/* ALUFORM design system — extended from the approved demo */
:root{
  --ink:#111317; --muted:#6d727a; --line:#e5e7eb; --paper:#f7f7f5;
  --silver:#d8dadd; --accent:#b98f62; --dark:#17191d;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:Inter,ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI",Arial,sans-serif;color:var(--ink);background:#fff;line-height:1.55}
a{color:inherit;text-decoration:none}
img{display:block;width:100%}
.container{width:min(1180px,calc(100% - 40px));margin:auto}

/* Nav */
.nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.88);backdrop-filter:blur(16px);border-bottom:1px solid rgba(0,0,0,.06)}
.nav-inner{height:72px;display:flex;align-items:center;justify-content:space-between;gap:20px}
.brand{font-weight:800;letter-spacing:.18em;font-size:18px}
.brand span{font-weight:400;color:var(--muted)}
.menu{display:flex;gap:26px;font-size:14px;color:#353940}
.menu a:hover{color:var(--accent)}
.nav-right{display:flex;align-items:center;gap:14px}
.lang-switch{display:flex;gap:2px;font-size:12px;font-weight:700;border:1px solid var(--line);border-radius:999px;padding:3px}
.lang-switch a{padding:4px 9px;border-radius:999px;color:var(--muted)}
.lang-switch a.on{background:var(--ink);color:#fff}
.nav-cta,.btn{display:inline-flex;align-items:center;justify-content:center;border-radius:999px;padding:13px 22px;border:1px solid var(--ink);font-size:14px;font-weight:700;transition:.25s ease;cursor:pointer}
.nav-cta:hover,.btn:hover{transform:translateY(-2px);box-shadow:0 10px 25px rgba(0,0,0,.12)}
.btn.dark{background:var(--ink);color:#fff}
.btn.light{background:#fff;border-color:#fff;color:var(--ink)}
.btn.gold{background:var(--accent);border-color:var(--accent);color:#fff}
.nav-burger{display:none;flex-direction:column;gap:5px;background:none;border:0;padding:8px;cursor:pointer}
.nav-burger span{width:22px;height:2px;background:var(--ink)}
.mobile-menu{display:none;flex-direction:column;border-top:1px solid var(--line)}
.mobile-menu a{padding:15px 22px;border-bottom:1px solid var(--line);font-weight:600}
body.menu-open .mobile-menu{display:flex}

/* Hero：高度跟随屏宽（约 16:7.5，与 1920×900 素材同比例），大屏不放大裁切、小屏自动收窄 */
.hero{height:clamp(540px,47vw,880px);background:linear-gradient(90deg,rgba(12,14,17,.88) 0%,rgba(12,14,17,.6) 42%,rgba(12,14,17,.15) 76%),radial-gradient(1200px 600px at 80% 30%,#3a3f47,#17191d);color:#fff;display:flex;align-items:center}
/* 首屏文字容器更宽 → 文字更靠左 */
.hero .container{width:min(1460px,calc(100% - 48px))}
.hero{position:relative;overflow:hidden}
.hero-video{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}
.hero-slides{position:absolute;inset:0}
.hero-slide{position:absolute;inset:0;background-position:center;background-size:cover;background-repeat:no-repeat;opacity:0;transition:opacity 1.1s ease}
.hero-slide.on{opacity:1}
.hero-overlay{position:absolute;inset:0;background:linear-gradient(90deg,rgba(12,14,17,.88) 0%,rgba(12,14,17,.6) 42%,rgba(12,14,17,.15) 76%)}
.hero-dots{position:absolute;bottom:24px;left:50%;transform:translateX(-50%);display:flex;gap:9px;z-index:3}
.hero-dot{width:10px;height:10px;border-radius:50%;background:rgba(255,255,255,.4);border:0;cursor:pointer;padding:0;transition:.2s}
.hero-dot.on{background:var(--accent);transform:scale(1.2)}
.hero-content{max-width:690px;padding:80px 0;position:relative;z-index:2}
.eyebrow{text-transform:uppercase;letter-spacing:.18em;font-size:12px;font-weight:800;color:var(--accent)}
.hero h1{font-size:clamp(44px,7vw,84px);line-height:.98;letter-spacing:-.05em;margin:18px 0 24px}
.hero p{font-size:20px;color:rgba(255,255,255,.78);max-width:580px;margin-bottom:34px}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap}

/* Stats / sections */
.stats{display:grid;grid-template-columns:repeat(4,1fr);border-bottom:1px solid var(--line)}
.stat{padding:34px 24px;border-right:1px solid var(--line)}
.stat:last-child{border-right:0}
.stat strong{display:block;font-size:28px}
.stat span{font-size:13px;color:var(--muted)}
section{padding:90px 0}
.section-head{display:flex;justify-content:space-between;gap:30px;align-items:end;margin-bottom:42px}
.section-head h2{font-size:clamp(34px,5vw,54px);line-height:1.05;letter-spacing:-.04em;margin:8px 0}
.section-head p{max-width:520px;color:var(--muted);margin:0}

/* Cards */
.products{display:grid;grid-template-columns:1.2fr .8fr .8fr;gap:18px}
.card{position:relative;overflow:hidden;border-radius:26px;background:var(--paper);min-height:420px}
.card img{height:100%;object-fit:cover;transition:.5s ease;position:absolute;inset:0}
.card:hover img{transform:scale(1.04)}
.card .overlay{position:absolute;inset:auto 18px 18px 18px;background:rgba(255,255,255,.92);backdrop-filter:blur(12px);border-radius:18px;padding:18px}
.card h3{margin:0 0 6px;font-size:22px}
.card p{margin:0;color:var(--muted);font-size:14px}
.card.tall{min-height:560px}

/* Product grid (listing) */
.pgrid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.pcard{border:1px solid var(--line);border-radius:22px;overflow:hidden;background:#fff;transition:.25s ease;display:flex;flex-direction:column}
.pcard:hover{transform:translateY(-4px);box-shadow:0 16px 40px rgba(0,0,0,.08)}
.pcard .pimg{aspect-ratio:4/3;background:var(--paper);overflow:hidden}
.pcard .pimg img{height:100%;object-fit:cover}
.pcard .pbody{padding:20px;display:flex;flex-direction:column;gap:8px;flex:1}
.pcard h3{margin:0;font-size:19px;letter-spacing:-.01em}
.pcard p{margin:0;color:var(--muted);font-size:14px;flex:1}
.pcard .cat{font-size:11px;font-weight:800;letter-spacing:.12em;text-transform:uppercase;color:var(--accent)}
.pcard .plink{font-size:14px;font-weight:700}

/* Filter bar */
.filterbar{display:flex;gap:12px;flex-wrap:wrap;align-items:center;margin-bottom:34px}
.filterbar input[type=search]{flex:1;min-width:220px;padding:13px 18px;border:1px solid var(--line);border-radius:999px;font-size:14px;font-family:inherit}
.chip{padding:10px 18px;border:1px solid var(--line);border-radius:999px;font-size:13px;font-weight:600;color:#353940;transition:.2s}
.chip:hover{border-color:var(--ink)}
.chip.on{background:var(--ink);color:#fff;border-color:var(--ink)}

/* Page hero (inner pages) */
.page-hero{background:var(--dark);color:#fff;padding:74px 0 60px}
.page-hero h1{font-size:clamp(36px,5vw,62px);letter-spacing:-.04em;line-height:1.02;margin:14px 0 12px}
.page-hero p{color:rgba(255,255,255,.72);max-width:640px;margin:0;font-size:17px}
.crumbs{font-size:13px;color:rgba(255,255,255,.55)}
.crumbs a:hover{color:#fff}
.crumbs.dark{color:var(--muted)}

/* Product detail */
.pdetail{display:grid;grid-template-columns:1.05fr .95fr;gap:56px;align-items:start}
.pdetail-img{border-radius:26px;overflow:hidden;background:var(--paper);position:sticky;top:96px}
.pdetail h1{font-size:clamp(30px,4vw,46px);letter-spacing:-.03em;line-height:1.05;margin:10px 0 14px}
.pdetail .lead{font-size:17px;color:var(--muted)}
.spec-table{width:100%;border-collapse:collapse;margin:26px 0;font-size:14px}
.spec-table th,.spec-table td{text-align:left;padding:11px 14px;border-bottom:1px solid var(--line)}
.spec-table th{width:38%;color:var(--muted);font-weight:600}
.prose{font-size:16px;line-height:1.75}
.prose h2{font-size:26px;letter-spacing:-.02em;margin:34px 0 12px}
.prose img{border-radius:18px;margin:22px 0}
.prose p{margin:0 0 16px}

/* Industries */
.industries{background:var(--dark);color:#fff}
.industry-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.industry{padding:28px;border:1px solid rgba(255,255,255,.13);border-radius:20px;min-height:180px;display:flex;flex-direction:column;justify-content:space-between;transition:.25s ease}
.industry:hover{background:#fff;color:var(--ink);transform:translateY(-4px)}
.industry .num{font-size:12px;color:var(--accent);font-weight:800}
.industry h3{font-size:24px;margin:28px 0 0}
.industry p{font-size:14px;color:inherit;opacity:.65;margin:10px 0 0}

/* Custom / features */
.custom{display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:center}
.custom-visual{border-radius:30px;overflow:hidden;background:#ececeb;min-height:480px}
.custom-visual img{height:100%;min-height:480px;object-fit:cover}
.custom h2{font-size:clamp(34px,5vw,58px);line-height:1.02;letter-spacing:-.04em;margin:12px 0 22px}
.feature-list{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin:32px 0}
.feature{padding:18px;border:1px solid var(--line);border-radius:16px}
.feature b{display:block;margin-bottom:4px}
.feature small{color:var(--muted)}

/* Process */
.process{background:var(--paper)}
.steps{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.step{background:#fff;border-radius:20px;padding:26px;border:1px solid var(--line)}
.step span{font-size:12px;letter-spacing:.12em;color:var(--accent);font-weight:800}
.step h3{font-size:20px;margin:18px 0 8px}
.step p{color:var(--muted);font-size:14px;margin:0}

/* News */
.news-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.ncard{border:1px solid var(--line);border-radius:22px;overflow:hidden;background:#fff;transition:.25s}
.ncard:hover{transform:translateY(-4px);box-shadow:0 16px 40px rgba(0,0,0,.08)}
.ncard .nimg{aspect-ratio:16/9;background:var(--paper);overflow:hidden}
.ncard .nimg img{height:100%;object-fit:cover}
.ncard .nbody{padding:20px}
.ncard time{font-size:12px;color:var(--muted);font-weight:600;letter-spacing:.06em;text-transform:uppercase}
.ncard h3{font-size:19px;margin:8px 0;letter-spacing:-.01em;line-height:1.3}
.ncard p{font-size:14px;color:var(--muted);margin:0}
.article{max-width:760px;margin:auto}
.article h1{font-size:clamp(32px,4.5vw,52px);letter-spacing:-.03em;line-height:1.06}
.article .meta{color:var(--muted);font-size:14px;margin-bottom:30px}

/* Forms */
.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.form-grid .full{grid-column:1/-1}
.input,textarea.input,select.input{width:100%;padding:14px 16px;border:1px solid var(--line);border-radius:14px;font-size:15px;font-family:inherit;background:#fff}
.input:focus{outline:2px solid var(--accent);border-color:transparent}
label.lb{display:block;font-size:13px;font-weight:700;margin-bottom:6px}
.alert{padding:16px 20px;border-radius:14px;margin-bottom:20px;font-size:15px}
.alert.ok{background:#eefaf0;border:1px solid #b7e4c0;color:#19632b}
.alert.err{background:#fdf0ef;border:1px solid #f2c4c0;color:#8c2b23}

/* CTA / misc */
.cta{margin:90px auto;border-radius:32px;padding:56px;background:linear-gradient(135deg,#c4c6c9,#f1f1ef 50%,#b8babd);display:flex;justify-content:space-between;align-items:center;gap:30px}
.cta h2{font-size:clamp(30px,5vw,52px);line-height:1.04;letter-spacing:-.04em;margin:0;max-width:700px}
.cert-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.cert{border:1px solid var(--line);border-radius:18px;padding:24px;text-align:center}
.cert b{display:block;font-size:18px;margin-bottom:6px}
.cert small{color:var(--muted)}
.pagination{display:flex;gap:8px;justify-content:center;margin-top:44px}
.pagination a,.pagination span{padding:9px 16px;border:1px solid var(--line);border-radius:12px;font-size:14px;font-weight:600}
.pagination .cur{background:var(--ink);color:#fff;border-color:var(--ink)}

/* Footer */
footer{background:#101216;color:#fff;padding:60px 0 28px}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:40px}
footer p,footer a{color:rgba(255,255,255,.64);font-size:14px}
footer a:hover{color:#fff}
.copyright{border-top:1px solid rgba(255,255,255,.12);margin-top:40px;padding-top:22px;color:rgba(255,255,255,.45);font-size:13px}
.copyright a{color:rgba(255,255,255,.45)}

/* WhatsApp float */
.wa-float{position:fixed;right:22px;bottom:22px;z-index:60;width:56px;height:56px;border-radius:50%;background:#25d366;display:flex;align-items:center;justify-content:center;box-shadow:0 8px 24px rgba(0,0,0,.25);transition:.25s}
.wa-float:hover{transform:scale(1.08)}

/* Responsive */
@media(max-width:900px){
  .menu,.lang-switch{display:none}
  .nav-burger{display:flex}
  .stats{grid-template-columns:1fr 1fr}
  .stat:nth-child(2){border-right:0}
  .products,.pgrid,.news-grid{grid-template-columns:1fr 1fr}
  .products .card:first-child{grid-column:1/-1}
  .industry-grid{grid-template-columns:1fr 1fr}
  .custom,.pdetail{grid-template-columns:1fr}
  .pdetail-img{position:static}
  .steps{grid-template-columns:1fr 1fr}
  .cert-grid{grid-template-columns:1fr 1fr}
  .cta{padding:42px;align-items:flex-start;flex-direction:column}
}
@media(max-width:620px){
  .container{width:min(100% - 24px,1180px)}
  .nav-inner{height:64px}
  .nav-cta{padding:10px 14px}
  .hero{height:auto;min-height:560px}
  .hero p{font-size:17px}
  section{padding:66px 0}
  .stats,.products,.pgrid,.news-grid,.industry-grid,.steps,.feature-list,.footer-grid,.form-grid{grid-template-columns:1fr}
  .stat{border-right:0;border-bottom:1px solid var(--line)}
  .products .card:first-child{grid-column:auto}
  .card,.card.tall{min-height:400px}
  .section-head{display:block}
  .custom-visual,.custom-visual img{min-height:380px}
  .cta{margin:60px auto;padding:32px 24px}
}