:root{
  --brand:#0f6fde; --brand2:#0a4ea8; --accent:#12b9a0;
  --dark:#0f1e33; --ink:#233143; --muted:#6b7a8f;
  --bg:#f6f9fd; --line:#e3eaf3; --white:#fff;
  --shadow:0 10px 30px rgba(15,46,84,.08);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:-apple-system,"PingFang SC","Microsoft YaHei","Noto Sans SC",sans-serif;color:var(--ink);line-height:1.7;background:#fff}
a{color:var(--brand);text-decoration:none}
img{max-width:100%;display:block}
.wrap{max-width:1180px;margin:0 auto;padding:0 22px}
.section{padding:84px 0}
.section-alt{background:var(--bg)}

/* nav */
header{position:fixed;top:0;left:0;right:0;z-index:1000;background:rgba(255,255,255,.92);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.nav-inner{max-width:1180px;margin:0 auto;padding:14px 22px;display:flex;align-items:center;justify-content:space-between}
.logo{display:flex;align-items:center;gap:10px;color:var(--dark)}
.logo-mark{width:38px;height:38px;border-radius:10px;background:linear-gradient(135deg,var(--brand),var(--accent));color:#fff;font-weight:800;display:grid;place-items:center;font-size:20px}
.logo-text{font-weight:800;font-size:18px;letter-spacing:.5px;display:flex;flex-direction:column;line-height:1.1}
.logo-sub{font-size:10px;color:var(--muted);font-weight:600;letter-spacing:1px}
.nav-links{display:flex;gap:28px;align-items:center}
.nav-links a{color:var(--ink);font-weight:600;position:relative}
.nav-links a:hover{color:var(--brand)}
.nav-toggle{display:none;background:none;border:none;font-size:26px;cursor:pointer;color:var(--dark)}

/* hero */
.hero{min-height:92vh;display:flex;align-items:center;color:#fff;position:relative;background:linear-gradient(90deg,rgba(4,12,24,.92) 0%,rgba(4,12,24,.74) 48%,rgba(4,12,24,.38) 100%),linear-gradient(180deg,rgba(4,12,24,0) 38%,rgba(4,12,24,.82) 100%),url('../img/hero-pipe.jpg') center/cover no-repeat;overflow:hidden}
.hero-overlay{position:absolute;inset:0;background:radial-gradient(circle at 80% 20%,rgba(18,185,160,.25),transparent 45%),radial-gradient(circle at 10% 90%,rgba(15,111,222,.3),transparent 40%)}
.hero-inner{position:relative;z-index:2;max-width:1180px;margin:0 auto;padding:120px 22px 60px;width:100%}
.hero-tag{display:inline-block;padding:6px 16px;border:1px solid rgba(255,255,255,.35);border-radius:30px;font-size:14px;letter-spacing:1px;margin-bottom:22px;color:#cfe3ff}
.hero h1{font-size:52px;font-weight:800;letter-spacing:1px;margin-bottom:18px;line-height:1.15}
.hero-desc{font-size:20px;color:#d3e3fb;margin-bottom:34px}
.hero-actions{display:flex;gap:16px;flex-wrap:wrap;margin-bottom:46px}
.btn{padding:13px 30px;border-radius:8px;font-weight:700;font-size:15px;transition:.2s;display:inline-block;border:2px solid transparent}
.btn-primary{background:linear-gradient(135deg,var(--brand),var(--brand2));color:#fff}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 10px 25px rgba(15,111,222,.4)}
.btn-outline{border-color:rgba(255,255,255,.6);color:#fff}
.btn-outline:hover{background:rgba(255,255,255,.12)}
.btn-block{width:100%}
.hero-stats{display:flex;gap:44px;flex-wrap:wrap;list-style:none}
.hero-stats li{text-align:center}
.hero-stats span{font-size:30px;font-weight:800;color:#fff;display:block}
.hero-stats li{color:#a9c4e8;font-size:14px}

/* titles */
.sec-title{text-align:center;font-size:34px;font-weight:800;margin-bottom:8px;color:var(--dark)}
.sec-title span{position:relative;display:inline-block}
.sec-title span::after{content:"";position:absolute;left:50%;transform:translateX(-50%);bottom:-12px;width:56px;height:4px;border-radius:4px;background:linear-gradient(90deg,var(--brand),var(--accent))}
.sec-lead{text-align:center;color:var(--muted);max-width:660px;margin:22px auto 44px;font-size:17px}

/* about */
.about-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:22px}
.about-card{background:#fff;border:1px solid var(--line);border-radius:14px;padding:28px 24px;box-shadow:var(--shadow)}
.about-icon{font-size:34px;margin-bottom:14px}
.about-card h3{font-size:19px;margin-bottom:8px;color:var(--dark)}
.about-card p{color:var(--muted);font-size:15px}
.ci-item a{color:var(--brand);font-weight:600;text-decoration:none}
.ci-item a:hover{text-decoration:underline}
.qr-inline{width:118px;height:118px;display:block;margin:4px 0 8px;border:1px solid var(--line);border-radius:8px}
.crumb{max-width:1180px;margin:0 auto;padding:96px 22px 0;font-size:14px;color:var(--muted)}
.crumb a{color:var(--brand);text-decoration:none}
.crumb span{margin:0 8px;color:#b9c6d6}
.pdetail{display:grid;grid-template-columns:1.05fr 1fr;gap:38px;align-items:start}
.pdetail-media img{width:100%;border-radius:14px;border:1px solid var(--line);display:block;box-shadow:var(--shadow)}
.pdetail-media figcaption{margin-top:10px;font-size:13px;color:var(--muted);text-align:center}
.pdetail h1{font-size:34px;line-height:1.25;margin:0 0 6px;color:var(--dark)}
.pdetail .psub{color:var(--brand);font-weight:700;font-size:15px;margin:0 0 16px}
.pdetail ul.points{list-style:none;padding:0;margin:0 0 22px}
.pdetail ul.points li{padding:9px 0 9px 26px;position:relative;border-bottom:1px dashed var(--line);font-size:15px}
.pdetail ul.points li::before{content:"✓";position:absolute;left:0;color:var(--accent);font-weight:800}
.spectable{width:100%;border-collapse:collapse;font-size:14.5px;margin:6px 0 22px;background:#fff}
.spectable th,.spectable td{border:1px solid var(--line);padding:10px 13px;text-align:left}
.spectable th{background:#eef6ff;color:var(--dark);font-weight:700;width:34%}
.techbox{background:#fff;border:1px solid var(--line);border-left:4px solid var(--accent);border-radius:10px;padding:20px 24px;margin:0 0 22px;box-shadow:var(--shadow)}
.techbox h3{margin:0 0 10px;font-size:17px;color:var(--dark)}
.techbox p,.techbox li{font-size:14.5px;color:var(--ink);line-height:1.85}
.techbox ul{margin:8px 0 0;padding-left:20px}
.pnav{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-top:26px}
.pnav a{display:block;background:#fff;border:1px solid var(--line);border-radius:10px;padding:16px 18px;text-decoration:none;color:var(--dark);font-weight:700;font-size:15px;box-shadow:var(--shadow)}
.pnav a:hover{border-color:var(--brand)}
.pnav a small{display:block;font-weight:400;color:var(--muted);font-size:12.5px;margin-top:5px}
@media(max-width:900px){.pdetail{grid-template-columns:1fr}.pnav{grid-template-columns:1fr}.pdetail h1{font-size:27px}}

.about-photos{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:20px;margin-top:36px}
.about-photos figure{margin:0;border-radius:14px;overflow:hidden;border:1px solid var(--line);background:#fff;box-shadow:var(--shadow)}
.about-photos img{width:100%;height:250px;object-fit:cover;display:block}
.about-photos video{width:100%;height:250px;object-fit:cover;display:block;background:#0b1a2a}
.about-photos figcaption{padding:13px 18px;font-size:14px;color:var(--muted);border-top:1px solid var(--line);background:#fff}
@media(max-width:760px){.about-photos{grid-template-columns:1fr}.about-photos img{height:200px}}

/* products */
.prod-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.prod-card{background:#fff;border-radius:16px;overflow:hidden;border:1px solid var(--line);box-shadow:var(--shadow);display:flex;flex-direction:column}
.prod-visual{height:170px;position:relative;display:grid;place-items:center}
.vis-cotton{background:linear-gradient(180deg,rgba(9,20,34,.28) 0%,rgba(9,20,34,.74) 100%),url('../img/prod-foam.jpg') center/cover no-repeat}
.vis-pipe{background:linear-gradient(180deg,rgba(9,20,34,.22) 0%,rgba(9,20,34,.66) 100%),url('../img/prod-tube.jpg') center/cover no-repeat}
.vis-xps{background:linear-gradient(180deg,rgba(9,20,34,.22) 0%,rgba(9,20,34,.68) 100%),url('../img/prod-xps.jpg') center/cover no-repeat}
.prod-visual::after{content:"";width:120px;height:120px;border-radius:50%;background:rgba(255,255,255,.12);position:absolute}
.prod-badge{position:relative;z-index:2;color:#fff;font-weight:800;font-size:22px;letter-spacing:2px;padding:8px 22px;border:2px solid rgba(255,255,255,.5);border-radius:8px}
.prod-detail{display:inline-block;color:var(--brand);font-weight:700;font-size:14px;text-decoration:none;margin:0 0 10px}
.prod-detail:hover{text-decoration:underline}
.prod-body{padding:24px 24px 28px;flex:1}
.prod-body h3{font-size:21px;margin-bottom:10px;color:var(--dark)}
.prod-body p{color:var(--muted);font-size:15px;margin-bottom:16px}
.prod-spec{list-style:none;font-size:14px;color:var(--ink)}
.prod-spec li{padding:7px 0;border-bottom:1px dashed var(--line);display:flex;gap:8px}
.prod-spec li b{color:var(--dark);min-width:52px}
.prod-note{margin-top:32px;background:#eef6ff;border:1px solid #cfe3fb;border-radius:12px;padding:18px 24px;color:var(--ink);font-size:15px}
.link-btn{background:none;border:none;color:var(--brand);font-size:15px;cursor:pointer;font-weight:700;padding:0}

/* advantages */
.adv-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.adv-item{background:#fff;padding:28px;border-radius:14px;border:1px solid var(--line)}
.adv-num{font-size:30px;font-weight:800;color:transparent;-webkit-text-stroke:2px var(--brand);margin-bottom:12px}
.adv-item h4{font-size:18px;color:var(--dark);margin-bottom:8px}
.adv-item p{color:var(--muted);font-size:15px}

/* cooperate */
.coop-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.coop-card{background:#fff;border-radius:14px;padding:28px 22px;border:1px solid var(--line);text-align:center}
.coop-ico{font-size:34px;margin-bottom:12px}
.coop-card h4{font-size:18px;color:var(--dark);margin-bottom:8px}
.coop-card p{color:var(--muted);font-size:14px}

/* contact */
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:40px}
.contact-info{display:flex;flex-direction:column;gap:20px}
.ci-item{display:flex;gap:14px;align-items:flex-start}
.ci-ico{width:44px;height:44px;border-radius:10px;background:#eef6ff;display:grid;place-items:center;font-size:20px;flex-shrink:0}
.ci-item b{display:block;color:var(--dark);margin-bottom:2px}
.ci-item p{color:var(--muted)}
.contact-form{background:#fff;border:1px solid var(--line);border-radius:16px;padding:30px;box-shadow:var(--shadow)}
.contact-form h3{font-size:20px;margin-bottom:18px;color:var(--dark)}
.contact-form label{font-weight:600;font-size:14px;display:block;margin:12px 0 6px;color:var(--ink)}
.contact-form input,.contact-form textarea{width:100%;padding:11px 14px;border:1px solid var(--line);border-radius:8px;font-size:15px;background:#fbfdff}
.contact-form input:focus,.contact-form textarea:focus{outline:none;border-color:var(--brand)}
.form-tip{font-size:13px;color:var(--muted);margin-top:12px;text-align:center}

/* footer */
footer{background:var(--dark);color:#a9bed9;padding:40px 0;text-align:center}
.footer-inner{display:flex;flex-direction:column;gap:10px}
.footer-links a{color:#cfe3fb}
.footer-meta{font-size:13px;color:#7d93b3}

/* reveal animation */
.reveal{opacity:0;transform:translateY(24px);transition:opacity .6s,transform .6s}
.reveal.in{opacity:1;transform:none}

/* product CTA */
.btn-sm{padding:9px 20px;font-size:14px}
.prod-cta{margin-top:16px}

/* news */
.news-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.news-card{background:#fff;border:1px solid var(--line);border-radius:14px;padding:26px;box-shadow:var(--shadow)}
.news-date{display:inline-block;background:linear-gradient(135deg,var(--brand),var(--accent));color:#fff;font-size:13px;font-weight:700;padding:4px 12px;border-radius:20px;margin-bottom:12px}
.news-card h4{font-size:18px;color:var(--dark);margin-bottom:8px}
.news-card p{color:var(--muted);font-size:14px}

/* faq */
.faq-grid{max-width:900px;margin:0 auto;display:flex;flex-direction:column;gap:12px}
.faq-item{background:#fff;border:1px solid var(--line);border-radius:12px;padding:0 22px;overflow:hidden}
.faq-item summary{cursor:pointer;font-size:16px;font-weight:700;color:var(--dark);padding:18px 0;list-style:none;display:flex;align-items:center;justify-content:space-between}
.faq-item summary::after{content:"+";font-size:22px;color:var(--brand);transition:.2s}
.faq-item[open] summary::after{content:"−"}
.faq-item p{padding:0 0 18px;color:var(--muted);font-size:15px}

/* responsive */
@media(max-width:900px){
  .about-grid{grid-template-columns:repeat(2,1fr)}
  .prod-grid{grid-template-columns:1fr}
  .adv-grid{grid-template-columns:repeat(2,1fr)}
  .coop-grid{grid-template-columns:repeat(2,1fr)}
  .contact-grid{grid-template-columns:1fr}
  .hero h1{font-size:38px}
  .nav-links{display:none;position:absolute;top:64px;left:0;right:0;background:#fff;flex-direction:column;gap:0;border-bottom:1px solid var(--line)}
  .nav-links.show{display:flex}
  .nav-links a{padding:15px 24px;border-top:1px solid var(--line)}
  .nav-toggle{display:block}
}
@media(max-width:560px){
  .about-grid,.adv-grid,.coop-grid{grid-template-columns:1fr}
  .hero h1{font-size:32px}
  .hero-desc{font-size:17px}
  .hero-stats{gap:24px}
}