/*
  YSBackupBoard Inner Page Design System v5
  Visual system is intentionally derived from the preserved homepage:
  black #191818 + YUESHAN orange #f8b551 + white/soft gray + Helvetica/Microsoft YaHei.
  This file changes presentation only; SEO/GEO content and URL structure remain intact.
*/
:root{
  --ink:#191818;
  --ink-2:#2b2a2a;
  --muted:#797979;
  --line:#d9d9d9;
  --soft:#f3f3f3;
  --soft-warm:#fff7ea;
  --brand:#191818;
  --brand2:#f8b551;
  --accent:#f8b551;
  --accent-dark:#d99632;
  --ok:#4e7455;
  --danger:#9a3f37;
  --max:1200px;
  --shadow:0 10px 28px rgba(0,0,0,.10);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  color:var(--ink);
  font:16px/1.68 "Helvetica Regula","Helvetica Neue",Helvetica,Arial,"Microsoft YaHei",sans-serif;
  background:#fff;
  -webkit-font-smoothing:antialiased;
}
a{color:#b56f13;text-decoration:none}
a:hover{color:#8c5209;text-decoration:underline}
img{max-width:100%;height:auto}
.wrap{width:min(var(--max),calc(100% - 40px));margin:auto}
.skip{position:absolute;left:-9999px}
.skip:focus{left:12px;top:12px;background:#fff;color:#000;padding:8px 12px;z-index:999;border:2px solid var(--accent)}

/* Header: mirrors the homepage black navigation and orange hover state */
.topbar{background:#0d0d0d;color:#9a9a9a;font-size:13px;border-bottom:1px solid #262626}
.topbar .wrap{display:flex;justify-content:space-between;gap:18px;padding:7px 0;flex-wrap:wrap}
.topbar a{color:#d8d8d8}.topbar a:hover{color:var(--accent)}
.header{position:sticky;top:0;z-index:50;background:rgba(25,24,24,.98);border-bottom:1px solid #303030;box-shadow:0 4px 14px rgba(0,0,0,.12)}
.nav{display:flex;align-items:center;gap:28px;min-height:70px}
.logo{display:flex;align-items:center;margin-right:auto}
.logo img{width:61px;height:48px;object-fit:contain}
.navlinks{display:flex;gap:28px;align-items:center;flex-wrap:wrap}
.navlinks a{font-size:15px;font-weight:600;color:#fff;letter-spacing:.01em}
.navlinks a:hover{color:var(--accent);text-decoration:none}
.navlinks .cta{background:var(--accent);color:#161616;padding:10px 16px;border:1px solid var(--accent);font-weight:700}
.navlinks .cta:hover{background:#fff;color:#191818;border-color:#fff}

/* Inner hero: same image and black/orange tone as original homepage */
.hero{background:linear-gradient(90deg,rgba(0,0,0,.88),rgba(0,0,0,.64)),url('/images/header-bg.jpg') center/cover no-repeat;color:#fff;padding:80px 0 70px;border-bottom:12px solid var(--accent)}
.hero.inner{background:linear-gradient(90deg,rgba(0,0,0,.90),rgba(25,24,24,.70)),url('/images/header-bg.jpg') center/cover no-repeat;padding:64px 0 58px}
.eyebrow{letter-spacing:.13em;text-transform:uppercase;font-weight:700;font-size:12px;color:var(--accent)}
.hero h1{font-size:clamp(36px,5vw,60px);line-height:1.08;margin:10px 0 18px;max-width:980px;color:#fff;font-weight:700;letter-spacing:-.02em}
.hero.inner h1{font-size:clamp(34px,4.2vw,52px)}
.hero h1:after{content:"";display:block;width:86px;height:7px;background:var(--accent);margin-top:20px}
.lead{font-size:19px;max-width:880px;color:#b9b9b9;margin:0}
.breadcrumb{font-size:13px;color:#9b9b9b;margin-bottom:10px}
.breadcrumb a{color:var(--accent)}
.breadcrumb a:hover{color:#fff}
.actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:28px}
.btn{display:inline-block;padding:12px 20px;font-weight:700;border:1px solid transparent;border-radius:0;transition:.18s ease}
.btn.primary{background:var(--accent);border-color:var(--accent);color:#191818}
.btn.primary:hover{background:#fff;border-color:#fff;color:#191818;text-decoration:none}
.btn.secondary{background:transparent;border-color:#777;color:#fff}
.btn.secondary:hover{border-color:var(--accent);color:var(--accent);text-decoration:none}
.btn.dark{background:#191818;border-color:#191818;color:#fff}
.btn.dark:hover{background:var(--accent);border-color:var(--accent);color:#191818;text-decoration:none}
.btn.light{background:#fff;border-color:#bfbfbf;color:#191818}
.btn.light:hover{border-color:var(--accent);color:#8c5209;text-decoration:none}

/* Content rhythm */
.section{padding:68px 0}
.section.soft{background:var(--soft)}
.section.tight{padding:44px 0}
.section h2{font-size:clamp(28px,3vw,38px);line-height:1.2;margin:0 0 20px;color:#191818;font-weight:700}
.section h2:before{content:"";display:inline-block;width:6px;height:28px;background:var(--accent);margin-right:12px;vertical-align:-3px}
.section h3{font-size:21px;line-height:1.3;margin:0 0 11px;color:#191818}
.intro{max-width:880px;color:var(--muted);font-size:17px}

/* GEO answer block: warm YUESHAN orange instead of unrelated blue */
.geo{background:#fff8ed;border-left:6px solid var(--accent);padding:21px 24px;margin:0 0 28px;color:#333}
.geo strong{color:#191818}
.toc{border:1px solid #d8d8d8;border-top:4px solid var(--accent);padding:18px 20px;background:#fff}
.toc strong{color:#191818}
.toc a{display:inline-block;margin:4px 12px 4px 0;color:#9a5e10}

.grid{display:grid;gap:22px}
.g2{grid-template-columns:repeat(2,minmax(0,1fr))}
.g3{grid-template-columns:repeat(3,minmax(0,1fr))}
.g4{grid-template-columns:repeat(4,minmax(0,1fr))}
.card{background:#fff;border:1px solid #d6d6d6;border-top:4px solid var(--accent);border-radius:0;padding:24px;box-shadow:0 3px 12px rgba(0,0,0,.045)}
.card h3{margin-top:0}.card p:last-child{margin-bottom:0}
.linkcard{display:block;color:inherit;transition:.18s ease}
.linkcard:hover{text-decoration:none;border-color:var(--accent);box-shadow:var(--shadow);transform:translateY(-2px)}
.kicker,.mini-label{font-size:12px;font-weight:800;letter-spacing:.09em;text-transform:uppercase;color:#b46c0e}
.metric{font-size:29px;font-weight:800;color:#191818}
.badge{display:inline-block;padding:3px 8px;border:1px solid #e0b36d;background:#fff7e9;color:#8a520c;font-size:11px;font-weight:800;text-transform:uppercase;letter-spacing:.05em}
.tag{display:inline-block;border:1px solid #ddb675;background:#fff7e9;color:#75480e;border-radius:0;padding:4px 9px;font-size:12px;margin:3px 4px 3px 0}

/* Tables: original homepage black/orange visual language */
.tablewrap{overflow-x:auto;border:1px solid #d3d3d3;background:#fff}
.data{width:100%;border-collapse:collapse;min-width:720px}
.data th,.data td{padding:14px 15px;border-bottom:1px solid #dddddd;text-align:left;vertical-align:top}
.data th{background:#191818;color:var(--accent);font-size:13px;font-weight:700;border-right:1px solid #343434}
.data th:last-child{border-right:0}
.data tbody tr:nth-child(even){background:#fafafa}
.data tbody tr:hover{background:#fff7e9}
.data tr:last-child td{border-bottom:0}
.data a{font-weight:600}
.note{font-size:13px;color:var(--muted);margin-top:11px}

.warning{background:#fff6e7;border-left:5px solid var(--accent);padding:17px 19px;border-radius:0}
.success{background:#f2f6f2;border-left:5px solid var(--ok);padding:17px 19px;border-radius:0}
.risk{background:#fff0ed;border-left:5px solid var(--danger);padding:17px 19px;border-radius:0}
.evidence{background:#f6f6f6;border:1px dashed #aaa;padding:19px;border-radius:0}
.jargon{background:#f6f6f6;border:1px solid #d5d5d5;border-top:4px solid var(--accent);border-radius:0;padding:22px;margin-top:22px}
.jargon h3{margin-top:0}
.plain-terms{font-size:14px;color:#5f5f5f}.plain-terms strong{color:#191818}

.checklist{padding-left:21px}.checklist li{margin:8px 0;list-style:disc}.checklist li::marker{color:var(--accent)}
.product-img{aspect-ratio:4/3;width:100%;object-fit:cover;border:8px solid #191818;background:#eee}
.media{display:grid;grid-template-columns:1.05fr .95fr;gap:36px;align-items:center}
.gallery{display:grid;grid-template-columns:repeat(4,1fr);gap:10px}
.gallery img{aspect-ratio:4/3;width:100%;object-fit:cover;border:5px solid #fff;outline:1px solid #d4d4d4;background:#eee}

.quote,.costbox{background:#191818;color:#fff;padding:30px;border:0;border-left:10px solid var(--accent);border-radius:0;box-shadow:none}
.quote h2,.costbox h3{color:#fff}.quote h2:before{background:var(--accent)}
.quote p,.costbox p{color:#bcbcbc}
.formula{font-size:20px;font-weight:800;line-height:1.45;margin:16px 0;color:var(--accent)}

.faq details{border-top:1px solid #d6d6d6;padding:17px 0}
.faq details:last-child{border-bottom:1px solid #d6d6d6}
.faq summary{cursor:pointer;font-weight:700;color:#191818;list-style-position:outside}
.faq summary:hover{color:#9a5e10}
.faq details[open] summary{color:#9a5e10}
.faq p{color:var(--muted)}
.steps{counter-reset:step}
.step{position:relative;padding:0 0 26px 58px}
.step:before{counter-increment:step;content:counter(step);position:absolute;left:0;top:0;width:38px;height:38px;display:grid;place-items:center;background:#191818;border:3px solid var(--accent);color:var(--accent);font-weight:800}

.sourcebar{background:#f3f3f3;border-top:10px solid var(--accent)}
.source-list{font-size:14px;color:var(--muted)}.source-list li{margin:7px 0}.source-list a{word-break:break-word}

/* Footer: matches homepage dark base */
.footer{background:#191818;color:#9d9d9d;padding:50px 0 30px;border-top:12px solid var(--accent)}
.footer a{color:#fff}.footer a:hover{color:var(--accent)}
.footer h3{color:var(--accent);font-size:16px;text-transform:uppercase;letter-spacing:.04em}
.footergrid{display:grid;grid-template-columns:2fr 1fr 1fr 1.3fr;gap:30px}
.copyright{border-top:1px solid #3a3a3a;margin-top:30px;padding-top:18px;font-size:13px;color:#777}
.sticky-rfq{position:fixed;right:18px;bottom:18px;z-index:40;background:var(--accent);color:#191818;padding:12px 17px;border:2px solid #191818;border-radius:0;font-weight:800;box-shadow:0 6px 16px rgba(0,0,0,.22)}
.sticky-rfq:hover{background:#191818;color:var(--accent);border-color:var(--accent);text-decoration:none}
.small{font-size:13px;color:var(--muted)}.center{text-align:center}.spacer{height:6px}

@media(max-width:900px){
  .wrap{width:min(var(--max),calc(100% - 28px))}
  .nav{align-items:center;flex-wrap:wrap;padding:10px 0 12px;gap:12px}
  .logo{margin-right:auto}
  .navlinks{width:100%;gap:12px 18px;padding-top:9px;border-top:1px solid #343434}
  .navlinks a{font-size:14px}
  .g4{grid-template-columns:repeat(2,1fr)}
  .g3{grid-template-columns:1fr}
  .g2,.media{grid-template-columns:1fr}
  .footergrid{grid-template-columns:1fr 1fr}
  .hero,.hero.inner{padding:54px 0 48px}
  .gallery{grid-template-columns:repeat(2,1fr)}
}
@media(max-width:560px){
  .g4{grid-template-columns:1fr}.footergrid{grid-template-columns:1fr}
  .wrap{width:min(var(--max),calc(100% - 22px))}
  .hero h1,.hero.inner h1{font-size:35px}
  .section{padding:48px 0}.section.tight{padding:34px 0}
  .section h2{font-size:28px}
  .sticky-rfq{left:10px;right:10px;text-align:center}
  .topbar .wrap{display:block}.topbar span{display:block;margin:2px 0}
  .navlinks{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px 12px}
  .navlinks .cta{text-align:center}
  .data th,.data td{padding:12px}
}