/* ===========================================================
   PTFE LINE INDUSTRIAL — 站点样式
   配色：navy 主色 + orange 强调；浅底为主，深色块做视觉节奏
   =========================================================== */

:root{
  --navy:#0A2540;
  --navy-2:#123A5C;
  --navy-3:#1B4A72;
  --orange:#FF7A00;
  --orange-d:#E06A00;
  --ink:#16222E;
  --muted:#5A6B7B;
  --bg:#FFFFFF;
  --soft:#F4F7FA;
  --line:#E3E9EF;
  --max:1200px;
}

*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  font-family:"Inter","Helvetica Neue",Helvetica,Arial,"PingFang SC","Microsoft YaHei",sans-serif;
  color:var(--ink);background:var(--bg);line-height:1.65;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
.wrap{max-width:var(--max);margin:0 auto;padding:0 24px}
.muted{color:var(--muted)}

/* ---------- 顶部导航 ---------- */
header{
  position:sticky;top:0;z-index:50;background:#fff;
  border-bottom:1px solid var(--line);
}
.nav{display:flex;align-items:center;justify-content:space-between;height:70px}
.logo{display:flex;align-items:center;gap:10px;font-weight:800;letter-spacing:.02em}
.logo .mark{
  width:34px;height:34px;border-radius:6px;background:var(--navy);
  color:#fff;display:flex;align-items:center;justify-content:center;
  font-size:14px;font-weight:800;letter-spacing:-.02em;
}
.logo span{font-size:18px;color:var(--navy);line-height:1.1}
.logo small{display:block;font-size:10px;letter-spacing:.18em;color:var(--muted);font-weight:600}
.nav ul{display:flex;gap:26px;list-style:none}
.nav ul a{font-size:14px;font-weight:600;color:var(--ink);padding:6px 0;border-bottom:2px solid transparent}
.nav ul a:hover,.nav ul a.active{color:var(--orange);border-bottom-color:var(--orange)}
.btn{
  display:inline-block;background:var(--orange);color:#fff;font-weight:700;font-size:14px;
  padding:11px 22px;border-radius:4px;border:1px solid var(--orange);cursor:pointer;
  transition:.18s;white-space:nowrap;
}
.btn:hover{background:var(--orange-d);border-color:var(--orange-d)}
.btn.ghost{background:transparent;color:var(--navy);border-color:#C9D4DE}
.btn.ghost:hover{background:var(--navy);color:#fff;border-color:var(--navy)}
.btn.navy{background:var(--navy);border-color:var(--navy)}
.btn.navy:hover{background:var(--navy-2)}

/* ---------- HERO ---------- */
.hero{background:var(--soft);border-bottom:1px solid var(--line)}
.hero-grid{
  display:grid;grid-template-columns:1.05fr .95fr;gap:44px;align-items:center;
  padding:62px 0 56px;
}
.eyebrow{
  display:inline-block;font-size:12px;font-weight:700;letter-spacing:.16em;
  color:var(--orange);background:#FFF1E4;padding:6px 12px;border-radius:3px;margin-bottom:18px;
}
h1.hero-title{font-size:44px;line-height:1.14;font-weight:800;color:var(--navy);letter-spacing:-.01em}
h1.hero-title .hl{color:var(--orange)}
.hero-sub{font-size:17px;color:var(--muted);margin-top:18px;max-width:520px}
.hero-cta{display:flex;gap:12px;margin-top:26px;flex-wrap:wrap}
.hero-tags{display:flex;flex-wrap:wrap;gap:10px 22px;margin-top:28px;list-style:none}
.hero-tags li{font-size:13.5px;font-weight:600;color:var(--navy);display:flex;align-items:center;gap:8px}
.hero-tags li::before{
  content:"✓";color:var(--orange);font-weight:800;font-size:14px;line-height:1;
}
.hero-media{position:relative}
.hero-media img{border-radius:8px;width:100%;object-fit:cover;aspect-ratio:16/9;box-shadow:0 14px 40px rgba(10,37,64,.18)}
.hero-cards{
  position:absolute;right:16px;bottom:-26px;display:grid;gap:8px;width:238px;
}
.hcard{
  background:#fff;border:1px solid var(--line);border-radius:6px;padding:11px 14px;
  box-shadow:0 8px 22px rgba(10,37,64,.12);
}
.hcard b{display:block;font-size:10.5px;letter-spacing:.12em;color:var(--muted);text-transform:uppercase}
.hcard strong{display:block;font-size:19px;color:var(--navy);line-height:1.25;margin-top:2px}
.hcard span{font-size:11.5px;color:var(--muted)}

/* ---------- 深色卖点条 ---------- */
.strip{background:var(--navy);color:#fff}
.strip-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:0}
.strip-grid div{
  padding:26px 20px;border-right:1px solid rgba(255,255,255,.12);
}
.strip-grid div:last-child{border-right:none}
.strip-grid b{display:block;font-size:14px;font-weight:700;margin-bottom:5px}
.strip-grid span{font-size:12.5px;color:#B7C7D6;line-height:1.5;display:block}

/* ---------- 通用区块 ---------- */
section{padding:70px 0}
.sec-head{max-width:720px;margin-bottom:38px}
.sec-head .kicker{font-size:12px;font-weight:700;letter-spacing:.18em;color:var(--orange);margin-bottom:10px}
.sec-head h2{font-size:32px;line-height:1.22;color:var(--navy);font-weight:800;letter-spacing:-.01em}
.sec-head p{color:var(--muted);margin-top:12px;font-size:16px}
.center{text-align:center}
.center .sec-head{margin-left:auto;margin-right:auto}

/* ---------- 产品卡片网格 ---------- */
.cards{display:grid;grid-template-columns:repeat(4,1fr);gap:22px}
.card{
  background:#fff;border:1px solid var(--line);border-radius:8px;overflow:hidden;
  transition:.2s;display:flex;flex-direction:column;
}
.card:hover{transform:translateY(-4px);box-shadow:0 14px 30px rgba(10,37,64,.12);border-color:#CBD8E4}
.card .thumb{aspect-ratio:4/3;overflow:hidden;background:var(--soft)}
.card .thumb img{width:100%;height:100%;object-fit:cover}
.card .body{padding:18px}
.card h3{font-size:16.5px;color:var(--navy);font-weight:700;margin-bottom:7px}
.card p{font-size:13.5px;color:var(--muted);line-height:1.6}
.card .more{margin-top:12px;font-size:13px;font-weight:700;color:var(--orange)}

/* ---------- 规格表 ---------- */
.spec-wrap{display:grid;grid-template-columns:1fr 1fr;gap:26px}
.spec-box{border:1px solid var(--line);border-radius:8px;overflow:hidden;background:#fff}
.spec-box h3{
  background:var(--soft);padding:15px 20px;font-size:15px;color:var(--navy);font-weight:800;
  border-bottom:1px solid var(--line);letter-spacing:.02em;
}
table{width:100%;border-collapse:collapse;font-size:14px}
table th,table td{padding:12px 20px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}
table th{width:40%;color:var(--muted);font-weight:600;font-size:13.5px}
table td{color:var(--ink);font-weight:600}
table tr:last-child th,table tr:last-child td{border-bottom:none}
.note{font-size:12.5px;color:var(--muted);padding:12px 20px;background:#FCFDFE;border-top:1px solid var(--line)}

/* ---------- 应用场景（深色图块） ---------- */
.scene{
  position:relative;background:var(--navy);color:#fff;overflow:hidden;
}
.scene .bg{
  position:absolute;inset:0;
}
.scene .bg img{width:100%;height:100%;object-fit:cover;opacity:.26}
.scene .bg::after{content:"";position:absolute;inset:0;background:linear-gradient(90deg,rgba(10,37,64,.93) 0%,rgba(10,37,64,.72) 60%,rgba(10,37,64,.55) 100%)}
.scene .wrap{position:relative;z-index:2}
.scene h2{font-size:32px;font-weight:800;margin-bottom:10px}
.scene p.lead{color:#C6D6E4;max-width:640px;margin-bottom:30px}
.ind-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.ind{
  background:rgba(255,255,255,.07);border:1px solid rgba(255,255,255,.14);
  border-radius:6px;padding:18px 18px;
}
.ind b{display:block;font-size:15px;margin-bottom:5px}
.ind span{font-size:12.8px;color:#B7C7D6;line-height:1.55;display:block}

/* ---------- Why us ---------- */
.why{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.why-item{border-left:3px solid var(--orange);padding:4px 0 4px 18px}
.why-item b{display:block;font-size:16px;color:var(--navy);margin-bottom:6px}
.why-item p{font-size:14px;color:var(--muted);line-height:1.65}

/* ---------- One container 强调 ---------- */
.onecont{background:var(--soft);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.oc-grid{display:grid;grid-template-columns:1fr 1fr;gap:40px;align-items:center}
.oc-grid img{border-radius:8px;box-shadow:0 12px 30px rgba(10,37,64,.14)}
.oc-list{list-style:none;margin-top:20px}
.oc-list li{
  padding:10px 0 10px 30px;position:relative;font-size:14.5px;color:var(--ink);
  border-bottom:1px dashed var(--line);
}
.oc-list li::before{
  content:"✓";position:absolute;left:0;top:10px;color:var(--orange);font-weight:800;
}

/* ---------- FAQ ---------- */
.faq{max-width:860px}
.faq details{border:1px solid var(--line);border-radius:6px;margin-bottom:12px;background:#fff}
.faq summary{
  cursor:pointer;padding:16px 20px;font-weight:700;font-size:15px;color:var(--navy);
  list-style:none;display:flex;justify-content:space-between;align-items:center;gap:16px;
}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";color:var(--orange);font-size:20px;font-weight:800;line-height:1}
.faq details[open] summary::after{content:"–"}
.faq .ans{padding:0 20px 18px;font-size:14.2px;color:var(--muted);line-height:1.75}

/* ---------- CTA ---------- */
.cta{background:var(--navy);color:#fff;text-align:center}
.cta h2{font-size:30px;font-weight:800;margin-bottom:12px}
.cta p{color:#C6D6E4;max-width:620px;margin:0 auto 26px}
.cta-row{display:flex;gap:12px;justify-content:center;flex-wrap:wrap}
.cta .wa{
  display:inline-block;background:#25D366;color:#fff;font-weight:700;font-size:14px;
  padding:11px 22px;border-radius:4px;border:1px solid #25D366;
}
.cta .wa:hover{background:#1EBB57;border-color:#1EBB57}

/* ---------- 页脚 ---------- */
footer{background:#071B2F;color:#9FB3C6;padding:52px 0 26px;font-size:13.5px}
.f-grid{display:grid;grid-template-columns:1.6fr 1fr 1fr 1.2fr;gap:30px}
footer h4{color:#fff;font-size:14px;margin-bottom:14px;letter-spacing:.02em}
footer ul{list-style:none}
footer li{margin-bottom:8px}
footer a:hover{color:var(--orange)}
.f-bottom{
  border-top:1px solid rgba(255,255,255,.1);margin-top:34px;padding-top:18px;
  display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;color:#7C93A8;font-size:12.5px;
}

/* ---------- 内页通用 ---------- */
.page-hero{
  background:var(--navy);color:#fff;padding:52px 0 46px;
}
.page-hero h1{font-size:36px;font-weight:800;line-height:1.2}
.page-hero p{color:#C6D6E4;margin-top:12px;max-width:660px}
.breadcrumb{font-size:12.5px;color:#8FA6BC;margin-bottom:14px}
.breadcrumb a:hover{color:var(--orange)}

.two-col{display:grid;grid-template-columns:1fr 1fr;gap:34px;align-items:center}
.two-col img{border-radius:8px;box-shadow:0 12px 30px rgba(10,37,64,.14)}
.checklist{list-style:none;margin-top:16px}
.checklist li{
  padding:9px 0 9px 28px;position:relative;font-size:14.5px;border-bottom:1px dashed var(--line);
}
.checklist li::before{content:"✓";position:absolute;left:0;color:var(--orange);font-weight:800}

/* 联系页 */
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:40px}
.cbox{
  border:1px solid var(--line);border-radius:8px;padding:26px;background:#fff;
}
.cbox h3{font-size:17px;color:var(--navy);margin-bottom:14px;font-weight:800}
.cbox p{font-size:14.2px;color:var(--muted);margin-bottom:8px}
.cbox .big{font-size:20px;color:var(--navy);font-weight:800;margin:6px 0 4px}
.field{margin-bottom:14px}
.field label{display:block;font-size:13px;font-weight:700;color:var(--navy);margin-bottom:6px}
.field input,.field textarea,.field select{
  width:100%;padding:11px 13px;border:1px solid #D3DDE6;border-radius:4px;
  font-family:inherit;font-size:14px;color:var(--ink);background:#fff;
}
.field input:focus,.field textarea:focus{outline:none;border-color:var(--orange)}
.field textarea{min-height:110px;resize:vertical}

/* 占位提示（上线前删除） */
.placeholder{
  border:2px dashed #C9D4DE;border-radius:6px;background:#FBFDFE;
  padding:16px;text-align:center;color:var(--muted);font-size:13px;
}

/* ---------- 响应式 ---------- */
@media(max-width:1000px){
  .hero-grid{grid-template-columns:1fr;gap:30px}
  h1.hero-title{font-size:34px}
  .hero-cards{position:static;width:auto;grid-template-columns:repeat(3,1fr);margin-top:14px}
  .cards{grid-template-columns:repeat(2,1fr)}
  .strip-grid{grid-template-columns:repeat(2,1fr)}
  .strip-grid div{border-bottom:1px solid rgba(255,255,255,.12)}
  .spec-wrap,.two-col,.oc-grid,.contact-grid{grid-template-columns:1fr}
  .ind-grid,.why{grid-template-columns:repeat(2,1fr)}
  .f-grid{grid-template-columns:1fr 1fr}
  .nav ul{display:none}
}
@media(max-width:640px){
  h1.hero-title{font-size:28px}
  .sec-head h2,.scene h2{font-size:25px}
  section{padding:48px 0}
  .cards,.ind-grid,.why,.hero-cards{grid-template-columns:1fr}
  .f-grid{grid-template-columns:1fr}
  .page-hero h1{font-size:27px}
}