/* 河南中子星节能科技有限公司 · 官网样式
   纯静态，无外部依赖（无 CDN 字体/脚本），适配国内访问与 3–5 Mbps 小带宽 */

:root{
  --ink:#0c1a20;
  --ink-soft:#2c3b42;
  --body:#46555c;
  --muted:#6f7d83;
  --line:#e2e7e5;
  --paper:#ffffff;
  --paper-2:#f5f7f6;
  --paper-3:#eef2f0;
  --teal:#0d7c82;
  --teal-2:#0a6167;
  --teal-soft:#e6f2f1;
  --ember:#d4622a;
  --ember-soft:#fdf0e6;
  --dark:#0a1418;
  --dark-2:#101e24;
  --radius:14px;
  --radius-lg:22px;
  --shadow-sm:0 1px 2px rgba(12,26,32,.05);
  --shadow:0 18px 40px -24px rgba(12,26,32,.35);
  --container:1160px;
  --ease:cubic-bezier(.22,.61,.36,1);
}

*,*::before,*::after{box-sizing:border-box}

html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}

body{
  margin:0;
  background:var(--paper-2);
  color:var(--body);
  font-family:"PingFang SC","Microsoft YaHei","Noto Sans SC","Source Han Sans SC",system-ui,-apple-system,"Segoe UI",sans-serif;
  font-size:16px;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
}

img,svg{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
h1,h2,h3,h4{color:var(--ink);margin:0;line-height:1.25;letter-spacing:-.01em;font-weight:600}
p{margin:0}
ul{margin:0;padding:0;list-style:none}

.container{width:100%;max-width:var(--container);margin:0 auto;padding:0 24px}

/* ---------- 通用 ---------- */
.eyebrow{
  display:inline-flex;align-items:center;gap:10px;
  font-size:12.5px;letter-spacing:.18em;font-weight:600;
  color:var(--teal);text-transform:uppercase;
}
.eyebrow::before{content:"";width:26px;height:1px;background:currentColor;opacity:.6}
.on-dark .eyebrow{color:#7fd2cd}

.section{padding:92px 0}
.section--tight{padding:68px 0}
.section--paper{background:var(--paper)}
.section--dark{background:var(--dark);color:#b9c6ca}
.section--dark h2,.section--dark h3{color:#f2f6f6}

.section-head{max-width:720px;margin-bottom:44px}
.section-head h2{font-size:clamp(1.65rem,3vw,2.35rem);margin:14px 0 16px}
.section-head p{color:var(--muted);font-size:16.5px}
.section--dark .section-head p{color:#9fb0b5}

.btn{
  display:inline-flex;align-items:center;gap:10px;
  padding:13px 24px;border-radius:999px;
  font-size:15px;font-weight:600;line-height:1;
  border:1px solid transparent;cursor:pointer;
  transition:transform .25s var(--ease),background .25s,color .25s,border-color .25s,box-shadow .25s;
  white-space:nowrap;
}
.btn svg{width:15px;height:15px;flex:none}
.btn--primary{background:var(--teal);color:#fff;box-shadow:0 10px 24px -14px rgba(13,124,130,.9)}
.btn--primary:hover{background:var(--teal-2);transform:translateY(-2px)}
.btn--ghost{background:transparent;color:var(--ink);border-color:var(--line)}
.btn--ghost:hover{border-color:var(--ink);transform:translateY(-2px)}
.btn--on-dark{background:rgba(255,255,255,.08);color:#fff;border-color:rgba(255,255,255,.18)}
.btn--on-dark:hover{background:rgba(255,255,255,.14)}
.btn--sm{padding:10px 18px;font-size:14px}

.link-more{display:inline-flex;align-items:center;gap:8px;font-weight:600;color:var(--teal);font-size:15px}
.link-more svg{width:14px;height:14px;transition:transform .25s var(--ease)}
.link-more:hover svg{transform:translateX(4px)}

.grid{display:grid;gap:22px}
.grid > *{min-width:0}
.grid--3{grid-template-columns:repeat(3,1fr)}
.grid--4{grid-template-columns:repeat(4,1fr)}
.grid--2{grid-template-columns:repeat(2,1fr)}

/* ---------- 顶部导航 ---------- */
.site-header{
  position:sticky;top:0;z-index:60;
  background:rgba(255,255,255,.86);
  backdrop-filter:saturate(1.4) blur(14px);
  -webkit-backdrop-filter:saturate(1.4) blur(14px);
  border-bottom:1px solid transparent;
  transition:border-color .3s,box-shadow .3s;
}
.site-header.is-stuck{border-bottom-color:var(--line);box-shadow:0 6px 24px -20px rgba(12,26,32,.5)}
.header-inner{display:flex;align-items:center;gap:28px;height:72px}

.brand{display:flex;align-items:center;gap:11px;flex:none;color:var(--ink)}
.brand-mark{width:34px;height:34px;color:var(--teal)}
.brand-text{display:flex;flex-direction:column;line-height:1.15}
.brand-text strong{font-size:16.5px;letter-spacing:.02em}
.brand-text small{font-size:9.5px;letter-spacing:.18em;color:var(--muted);font-weight:500}

.nav{display:flex;align-items:center;gap:4px;margin-left:auto}
.nav a{
  position:relative;padding:9px 14px;border-radius:8px;
  font-size:14.5px;color:var(--ink-soft);font-weight:500;
  transition:color .2s,background .2s;
}
.nav a:hover{color:var(--teal);background:var(--teal-soft)}
.nav a.active{color:var(--teal)}
.nav a.active::after{
  content:"";position:absolute;left:50%;bottom:1px;width:18px;height:2px;
  transform:translateX(-50%);
  background:var(--teal);border-radius:2px;
}
.header-cta{flex:none}

.nav-toggle{
  display:none;width:42px;height:42px;margin-left:auto;
  border:1px solid var(--line);background:#fff;border-radius:10px;
  flex-direction:column;align-items:center;justify-content:center;gap:5px;cursor:pointer;
}
.nav-toggle span{display:block;width:18px;height:1.6px;background:var(--ink);transition:transform .25s var(--ease),opacity .2s}
.nav-toggle[aria-expanded="true"] span:nth-child(1){transform:translateY(6.6px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] span:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] span:nth-child(3){transform:translateY(-6.6px) rotate(-45deg)}

/* ---------- 首屏 ---------- */
.hero{
  position:relative;overflow:hidden;
  background:
    radial-gradient(900px 520px at 88% -10%,rgba(212,98,42,.20),transparent 62%),
    radial-gradient(760px 520px at 4% 100%,rgba(13,124,130,.30),transparent 60%),
    var(--dark);
  color:#aebcc1;
  padding:86px 0 74px;
}
.hero::before{
  content:"";position:absolute;inset:0;pointer-events:none;
  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:64px 64px;
  mask-image:radial-gradient(ellipse at 50% 40%,#000 30%,transparent 78%);
  -webkit-mask-image:radial-gradient(ellipse at 50% 40%,#000 30%,transparent 78%);
}
.hero-inner{position:relative;display:grid;grid-template-columns:1.08fr .92fr;gap:56px;align-items:center}
.hero h1{
  color:#fff;font-size:clamp(2.2rem,4.6vw,3.55rem);font-weight:600;
  line-height:1.16;letter-spacing:-.02em;margin:20px 0 22px;
}
.hero h1 em{font-style:normal;color:#8fdcd6}
.hero p.lede{font-size:17px;line-height:1.85;color:#a9b8bd;max-width:33em}
.hero-actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:34px}
.hero-note{display:flex;flex-wrap:wrap;gap:18px;margin-top:30px;font-size:13px;color:#82949a}
.hero-note span{display:inline-flex;align-items:center;gap:7px}
.hero-note i{width:5px;height:5px;border-radius:50%;background:#5fbfb8;display:inline-block}

/* 首屏右侧：系统运行卡片 */
.sys-card{
  position:relative;border:1px solid rgba(255,255,255,.12);border-radius:var(--radius-lg);
  background:linear-gradient(160deg,rgba(255,255,255,.09),rgba(255,255,255,.03));
  padding:26px 26px 22px;
  box-shadow:0 40px 80px -50px rgba(0,0,0,.9);
  backdrop-filter:blur(6px);
}
.sys-card h2{color:#fff;font-size:15px;font-weight:600;letter-spacing:.04em;margin-bottom:4px}
.sys-card .sys-sub{font-size:12.5px;color:#82949a;margin-bottom:22px}
.sys-steps{display:flex;flex-direction:column;gap:0}
.sys-step{position:relative;display:grid;grid-template-columns:34px 1fr;gap:14px;padding-bottom:22px}
.sys-step:last-child{padding-bottom:0}
.sys-step::before{
  content:"";position:absolute;left:16px;top:34px;bottom:2px;width:1px;
  background:linear-gradient(rgba(255,255,255,.22),rgba(255,255,255,.04));
}
.sys-step:last-child::before{display:none}
.sys-idx{
  width:34px;height:34px;border-radius:50%;flex:none;
  display:grid;place-items:center;font-size:12px;font-weight:600;
  color:#9de6e0;border:1px solid rgba(157,230,224,.35);background:rgba(13,124,130,.22);
}
.sys-step h3{color:#eef6f5;font-size:14.5px;font-weight:600;margin-bottom:3px}
.sys-step p{font-size:12.8px;color:#8ba0a5;line-height:1.65}
.sys-foot{
  margin-top:20px;padding-top:16px;border-top:1px solid rgba(255,255,255,.1);
  display:flex;justify-content:space-between;gap:12px;font-size:11.5px;color:#7d9095;
}
.sys-foot b{color:#c9d8da;font-weight:600}
.sys-badge{
  position:absolute;right:-14px;top:-16px;
  background:var(--ember);color:#fff;font-size:11.5px;font-weight:600;
  padding:8px 14px;border-radius:999px;
  box-shadow:0 14px 30px -16px rgba(212,98,42,.9);
}

/* ---------- 数据带 ---------- */
.metrics{background:var(--paper);border-bottom:1px solid var(--line)}
.metrics-grid{display:grid;grid-template-columns:repeat(4,1fr)}
.metric{padding:34px 8px;text-align:center;border-left:1px solid var(--line)}
.metric:first-child{border-left:0}
.metric b{display:block;font-size:clamp(1.7rem,3vw,2.4rem);color:var(--ink);font-weight:600;letter-spacing:-.02em;line-height:1.1}
.metric b small{font-size:.48em;font-weight:600;color:var(--teal);margin-left:4px;letter-spacing:0}
.metric span{display:block;margin-top:8px;font-size:13px;color:var(--muted)}

/* ---------- 卡片 ---------- */
.card{
  position:relative;background:var(--paper);border:1px solid var(--line);
  border-radius:var(--radius);padding:28px 26px 26px;
  transition:transform .3s var(--ease),box-shadow .3s,border-color .3s;
  overflow:hidden;
}
.card::after{
  content:"";position:absolute;left:0;top:0;height:2px;width:100%;
  background:linear-gradient(90deg,var(--teal),transparent 70%);
  opacity:0;transition:opacity .3s;
}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow);border-color:#cfdad7}
.card:hover::after{opacity:1}
.card-idx{
  display:inline-block;font-size:11.5px;letter-spacing:.16em;color:var(--teal);
  font-weight:600;margin-bottom:16px;
}
.card h3{font-size:18px;margin-bottom:10px}
.card p{font-size:14.5px;color:var(--body)}
.card ul{margin-top:16px;display:flex;flex-direction:column;gap:8px}
.card li{position:relative;padding-left:16px;font-size:13.5px;color:var(--muted)}
.card li::before{content:"";position:absolute;left:0;top:.72em;width:5px;height:5px;border-radius:50%;background:var(--teal);opacity:.55}
.card-icon{
  width:42px;height:42px;border-radius:11px;display:grid;place-items:center;
  background:var(--teal-soft);color:var(--teal);margin-bottom:18px;
}
.card-icon svg{width:20px;height:20px}

/* ---------- 核心系统（深色分栏） ---------- */
.feature{
  border-radius:var(--radius-lg);overflow:hidden;
  background:linear-gradient(135deg,#0b171c,#122329 70%);
  color:#a9b8bd;display:grid;grid-template-columns:1.04fr .96fr;
}
.feature-main{padding:44px 42px;display:flex;flex-direction:column;justify-content:center}
.feature-main h2{color:#fff;font-size:clamp(1.5rem,2.4vw,2rem);margin:14px 0 16px}
.feature-main p{color:#9fb0b5;font-size:15px}
.feature-side{
  padding:44px 38px;border-left:1px solid rgba(255,255,255,.08);
  background:rgba(255,255,255,.02);
}
.feature-side h3{color:#dfeaea;font-size:13px;letter-spacing:.14em;text-transform:uppercase;margin-bottom:20px}
.pain-list{display:flex;flex-direction:column;gap:0}
.pain{display:flex;gap:13px;padding:14px 0;border-bottom:1px solid rgba(255,255,255,.07)}
.pain:last-child{border-bottom:0}
.pain svg{width:17px;height:17px;flex:none;color:#7fd2cd;margin-top:3px}
.pain b{display:block;color:#e7f0ef;font-size:14px;font-weight:600;margin-bottom:2px}
.pain span{font-size:12.8px;color:#8ba0a5;line-height:1.6}
.feature-note{
  margin-top:22px;padding:14px 16px;border-radius:10px;
  background:rgba(212,98,42,.12);border:1px solid rgba(212,98,42,.28);
  font-size:12.5px;color:#e8b795;line-height:1.7;
}

/* ---------- 产品矩阵 ---------- */
.matrix{border-top:1px solid var(--line)}
.matrix-row{
  display:grid;grid-template-columns:56px minmax(0,1.15fr) minmax(0,1.6fr) 122px;
  gap:20px;align-items:center;
  padding:22px 6px;border-bottom:1px solid var(--line);
  transition:background .25s,padding .25s;
}
.matrix-row:hover{background:var(--paper);padding-left:14px;padding-right:14px}
.matrix-num{font-size:12px;font-weight:600;color:var(--teal);letter-spacing:.06em}
.matrix-row h3{font-size:16px;font-weight:600}
.matrix-row p{font-size:13.5px;color:var(--muted);margin-top:2px}
.tag{
  justify-self:end;font-size:11.5px;font-weight:600;letter-spacing:.04em;
  padding:4px 10px;border-radius:999px;border:1px solid var(--line);
  color:var(--ink-soft);background:var(--paper-2);white-space:nowrap;
}
.tag--ip{color:#a4511f;background:var(--ember-soft);border-color:#f3d6c2}
.tag--sys{color:var(--teal-2);background:var(--teal-soft);border-color:#c9e3e1}
.tag--co{color:#4a5a63;background:#eef1f3;border-color:#dde3e6}

/* ---------- 应用与成果 ---------- */
.result-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.result{
  background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);
  padding:26px 24px;
}
.result b{display:block;font-size:15px;color:var(--ink);margin-bottom:8px}
.result p{font-size:13.5px;color:var(--muted)}
.result-num{font-size:12px;color:var(--ember);font-weight:600;letter-spacing:.1em;margin-bottom:12px;display:block}

.quote{
  display:grid;grid-template-columns:auto 1fr;gap:26px;align-items:start;
  padding:34px 36px;border-radius:var(--radius-lg);
  background:var(--teal-soft);border:1px solid #d3e8e6;
}
.quote-mark{font-size:52px;line-height:.8;color:var(--teal);opacity:.35;font-family:Georgia,serif}
.quote p{font-size:16.5px;color:#22484b;line-height:1.8}

/* ---------- 合作 / 资质 ---------- */
.logo-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}
.logo-item{
  background:var(--paper);border:1px solid var(--line);border-radius:12px;
  padding:22px 18px;text-align:center;
}
.logo-item b{display:block;font-size:14.5px;color:var(--ink)}
.logo-item span{display:block;font-size:12px;color:var(--muted);margin-top:4px}

.honor{display:grid;grid-template-columns:1.15fr .85fr;gap:22px;align-items:stretch}
.honor-list{display:flex;flex-direction:column;gap:12px}
.honor-item{
  display:flex;gap:16px;align-items:flex-start;
  background:var(--paper);border:1px solid var(--line);border-radius:12px;padding:18px 20px;
}
.honor-item b{display:block;font-size:14.5px;color:var(--ink)}
.honor-item span{font-size:13px;color:var(--muted)}
.honor-item svg{width:20px;height:20px;flex:none;color:var(--ember);margin-top:2px}
.honor-visual{
  border-radius:var(--radius);border:1px solid var(--line);
  background:
    radial-gradient(420px 240px at 90% 0%,rgba(212,98,42,.12),transparent 60%),
    radial-gradient(360px 240px at 0% 100%,rgba(13,124,130,.14),transparent 60%),
    var(--paper);
  padding:32px;display:flex;flex-direction:column;justify-content:space-between;
}
.honor-visual .big{font-size:clamp(1.6rem,3vw,2.2rem);color:var(--ink);font-weight:600;line-height:1.25}
.honor-visual p{font-size:13.5px;color:var(--muted);margin-top:10px}
.honor-visual .meta{font-size:12px;letter-spacing:.12em;color:var(--teal);text-transform:uppercase;margin-top:26px}

/* ---------- CTA 带 ---------- */
.cta-band{
  border-radius:var(--radius-lg);padding:52px 48px;
  background:
    radial-gradient(700px 320px at 100% 0%,rgba(212,98,42,.22),transparent 60%),
    radial-gradient(600px 320px at 0% 100%,rgba(13,124,130,.34),transparent 60%),
    var(--dark);
  color:#a9b8bd;display:flex;align-items:center;justify-content:space-between;gap:36px;flex-wrap:wrap;
}
.cta-band h2{color:#fff;font-size:clamp(1.4rem,2.4vw,1.95rem);margin-bottom:10px}
.cta-band p{font-size:14.5px;color:#98a9ae;max-width:36em}
.cta-actions{display:flex;gap:12px;flex-wrap:wrap}

/* ---------- 页头（内页） ---------- */
.page-hero{
  background:
    radial-gradient(700px 340px at 92% -20%,rgba(212,98,42,.16),transparent 60%),
    radial-gradient(700px 380px at 0% 120%,rgba(13,124,130,.26),transparent 62%),
    var(--dark);
  color:#a3b2b7;padding:64px 0 56px;
}
.page-hero h1{color:#fff;font-size:clamp(1.9rem,3.6vw,2.9rem);margin:16px 0 14px}
.page-hero p{font-size:16px;max-width:44em;color:#9fb0b5}
.crumbs{font-size:12.5px;color:#7d9095;display:flex;gap:8px;align-items:center;margin-top:26px}
.crumbs a:hover{color:#cfe0e0}

/* ---------- 关于我们 ---------- */
.prose{max-width:74ch}
.prose p{font-size:16px;color:var(--body);margin-bottom:18px}
.prose p:last-child{margin-bottom:0}
.prose strong{color:var(--ink);font-weight:600}

.timeline{position:relative;padding-left:28px}
.timeline::before{content:"";position:absolute;left:5px;top:6px;bottom:6px;width:1px;background:var(--line)}
.tl-item{position:relative;padding:0 0 30px 0}
.tl-item:last-child{padding-bottom:0}
.tl-item::before{
  content:"";position:absolute;left:-28px;top:7px;width:11px;height:11px;border-radius:50%;
  background:var(--paper);border:2px solid var(--teal);
}
.tl-item b{display:block;font-size:12.5px;letter-spacing:.1em;color:var(--teal);margin-bottom:4px}
.tl-item h3{font-size:16.5px;margin-bottom:6px}
.tl-item p{font-size:14px;color:var(--muted)}

.value-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:18px}
.value{background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);padding:26px 22px}
.value b{display:block;font-size:15.5px;color:var(--ink);margin-bottom:8px}
.value p{font-size:13.5px;color:var(--muted)}

/* ---------- 联系 ---------- */
.contact-grid{display:grid;grid-template-columns:.95fr 1.05fr;gap:34px;align-items:start}
.info-card{background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);padding:8px 24px}
.info-row{display:flex;gap:16px;padding:20px 0;border-bottom:1px solid var(--line)}
.info-row:last-child{border-bottom:0}
.info-row svg{width:19px;height:19px;color:var(--teal);flex:none;margin-top:3px}
.info-row b{display:block;font-size:13px;color:var(--muted);font-weight:500;margin-bottom:3px}
.info-row span{font-size:15px;color:var(--ink);font-weight:500;line-height:1.6}
.info-row em{font-style:normal;color:var(--ember);font-size:12.5px}

.form-card{background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);padding:30px}
.form-card h2{font-size:19px;margin-bottom:6px}
.form-card .hint{font-size:13px;color:var(--muted);margin-bottom:22px}
.field{margin-bottom:16px}
.field label{display:block;font-size:13px;color:var(--ink-soft);font-weight:500;margin-bottom:6px}
.field input,.field textarea,.field select{
  width:100%;padding:11px 13px;border:1px solid var(--line);border-radius:9px;
  font-family:inherit;font-size:14.5px;color:var(--ink);background:var(--paper-2);
  transition:border-color .2s,background .2s;
}
.field textarea{min-height:118px;resize:vertical}
.field input:focus,.field textarea:focus,.field select:focus{
  outline:none;border-color:var(--teal);background:#fff;box-shadow:0 0 0 3px rgba(13,124,130,.1);
}
.field-row{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.form-note{font-size:12px;color:var(--muted);margin-top:14px;line-height:1.7}

/* ---------- 页脚 ---------- */
.site-footer{background:var(--dark-2);color:#93a4aa;padding:60px 0 0;font-size:14px}
.footer-grid{display:grid;grid-template-columns:1.5fr .9fr .9fr 1.1fr;gap:34px;padding-bottom:44px}
.footer-brand .brand{color:#fff}
.footer-brand .brand-mark{color:#7fd2cd}
.footer-brand .brand-text small{color:#7d9095}
.footer-brand p{margin-top:16px;font-size:13px;color:#8ba0a5;line-height:1.8;max-width:30em}
.footer-col h3{color:#dfeaea;font-size:13px;letter-spacing:.1em;margin-bottom:16px;font-weight:600}
.footer-col a,.footer-col span{display:block;color:#93a4aa;font-size:13.5px;padding:5px 0;transition:color .2s}
.footer-col a:hover{color:#7fd2cd}
.footer-bottom{
  border-top:1px solid rgba(255,255,255,.08);
  padding:20px 0 26px;display:flex;justify-content:space-between;gap:14px;flex-wrap:wrap;
  font-size:12.5px;color:#7d9095;
}
.footer-bottom a:hover{color:#7fd2cd}

/* ---------- 动效 ---------- */
.reveal{opacity:0;transform:translateY(18px);transition:opacity .7s var(--ease),transform .7s var(--ease)}
.reveal.in{opacity:1;transform:none}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal{opacity:1;transform:none;transition:none}
  *{animation-duration:.01ms !important;transition-duration:.01ms !important}
}

/* ---------- 响应式 ---------- */
@media (max-width:1024px){
  .hero-inner{grid-template-columns:1fr;gap:42px}
  .hero{padding:64px 0 58px}
  .feature{grid-template-columns:1fr}
  .feature-side{border-left:0;border-top:1px solid rgba(255,255,255,.08)}
  .grid--4{grid-template-columns:repeat(2,1fr)}
  .logo-grid{grid-template-columns:repeat(2,1fr)}
  .value-grid{grid-template-columns:repeat(2,1fr)}
  .footer-grid{grid-template-columns:1fr 1fr}
  .honor{grid-template-columns:1fr}
  .contact-grid{grid-template-columns:1fr}
  .matrix-row{grid-template-columns:44px minmax(0,1.4fr) 120px}
  .matrix-row p{display:none}
}

@media (max-width:820px){
  .nav{
    position:absolute;left:0;right:0;top:72px;
    background:#fff;border-bottom:1px solid var(--line);
    flex-direction:column;align-items:stretch;gap:0;padding:10px 16px 18px;
    box-shadow:0 24px 40px -30px rgba(12,26,32,.6);
    display:none;
  }
  .nav.is-open{display:flex}
  .nav a{padding:13px 10px;font-size:15px;border-radius:8px}
  .nav a.active::after{display:none}
  .header-cta{display:none}
  .nav-toggle{display:flex}
  .section{padding:64px 0}
  .grid--3{grid-template-columns:1fr}
  .grid--2{grid-template-columns:1fr}
  .result-grid{grid-template-columns:1fr}
  .metrics-grid{grid-template-columns:1fr 1fr}
  .metric:nth-child(3){border-left:0}
  .metric{border-top:1px solid var(--line);padding:24px 6px}
  .metric:nth-child(-n+2){border-top:0}
  .cta-band{padding:36px 26px}
  .quote{grid-template-columns:1fr;padding:26px 24px;gap:10px}
  .feature-main,.feature-side{padding:30px 24px}
  .footer-grid{grid-template-columns:1fr;gap:26px}
  .field-row{grid-template-columns:1fr}
  .sys-badge{right:0;top:-14px}
  .matrix-row{grid-template-columns:34px 1fr;row-gap:8px}
  .matrix-row .tag{justify-self:start;grid-column:2}
}

@media (max-width:520px){
  .metrics-grid{grid-template-columns:1fr}
  .metric{border-left:0;border-top:1px solid var(--line)}
  .metric:first-child{border-top:0}
  .logo-grid{grid-template-columns:1fr}
  .value-grid{grid-template-columns:1fr}
  .grid--4{grid-template-columns:1fr}
  .hero h1{font-size:2rem}
  .container{padding:0 18px}
}

/* 打印 */
@media print{
  .site-header,.hero-actions,.cta-band,.site-footer .footer-col,.nav-toggle{display:none}
  body{background:#fff}
  .hero,.page-hero{background:#fff;color:#000}
  .hero h1,.page-hero h1{color:#000}
}