/* ============================================================
   中铜科技 v2 · 主样式（深炭黑 × 铜金工业风）
   ============================================================ */
:root{
  --ink:#16171b; --ink2:#1e2026; --ink3:#262932;
  --paper:#f7f7f5; --card:#ffffff;
  --gold:#b0703a; --gold2:#c98a4b; --gold-soft:#8a5a2b;
  --txt:#2a2b30; --mut:#6a6d76; --line:#e4e2dc;
  --dark-txt:#eae7e0; --dark-mut:#a9a7a0;
  --radius:10px; --shadow:0 6px 24px rgba(20,20,25,.08);
  --font:"PingFang SC","Microsoft YaHei","Noto Sans SC",-apple-system,"Segoe UI",Roboto,Arial,sans-serif;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:var(--font);color:var(--txt);background:var(--paper);line-height:1.65;-webkit-font-smoothing:antialiased}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
.container{max-width:1200px;margin:0 auto;padding:0 20px}
.gold{color:var(--gold2)}

/* ---------- Header ---------- */
.site-header{background:var(--ink);color:#fff;position:sticky;top:0;z-index:100;box-shadow:0 2px 12px rgba(0,0,0,.25)}
.header-inner{display:flex;align-items:center;gap:24px;height:72px}
.brand{display:flex;align-items:center;gap:12px;min-width:0}
.brand img{height:44px;width:44px;object-fit:cover;border-radius:8px}
.brand-text{display:flex;flex-direction:column;line-height:1.25;min-width:0}
.brand-text b{font-size:17px;letter-spacing:.5px;white-space:nowrap}
.brand-text small{font-size:11px;color:var(--dark-mut);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.main-nav{display:flex;gap:4px;margin-left:auto}
.main-nav a{padding:8px 14px;font-size:14.5px;color:#cfcdc6;border-radius:8px;transition:.2s}
.main-nav a:hover{color:#fff;background:rgba(255,255,255,.08)}
.main-nav a.on{color:#fff;background:linear-gradient(135deg,var(--gold),var(--gold2))}
.lang-switch{display:flex;align-items:center;gap:6px;border:1px solid rgba(255,255,255,.25);border-radius:20px;padding:4px 12px}
.lang-switch a{font-size:13px;color:#cfcdc6;font-weight:600}
.lang-switch a.on{color:var(--gold2)}
.lang-sep{color:rgba(255,255,255,.3)}
.nav-toggle{display:none;background:none;border:0;cursor:pointer;padding:8px;margin-left:auto}
.nav-toggle span{display:block;width:22px;height:2px;background:#fff;margin:5px 0;border-radius:2px}

/* ---------- Buttons ---------- */
.btn-main{display:inline-block;background:linear-gradient(135deg,var(--gold),var(--gold2));color:#fff;padding:13px 30px;border-radius:30px;font-weight:600;font-size:15px;transition:.25s;box-shadow:0 4px 16px rgba(176,112,58,.35)}
.btn-main:hover{transform:translateY(-2px);box-shadow:0 8px 22px rgba(176,112,58,.45)}
.btn-main.btn-lg{padding:16px 44px;font-size:16px}
.btn-ghost{display:inline-block;border:1.5px solid rgba(255,255,255,.6);color:#fff;padding:12px 28px;border-radius:30px;font-weight:600;font-size:15px;transition:.25s}
.btn-ghost:hover{background:rgba(255,255,255,.12);border-color:#fff}

/* ---------- Hero ---------- */
.hero{background-size:cover;background-position:center;color:#fff;padding:110px 0 90px}
.hero-inner{max-width:820px}
.hero-badge{display:inline-block;border:1px solid rgba(201,138,75,.6);color:var(--gold2);border-radius:30px;padding:6px 16px;font-size:13px;margin-bottom:22px;letter-spacing:1px}
.hero h1{font-size:clamp(32px,5vw,54px);line-height:1.18;margin-bottom:20px;font-weight:800;letter-spacing:.5px}
.hero h1 .gold{display:block;margin-top:6px;background:linear-gradient(90deg,var(--gold2),#e8b97c);-webkit-background-clip:text;background-clip:text;color:transparent}
.hero-sub{font-size:17px;color:rgba(255,255,255,.85);max-width:640px;margin-bottom:34px}
.hero-actions{display:flex;gap:16px;flex-wrap:wrap}
.hero-meta{display:flex;gap:26px;margin-top:44px;flex-wrap:wrap;font-size:13.5px;color:rgba(255,255,255,.75)}
.hero-meta span{display:flex;align-items:center;gap:8px}

/* ---------- Stats ---------- */
.stats-band{background:var(--ink2);color:#fff}
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;padding:38px 20px}
.stat{text-align:center}
.stat .num{font-size:clamp(28px,4vw,42px);font-weight:800;color:var(--gold2);line-height:1.1}
.stat .lbl{font-size:14px;color:var(--dark-mut);margin-top:6px}

/* ---------- Sections ---------- */
.section{padding:76px 0}
.section-alt{background:var(--card)}
.section-dark{background:var(--ink);color:var(--dark-txt)}
.sec-head{text-align:center;margin-bottom:46px}
.sec-head .eyebrow{display:inline-block;color:var(--gold);font-size:12.5px;font-weight:700;letter-spacing:3px;text-transform:uppercase;margin-bottom:10px}
.sec-head h2{font-size:clamp(24px,3.2vw,34px);font-weight:800;color:var(--ink)}
.sec-head p{color:var(--mut);margin-top:10px;font-size:15.5px}
.sec-head.light h2{color:#fff}
.sec-head.light p{color:var(--dark-mut)}

/* ---------- Product grid ---------- */
.prod-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.prod-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;transition:.28s;display:flex;flex-direction:column}
.prod-card:hover{transform:translateY(-6px);box-shadow:var(--shadow);border-color:var(--gold2)}
.prod-pic{aspect-ratio:4/3;overflow:hidden;background:#e9e7e1}
.prod-pic img{width:100%;height:100%;object-fit:cover;transition:.4s}
.prod-card:hover .prod-pic img{transform:scale(1.05)}
.prod-info{padding:20px;display:flex;flex-direction:column;gap:8px;flex:1}
.prod-info h3{font-size:17px;font-weight:700;color:var(--ink)}
.prod-info p{font-size:13.5px;color:var(--mut);flex:1}
.go{color:var(--gold);font-weight:600;font-size:13.5px}
.prod-grid-3{grid-template-columns:repeat(3,1fr)}

/* ---------- Spec grid ---------- */
.spec-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.spec-item{background:var(--ink3);border:1px solid rgba(255,255,255,.08);border-radius:var(--radius);padding:22px;transition:.25s}
.spec-item:hover{border-color:var(--gold2)}
.spec-item b{display:block;color:var(--gold2);font-size:16.5px;margin-bottom:6px}
.spec-item span{font-size:13.5px;color:var(--dark-mut)}

/* ---------- Features ---------- */
.feat-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.feat-item{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:26px;transition:.25s}
.feat-item:hover{box-shadow:var(--shadow);border-color:var(--gold2)}
.feat-ico{width:40px;height:4px;background:linear-gradient(90deg,var(--gold),var(--gold2));border-radius:2px;margin-bottom:16px}
.feat-item h3{font-size:17px;color:var(--ink);margin-bottom:8px}
.feat-item p{font-size:13.5px;color:var(--mut)}

/* ---------- Image grids ---------- */
.img-grid{display:grid;gap:16px}
.img-grid-4{grid-template-columns:repeat(4,1fr)}
.img-grid-3{grid-template-columns:repeat(3,1fr)}
.img-grid figure{background:#eee;border-radius:var(--radius);overflow:hidden;aspect-ratio:4/3;border:1px solid var(--line)}
.img-grid img{width:100%;height:100%;object-fit:cover;transition:.4s}
.img-grid figure:hover img{transform:scale(1.04)}

/* ---------- CTA band ---------- */
.cta-band{background:linear-gradient(135deg,var(--ink) 0%,var(--ink3) 60%,#3a2c1c 100%);color:#fff;text-align:center;padding:80px 20px}
.cta-band h2{font-size:clamp(24px,3.2vw,34px);font-weight:800;margin-bottom:14px}
.cta-band p{color:var(--dark-mut);max-width:560px;margin:0 auto 30px}

/* ---------- Page hero ---------- */
.page-hero{background:var(--ink);color:#fff;padding:64px 0 56px}
.page-hero-sm{padding:26px 0}
.page-hero h1{font-size:clamp(26px,3.4vw,38px);font-weight:800}
.page-hero p{color:var(--dark-mut);margin-top:8px;font-size:15.5px}

/* ---------- Breadcrumb ---------- */
.crumbs{font-size:13.5px;color:var(--mut);margin-bottom:26px;display:flex;flex-wrap:wrap;gap:6px;align-items:center}
.crumbs a:hover{color:var(--gold)}
.crumbs .cur{color:var(--gold)}
.crumbs .sep{color:#b9b6ae}

/* ---------- Product page ---------- */
.product-layout{display:grid;grid-template-columns:1fr 1.15fr;gap:44px;align-items:start}
.product-gallery .pg-main{border-radius:var(--radius);overflow:hidden;border:1px solid var(--line);background:#fff}
.product-gallery .pg-main img{width:100%;aspect-ratio:4/3;object-fit:cover}
.pg-thumbs{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin-top:10px}
.pg-thumbs img{aspect-ratio:4/3;object-fit:cover;border-radius:8px;cursor:pointer;border:2px solid transparent;transition:.2s}
.pg-thumbs img:hover{border-color:var(--gold2)}
.product-main h1{font-size:clamp(24px,3vw,32px);font-weight:800;color:var(--ink);line-height:1.3;margin-bottom:10px}
.p-short{color:var(--gold);font-weight:600;margin-bottom:14px}
.p-desc{color:var(--mut);font-size:15px;margin-bottom:24px}
.p-actions{display:flex;gap:14px;flex-wrap:wrap}

/* ---------- Spec table ---------- */
.spec-table{width:100%;border-collapse:collapse;background:var(--card);border-radius:var(--radius);overflow:hidden;border:1px solid var(--line)}
.spec-table th{background:var(--ink2);color:#fff;text-align:left;padding:13px 18px;font-size:14px;width:200px;font-weight:600}
.spec-table td{padding:13px 18px;font-size:14px;border-top:1px solid var(--line)}
.spec-table tr:nth-child(even) td{background:#fafaf8}

/* ---------- FAQ ---------- */
.faq-list{max-width:860px;margin:0 auto;display:flex;flex-direction:column;gap:12px}
.faq-item{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:0 20px;transition:.2s}
.faq-item[open]{border-color:var(--gold2);box-shadow:var(--shadow)}
.faq-item summary{cursor:pointer;font-weight:600;font-size:15.5px;color:var(--ink);padding:16px 0;list-style:none;display:flex;align-items:center;gap:12px}
.faq-item summary::before{content:"+";color:var(--gold);font-weight:800;font-size:18px}
.faq-item[open] summary::before{content:"–"}
.faq-item p{padding:0 0 18px;color:var(--mut);font-size:14.5px}
.faq-more{text-align:center;margin-top:40px}
.faq-more p{color:var(--mut);margin-bottom:14px}

/* ---------- Articles ---------- */
.article-list{display:flex;flex-direction:column;gap:18px;max-width:900px;margin:0 auto}
.article-item{display:flex;gap:20px;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:18px;transition:.25s}
.article-item:hover{box-shadow:var(--shadow);border-color:var(--gold2);transform:translateY(-3px)}
.ai-pic{width:190px;flex-shrink:0;border-radius:8px;overflow:hidden;background:#eee}
.ai-pic img{width:100%;height:100%;object-fit:cover;aspect-ratio:4/3}
.ai-body{display:flex;flex-direction:column;gap:6px}
.ai-body time{font-size:12.5px;color:var(--mut)}
.ai-body h3{font-size:17.5px;color:var(--ink)}
.ai-body p{font-size:14px;color:var(--mut);flex:1}
.article-body{max-width:820px;margin:0 auto}
.article-body h1{font-size:clamp(24px,3.2vw,34px);color:var(--ink);line-height:1.35;margin-bottom:8px}
.a-date{color:var(--mut);font-size:13.5px}
.article-body p{margin-top:20px;font-size:15.5px;color:#3d3e44;line-height:1.9}
.a-cta{margin-top:44px;background:var(--ink);color:#fff;border-radius:var(--radius);padding:34px;text-align:center}
.a-cta p{color:var(--dark-mut);margin:0 0 18px;font-size:16px}
.empty{text-align:center;color:var(--mut);padding:60px 0}
.search-count{color:var(--mut);margin-bottom:20px}
.search-form{display:flex;gap:10px;margin-top:18px;max-width:520px}
.search-form input{flex:1;padding:12px 18px;border:1px solid rgba(255,255,255,.3);border-radius:30px;background:rgba(255,255,255,.08);color:#fff;font-size:14.5px;outline:none}
.search-form input::placeholder{color:var(--dark-mut)}

/* ---------- About ---------- */
.about-layout{display:grid;grid-template-columns:1.6fr 1fr;gap:44px;align-items:start}
.about-text h2{font-size:24px;color:var(--ink);margin-bottom:18px}
.about-text p{margin-bottom:16px;font-size:15px;color:#3d3e44;line-height:1.9}
.about-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:26px}
.about-card h3{font-size:17px;color:var(--ink);margin-bottom:16px;padding-bottom:12px;border-bottom:2px solid var(--gold)}
.about-card ul{list-style:none}
.about-card li{display:flex;justify-content:space-between;gap:16px;padding:9px 0;border-bottom:1px dashed var(--line);font-size:14px}
.about-card li b{color:var(--ink)}
.about-card li span{color:var(--mut);text-align:right}
.timeline{max-width:760px;margin:0 auto;position:relative;padding-left:26px}
.timeline::before{content:"";position:absolute;left:6px;top:6px;bottom:6px;width:2px;background:linear-gradient(var(--gold),var(--gold2))}
.tl-item{position:relative;padding:14px 0 14px 26px}
.tl-item::before{content:"";position:absolute;left:-24px;top:22px;width:12px;height:12px;border-radius:50%;background:var(--gold2);border:3px solid var(--ink)}
.tl-item b{display:block;color:var(--gold2);font-size:17px}
.tl-item span{color:var(--dark-mut);font-size:14px}

/* ---------- Contact ---------- */
.contact-layout{display:grid;grid-template-columns:1fr 1.1fr;gap:44px;align-items:start}
.contact-info h2,.contact-form h2{font-size:22px;color:var(--ink);margin:16px 0 18px}
.c-list{list-style:none;display:flex;flex-direction:column;gap:14px}
.c-list li{display:flex;flex-direction:column;gap:2px;padding-bottom:12px;border-bottom:1px dashed var(--line)}
.c-list b{font-size:12.5px;color:var(--gold);letter-spacing:1px}
.c-list a,.c-list span{font-size:15.5px;color:var(--ink);font-weight:600}
.c-tip{background:var(--card);border:1px solid var(--line);border-left:4px solid var(--gold);border-radius:8px;padding:18px;margin-top:24px}
.c-tip h3{font-size:15px;color:var(--ink);margin-bottom:6px}
.c-tip p{font-size:13.5px;color:var(--mut)}
.contact-form form{display:flex;flex-direction:column;gap:4px;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:28px}
.contact-form label{font-size:13.5px;font-weight:600;color:var(--ink);margin-top:12px}
.contact-form label:first-child{margin-top:0}
.contact-form input,.contact-form textarea{padding:11px 14px;border:1.5px solid var(--line);border-radius:8px;font-size:14.5px;font-family:inherit;margin-top:6px;outline:none;transition:.2s;background:#fbfbf9}
.contact-form input:focus,.contact-form textarea:focus{border-color:var(--gold2)}
.contact-form .btn-main{margin-top:20px;border:0;cursor:pointer}
.form-note{margin-top:10px;font-size:13px;color:var(--gold)}

/* ---------- Footer ---------- */
.site-footer{background:var(--ink);color:var(--dark-mut);padding:56px 0 0}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1.2fr 1.4fr;gap:36px;padding-bottom:40px}
.f-col h4{color:#fff;font-size:15.5px;margin-bottom:16px;position:relative;padding-bottom:10px}
.f-col h4::after{content:"";position:absolute;left:0;bottom:0;width:28px;height:2px;background:var(--gold2)}
.f-col a{display:block;padding:4px 0;font-size:13.5px;transition:.2s}
.f-col a:hover{color:var(--gold2)}
.f-motto{color:#fff;font-weight:600;margin-bottom:6px}
.f-slogan{font-size:13px}
.f-contact p{font-size:13.5px;margin-bottom:8px}
.f-contact a:hover{color:var(--gold2)}
.f-bottom{display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;border-top:1px solid rgba(255,255,255,.1);padding:18px 20px;font-size:12.5px}

/* ---------- 404 ---------- */
.nf{text-align:center;padding:120px 20px}
.nf h1{font-size:96px;font-weight:800;background:linear-gradient(135deg,var(--gold),var(--gold2));-webkit-background-clip:text;background-clip:text;color:transparent}
.nf p{color:var(--mut);margin-bottom:26px}

/* ---------- Responsive ---------- */
@media (max-width:1024px){
  .prod-grid,.feat-grid,.spec-grid{grid-template-columns:repeat(2,1fr)}
  .img-grid-4{grid-template-columns:repeat(2,1fr)}
  .footer-grid{grid-template-columns:1fr 1fr}
  .product-layout,.contact-layout,.about-layout{grid-template-columns:1fr}
}
@media (max-width:768px){
  .nav-toggle{display:block}
  .main-nav{display:none;position:absolute;top:72px;left:0;right:0;background:var(--ink2);flex-direction:column;padding:12px 20px 20px;gap:2px;box-shadow:0 10px 24px rgba(0,0,0,.35)}
  .main-nav.open{display:flex}
  .main-nav a{padding:12px 10px}
  .stats-grid{grid-template-columns:repeat(2,1fr);gap:26px}
  .prod-grid,.feat-grid,.spec-grid,.img-grid-3{grid-template-columns:1fr}
  .hero{padding:76px 0 60px}
  .article-item{flex-direction:column}
  .ai-pic{width:100%}
  .ai-pic img{aspect-ratio:16/9}
  .hero-meta{gap:14px}
  .brand-text small{display:none}
}

/* ---------- 富文本正文 ---------- */
.a-content{margin-top:10px}
.a-content p{margin-top:18px;font-size:15.5px;color:#3d3e44;line-height:1.9}
.a-content h2{font-size:22px;color:var(--ink);margin-top:30px}
.a-content h3{font-size:18px;color:var(--ink);margin-top:24px}
.a-content ul,.a-content ol{margin:16px 0 0 22px;font-size:15.5px;color:#3d3e44;line-height:1.9}
.a-content li{margin:6px 0}
.a-content blockquote{border-left:4px solid var(--gold);padding:10px 18px;margin:18px 0;background:var(--card);color:var(--mut)}
.a-content img{border-radius:10px;margin:18px 0}
.a-content a{color:var(--gold);text-decoration:underline}

/* ---------- WhatsApp 悬浮 ---------- */
.wa-float{position:fixed;right:22px;bottom:26px;z-index:999;display:flex;align-items:center;gap:8px;background:#25d366;color:#fff;padding:12px 20px;border-radius:40px;box-shadow:0 6px 22px rgba(37,211,102,.4);font-size:14px;font-weight:600;transition:.25s;text-decoration:none}
.wa-float:hover{transform:translateY(-3px);box-shadow:0 10px 28px rgba(37,211,102,.5)}
.wa-float span{line-height:1}
/* ---------- 页底转化 CTA ---------- */
.cta-strip{background:linear-gradient(135deg,var(--ink),var(--ink3));color:#fff;text-align:center;padding:44px 20px;margin-top:10px}
.cta-strip h3{font-size:clamp(20px,2.6vw,28px);font-weight:800;margin-bottom:10px}
.cta-strip p{color:var(--dark-mut);margin-bottom:22px;font-size:15px}
@media (max-width:768px){.wa-float{padding:11px 15px}.wa-float span{display:none}}

/* ---------- 二维码区 ---------- */
.qr-section{margin-top:28px}
.qr-section h3{font-size:15.5px;color:var(--ink);margin-bottom:14px}
.qr-grid{display:flex;gap:18px;flex-wrap:wrap}
.qr-card{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:16px;text-align:center;width:200px;transition:.25s}
.qr-card:hover{box-shadow:var(--shadow);border-color:var(--gold2)}
.qr-card img{width:100%;border-radius:8px}
.qr-card b{display:block;margin-top:10px;font-size:14.5px;color:var(--ink)}
.qr-card span{font-size:12px;color:var(--mut)}

#qr-section{scroll-margin-top:90px}