,255,255,.04);
  --surface-2:rgba(255,255,255,.06);
  --border:rgba(255,255,255,.10);
  --text:#e8eef7;
  --muted:#93a1b5;
  --accent:#22d3ee;
  --accent-2:#6366f1;
  --accent-3:#8b5cf6;
  --grad:linear-gradient(120deg,#22d3ee,#818cf8 55%,#a78bfa);
  --radius:16px;
  --maxw:1180px;
  --ease:cubic-bezier(.22,.61,.36,1);
  --nav-h:96px;
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:"PingFang SC","Microsoft YaHei","Segoe UI",system-ui,-apple-system,Inter,Roboto,Helvetica,Arial,sans-serif;
  background:var(--bg);
  color:var(--text);
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
a{color:inherit;text-decoration:none}
img,svg{display:block}
::selection{background:rgba(34,211,238,.3)}

/* ============ NAV ============ */
.nav{
  position:fixed;top:0;left:0;right:0;z-index:50;height:var(--nav-h);
  display:flex;align-items:center;
  transition:background .3s var(--ease),border-color .3s,backdrop-filter .3s;
  border-bottom:1px solid transparent;
}
.nav.scrolled{
  background:rgba(7,11,22,.72);
  backdrop-filter:blur(14px);
  border-bottom:1px solid var(--border);
}
.nav__inner{
  width:100%;max-width:var(--maxw);margin:0 auto;padding:0 24px;
  display:flex;align-items:center;justify-content:space-between;gap:24px;
}
.brand{display:flex;align-items:center;gap:11px}
.brand__logo{height:60px;width:auto;display:block;filter:drop-shadow(0 0 10px rgba(139,92,246,.18))}
.brand__mark{filter:drop-shadow(0 0 12px rgba(34,211,238,.4))}
.nav__links{display:flex;gap:30px}
.nav__links a{font-size:15px;color:var(--muted);position:relative;transition:color .25s}
.nav__links a::after{content:"";position:absolute;left:0;bottom:-6px;width:0;height:2px;background:var(--grad);transition:width .3s var(--ease)}
.nav__links a:hover{color:var(--text)}
.nav__links a:hover::after{width:100%}
.nav__right{display:flex;align-items:center;gap:14px}
.lang{
  background:var(--surface);border:1px solid var(--border);color:var(--text);
  padding:8px 14px;border-radius:999px;font-size:13px;cursor:pointer;transition:.25s;
}
.lang:hover{border-color:var(--accent);color:var(--accent)}
.burger{display:none;flex-direction:column;gap:5px;background:none;border:0;cursor:pointer;padding:6px}
.burger span{width:24px;height:2px;background:var(--text);border-radius:2px;transition:.3s}
.burger.open span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.burger.open span:nth-child(2){opacity:0}
.burger.open span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

/* ============ HERO ============ */
.hero{position:relative;min-height:100vh;display:flex;align-items:center;justify-content:flex-start;text-align:left;padding:120px 24px 80px clamp(28px,9vw,170px);overflow:hidden}
.hero__bg{
  position:absolute;inset:0;z-index:0;
  background:
    linear-gradient(90deg,rgba(7,11,22,.90) 0%,rgba(7,11,22,.87) 24%,rgba(7,11,22,.70) 45%,rgba(7,11,22,.55) 60%,rgba(7,11,22,.16) 72%,rgba(7,11,22,.24) 100%),
    linear-gradient(180deg,rgba(7,11,22,.40),rgba(7,11,22,.14) 42%,rgba(7,11,22,.62)),
    url("../assets/hero-steelmaking.webp") center/cover no-repeat;
}
.hero__arch{position:absolute;top:var(--nav-h);right:0;height:calc(100% - var(--nav-h));width:auto;filter:drop-shadow(0 0 24px rgba(34,211,238,.10))}
@media (max-width:1240px){.hero__arch{opacity:.45}}
@media (max-width:1000px){.hero__arch{display:none}.hero{justify-content:center;text-align:center;padding-left:24px}}
.hero__bg::before{
  content:"";position:absolute;inset:-20%;
  background:
    radial-gradient(40% 50% at 25% 30%,rgba(34,211,238,.18),transparent 60%),
    radial-gradient(45% 55% at 80% 25%,rgba(99,102,241,.20),transparent 60%),
    radial-gradient(50% 60% at 60% 85%,rgba(139,92,246,.16),transparent 60%);
  filter:blur(10px);
  animation:floatBg 16s ease-in-out infinite alternate;
}
.hero__bg::after{
  content:"";position:absolute;inset:0;
  background-image:linear-gradient(rgba(255,255,255,.04) 1px,transparent 1px),linear-gradient(90deg,rgba(255,255,255,.04) 1px,transparent 1px);
  background-size:54px 54px;
  mask-image:radial-gradient(60% 60% at 50% 40%,#000,transparent 75%);
}
@keyframes floatBg{to{transform:translate3d(20px,-18px,0) scale(1.06)}}
.hero__inner{position:relative;z-index:1;max-width:640px}
.hero__eyebrow{display:inline-block;font-size:14px;letter-spacing:2px;color:var(--accent);border:1px solid rgba(34,211,238,.3);padding:6px 16px;border-radius:999px;margin-bottom:26px;background:rgba(34,211,238,.06)}
.hero__title{font-size:clamp(40px,7vw,80px);font-weight:800;line-height:1.08;letter-spacing:-1px;text-shadow:0 2px 22px rgba(7,11,22,.90),0 1px 5px rgba(7,11,22,.95)}
.hero__title span{display:block}
.hero__kicker,.hero__desc{text-shadow:0 1px 14px rgba(7,11,22,.90),0 1px 3px rgba(7,11,22,.95)}
.grad{background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.hero__title .hl{color:#7dd3fc}
.hero__sub{margin:26px 0 0;max-width:560px;font-size:clamp(15px,2vw,18px);color:var(--muted)}
.hero__cta{margin-top:40px;display:flex;gap:16px;justify-content:center;flex-wrap:wrap}
.hero__scroll{position:absolute;bottom:30px;left:50%;transform:translateX(-50%);width:26px;height:42px;border:2px solid var(--border);border-radius:14px;z-index:1}
.hero__scroll span{position:absolute;top:8px;left:50%;width:4px;height:8px;border-radius:2px;background:var(--accent);transform:translateX(-50%);animation:scrollDot 1.6s infinite}
@keyframes scrollDot{0%{opacity:0;transform:translate(-50%,0)}40%{opacity:1}80%{opacity:0;transform:translate(-50%,16px)}}

/* ============ BUTTONS ============ */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:14px 28px;border-radius:999px;font-size:15px;font-weight:600;cursor:pointer;transition:.3s var(--ease);border:1px solid transparent}
.btn--primary{background:linear-gradient(120deg,#22d3ee,#67e8f9);color:#021014;font-weight:700;text-shadow:none;box-shadow:0 10px 30px rgba(34,211,238,.25)}
.btn--primary:hover{transform:translateY(-2px);box-shadow:0 16px 40px rgba(99,102,241,.4)}
.btn--ghost{border-color:var(--border);color:var(--text);background:var(--surface)}
.btn--ghost:hover{border-color:var(--accent);color:var(--accent)}

/* ============ STATS ============ */
.stats{max-width:var(--maxw);margin:0 auto;padding:30px 24px 60px}
.stats__grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:34px 20px;backdrop-filter:blur(8px)}
.stat{text-align:center;position:relative}
.stat::after{content:"";position:absolute;right:-10px;top:10%;height:80%;width:1px;background:var(--border)}
.stat:last-child::after{display:none}
.stat__num{font-size:clamp(30px,4vw,46px);font-weight:800;background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent;display:inline-block}
.stat__plus{font-size:28px;font-weight:800;color:var(--accent);display:inline-block;margin-left:-6px}
.stat__label{color:var(--muted);font-size:14px;margin-top:6px}

/* ============ SECTION ============ */
.section{max-width:var(--maxw);margin:0 auto;padding:90px 24px}
.section__head{text-align:center;max-width:720px;margin:0 auto 56px}
.kicker{font-size:13px;letter-spacing:3px;text-transform:uppercase;color:var(--accent);margin-bottom:14px}
.section__head h2{font-size:clamp(28px,4vw,42px);font-weight:800;letter-spacing:-.5px}
.lead{margin-top:16px;color:var(--muted);font-size:17px}
.journey__body{max-width:820px;margin:0 auto}
.journey__body p{color:#c3cee0;font-size:clamp(15.5px,1.4vw,17px);line-height:2.1;margin-bottom:22px;text-align:justify;letter-spacing:.2px}
.journey__body em{font-style:normal;font-weight:700;background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.journey__quote{position:relative;margin:34px auto 0;max-width:680px;padding:26px 30px;text-align:center;font-size:clamp(17px,2vw,21px);font-weight:700;line-height:1.9;
  background:linear-gradient(135deg,rgba(34,211,238,.08),rgba(139,92,246,.10));
  border:1px solid rgba(139,92,246,.28);border-radius:16px;color:#eaf2ff;
  box-shadow:0 16px 40px rgba(8,14,30,.5)}
.journey__quote::before{content:"\201C";position:absolute;top:-14px;left:18px;font-size:54px;line-height:1;color:rgba(34,211,238,.45)}
.journey__quote::after{content:"\201D";position:absolute;bottom:-26px;right:18px;font-size:54px;line-height:1;color:rgba(139,92,246,.45)}

/* ============ BUSINESS CARDS ============ */
.cards{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:30px 24px;transition:.35s var(--ease);position:relative;overflow:hidden}
.card::before{content:"";position:absolute;inset:0;background:var(--grad);opacity:0;transition:opacity .35s;z-index:0}
.card:hover{transform:translateY(-6px);border-color:transparent}
.card:hover::before{opacity:.08}
.card>*{position:relative;z-index:1}
.card__icon{font-size:30px;margin-bottom:16px;filter:drop-shadow(0 4px 10px rgba(34,211,238,.3))}
.card h3{font-size:19px;margin-bottom:10px}
.card p{color:var(--muted);font-size:14.5px}

/* ============ ABOUT ============ */
.about__grid{display:grid;grid-template-columns:1.15fr .85fr;gap:54px;align-items:center}
.about__text h2{font-size:clamp(26px,3.5vw,38px);font-weight:800;margin:10px 0 18px}
.about__text>p{color:var(--muted);margin-bottom:14px}
.about__values{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin-top:28px}
.value h4{font-size:16px;margin-bottom:6px;color:var(--accent)}
.value p{font-size:13px;color:var(--muted)}
.about__timeline{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:30px}
.field-tags{display:flex;flex-wrap:wrap;gap:12px;margin:18px 0 6px}
.field-tags span{font-size:14px;color:var(--text);border:1px solid var(--border);background:var(--bg-2);padding:9px 16px;border-radius:999px;transition:.25s}
.field-tags span:hover{border-color:var(--accent);color:var(--accent);transform:translateY(-2px)}
.about__note{color:var(--muted);font-size:14.5px;margin-top:14px;line-height:1.7}

/* ============ SOLUTIONS ============ */
.sol{display:grid;gap:18px}
.sol__item{display:flex;gap:26px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:30px 32px;transition:.35s var(--ease)}
.sol__item:hover{border-color:rgba(34,211,238,.4);transform:translateX(6px)}
.sol__no{font-size:34px;font-weight:800;background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent;min-width:54px}
.sol__body h3{font-size:21px;margin-bottom:8px}
.sol__body p{color:var(--muted);max-width:760px}
.tags{list-style:none;display:flex;flex-wrap:wrap;gap:10px;margin-top:14px}
.tags li{font-size:12.5px;color:var(--accent);border:1px solid rgba(34,211,238,.3);background:rgba(34,211,238,.06);padding:5px 12px;border-radius:999px}

/* 产品图库（INSGap） */
.prod-gallery{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:24px}
.prod-stack{display:flex;flex-direction:column;gap:18px}
.prod-fig{margin:0;padding:20px 18px 14px;border-radius:14px;background:rgba(255,255,255,.045);border:1px solid var(--border);display:flex;flex-direction:column;align-items:center;justify-content:center;gap:12px;transition:transform .3s var(--ease),border-color .3s}
.prod-fig:hover{transform:translateY(-4px);border-color:rgba(34,211,238,.4)}
.prod-fig img{width:50%;height:auto;max-width:50%}
.prod-fig--topo img{width:100%;max-width:100%}
.prod-fig figcaption{font-size:13px;color:var(--muted);letter-spacing:1px}

/* 产品元信息（应用领域 / 核心特点 / 型号） */
.sol__meta{display:grid;gap:22px;margin-top:22px;padding-top:22px;border-top:1px dashed var(--border)}
.sol__meta-block{display:grid;gap:10px}
.sol__meta-k{font-size:12px;letter-spacing:2px;text-transform:uppercase;color:var(--accent)}
.field-tags.sm{margin:0}
.field-tags.sm span{font-size:12.5px;padding:6px 13px}
.feat{list-style:none;display:grid;grid-template-columns:1fr 1fr;gap:8px 26px}
.feat li{position:relative;padding-left:18px;font-size:13.5px;color:var(--muted);line-height:1.5}
.feat li::before{content:"";position:absolute;left:0;top:8px;width:7px;height:7px;border-radius:2px;background:var(--grad)}
.models{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}
.model{background:var(--bg-2);border:1px solid var(--border);border-radius:12px;padding:14px 14px;display:flex;flex-direction:column;gap:5px;transition:.25s}
.model:hover{border-color:var(--accent);transform:translateY(-3px)}
.model b{font-size:14px;color:var(--text)}
.model span{font-size:11.5px;color:var(--muted);line-height:1.5}
.sol__item.col-span .models{grid-template-columns:1fr}

/* ============ CASES ============ */
.cases__grid{display:grid;grid-template-columns:1fr 1fr;gap:24px}
.case{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:32px;transition:.35s var(--ease);position:relative;overflow:hidden}
.case::after{content:"";position:absolute;left:0;top:0;width:4px;height:100%;background:var(--grad);opacity:.85}
.case:hover{transform:translateY(-6px);border-color:rgba(34,211,238,.4)}
.case__tag{display:inline-block;font-size:12px;letter-spacing:1px;color:var(--accent);border:1px solid rgba(34,211,238,.3);background:rgba(34,211,238,.06);padding:5px 13px;border-radius:999px;margin-bottom:16px}
.case h3{font-size:21px;margin-bottom:12px;line-height:1.3}
.case>p{color:var(--muted);font-size:14.5px;line-height:1.75}
.case__value{margin-top:20px;padding:16px 18px;background:var(--bg-2);border:1px solid var(--border);border-radius:12px}
.case__value-k{font-size:12px;letter-spacing:1px;text-transform:uppercase;color:var(--accent);display:block;margin-bottom:6px}
.case__value p{font-size:13.5px;color:var(--text);line-height:1.7}

/* 关于-定位 */
.about__positioning{margin-top:20px;padding:16px 18px;background:var(--bg-2);border:1px solid var(--border);border-radius:12px}
.about__positioning p{font-size:14px;color:var(--text)}
.about__positioning b{color:var(--accent)}

/* ============ CONTACT ============ */
.contact__grid{display:grid;grid-template-columns:1fr 1.1fr;gap:40px}
.contact__info{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:34px}
.ci{display:flex;flex-direction:column;gap:4px;padding:16px 0;border-bottom:1px solid var(--border)}
.ci:last-child{border-bottom:0}
.ci__k{font-size:13px;letter-spacing:1px;color:var(--accent);text-transform:uppercase}
.ci__v{font-size:15.5px;color:var(--text)}
.contact__form{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:34px;display:flex;flex-direction:column;gap:18px}
.field{position:relative}
.field input,.field textarea{
  width:100%;background:var(--bg-2);border:1px solid var(--border);border-radius:12px;
  padding:16px 14px;color:var(--text);font-size:15px;font-family:inherit;transition:.25s;resize:vertical;
}
.field input:focus,.field textarea:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px rgba(34,211,238,.12)}
.field label{position:absolute;left:14px;top:16px;color:var(--muted);font-size:15px;pointer-events:none;transition:.2s;background:var(--bg-2);padding:0 4px}
.field input:focus+label,.field input:not(:placeholder-shown)+label,
.field textarea:focus+label,.field textarea:not(:placeholder-shown)+label{top:-9px;font-size:12px;color:var(--accent)}
.form__note{font-size:12.5px;color:var(--muted)}
.form__ok{color:#34d399!important}

/* ============ FOOTER ============ */
.footer{border-top:1px solid var(--border);background:var(--bg-2)}
.footer__inner{max-width:var(--maxw);margin:0 auto;padding:46px 24px;display:flex;flex-wrap:wrap;gap:24px;align-items:center;justify-content:space-between}
.footer__brand{display:flex;flex-direction:column;gap:10px}
.footer__brand strong{font-size:18px}
.footer__brand .brand__logo--footer{height:45px}
.footer__brand span{color:var(--muted);font-size:13px;letter-spacing:2px}
.footer__nav{display:flex;gap:24px;flex-wrap:wrap}
.footer__nav a{color:var(--muted);font-size:14px;transition:color .25s}
.footer__nav a:hover{color:var(--accent)}
.footer__copy{width:100%;color:var(--muted);font-size:13px;text-align:center;margin-top:10px;border-top:1px solid var(--border);padding-top:18px}

/* ============ 产品英文小标 ============ */
.sol__en{display:block;margin-top:3px;font-size:12.5px;letter-spacing:1.5px;color:var(--muted);font-weight:500}

/* ============ 技术架构总览 ============ */
.arch{margin-top:72px;padding-top:56px;border-top:1px solid var(--border)}
.arch__head{text-align:center;max-width:760px;margin:0 auto 40px}
.arch__head h3{font-size:clamp(22px,3vw,30px);font-weight:800;margin-top:10px}
.arch__lead{margin-top:12px;color:var(--muted);font-size:15.5px;line-height:1.75}
.arch__svg{width:100%;height:auto;display:block}
.arch__svg text{font-family:inherit}

/* ============ 为什么选择我们 ============ */
.why__grid{display:grid;grid-template-columns:repeat(4,1fr);gap:22px}
.why__item{
  position:relative;padding:32px 26px 28px;border-radius:var(--radius);
  background:var(--surface);border:1px solid var(--border);
  transition:.35s var(--ease);overflow:hidden;
}
.why__item:hover{transform:translateY(-6px);border-color:rgba(34,211,238,.4);background:var(--surface-2)}
.why__item::before{content:"";position:absolute;left:0;top:0;width:100%;height:3px;background:var(--grad);opacity:.8}
.why__no{font-size:40px;font-weight:800;line-height:1;background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent;margin-bottom:14px}
.why__item h3{font-size:18px;margin-bottom:10px}
.why__item p{font-size:14px;color:var(--muted);line-height:1.75}

/* ============ 案例卡增强 ============ */
.case__meta{margin-top:18px;display:grid;gap:10px}
.case__meta-k{font-size:12px;letter-spacing:2px;text-transform:uppercase;color:var(--accent)}
.case__results{margin-top:18px;padding:16px 18px;background:rgba(34,211,238,.05);border:1px solid rgba(34,211,238,.18);border-radius:12px}
.case__results .feat{margin-top:8px;grid-template-columns:1fr}
.case__cta{
  display:inline-block;margin-top:22px;font-size:13.5px;font-weight:600;color:var(--accent);
  border:1px solid rgba(34,211,238,.35);background:rgba(34,211,238,.06);
  padding:10px 20px;border-radius:999px;transition:.25s var(--ease);
}
.case__cta:hover{background:rgba(34,211,238,.14);transform:translateY(-2px)}

/* ============ REVEAL ANIM ============ */
.reveal{opacity:0;transform:translateY(28px);transition:opacity .7s var(--ease),transform .7s var(--ease)}
.reveal.in{opacity:1;transform:none}

/* ============ RESPONSIVE ============ */
@media(max-width:900px){
  .cards{grid-template-columns:repeat(2,1fr)}
  .stats__grid{grid-template-columns:repeat(2,1fr);gap:30px 16px}
  .stat:nth-child(2)::after{display:none}
  .about__grid{grid-template-columns:1fr;gap:34px}
  .contact__grid{grid-template-columns:1fr}
  .models{grid-template-columns:repeat(2,1fr)}
  .cases__grid{grid-template-columns:1fr}
  .why__grid{grid-template-columns:repeat(2,1fr)}
}
@media(max-width:680px){
  .nav__links{
    position:fixed;top:var(--nav-h);left:0;right:0;flex-direction:column;gap:0;
    background:rgba(7,11,22,.96);backdrop-filter:blur(14px);border-bottom:1px solid var(--border);
    max-height:0;overflow:hidden;transition:max-height .35s var(--ease);
  }
  .nav__links.open{max-height:320px}
  .nav__links a{padding:16px 24px;border-bottom:1px solid var(--border);width:100%}
  .burger{display:flex}
  .cards{grid-template-columns:1fr}
  .stats__grid{grid-template-columns:repeat(2,1fr)}
  .about__values{grid-template-columns:1fr}
  .sol__item{flex-direction:column;gap:10px;padding:24px}
  .prod-gallery{grid-template-columns:1fr}
  .section{padding:64px 20px}
  .feat{grid-template-columns:1fr}
  .models{grid-template-columns:1fr}
  .why__grid{grid-template-columns:1fr}
  .arch{margin-top:48px;padding-top:40px}
}
@media(max-width:680px){
  .journey__body p{font-size:15px;line-height:1.95}
  .journey__quote{font-size:16px;padding:22px 20px}
}