/* ChengRoll — Hunan ChengGang Conveyor Technology
   Industrial B2B design system: charcoal ink + industrial orange accent */

:root{
  --ink:#14191f;
  --ink-2:#2b333c;
  --muted:#6a747e;
  --line:#e3e8ec;
  --bg:#ffffff;
  --bg-soft:#f5f7f9;
  --bg-deep:#0e1418;
  --accent:#ff7a1a;
  --accent-dark:#d95f05;
  --accent-soft:#fff3e8;
  --steel:#2a5c8a;
  --ok:#0d7d4f;
  --radius:8px;
  --maxw:1220px;
  --shadow:0 1px 3px rgba(20,25,31,.07), 0 10px 30px rgba(20,25,31,.05);
  --shadow-lg:0 4px 12px rgba(20,25,31,.10), 0 24px 60px rgba(20,25,31,.12);
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  color:var(--ink);
  background:var(--bg);
  font-size:16px;
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;display:block;height:auto}
a{color:var(--steel);text-decoration:none}
a:hover{text-decoration:underline}
h1,h2,h3,h4{line-height:1.22;margin:0 0 .5em;letter-spacing:-.015em;font-weight:750}
h1{font-size:clamp(29px,4.2vw,46px)}
h2{font-size:clamp(23px,2.7vw,34px)}
h3{font-size:19px}
h4{font-size:16px}
p{margin:0 0 1em}
ul{margin:0 0 1em;padding-left:20px}
li{margin:5px 0}
small{font-size:13.5px}

.wrap{max-width:var(--maxw);margin:0 auto;padding:0 24px}
.section{padding:72px 0}
.section.soft{background:var(--bg-soft)}
.section.deep{background:var(--bg-deep);color:#dfe6ea}
.section.deep h2,.section.deep h3,.section.deep h4{color:#fff}
.section.deep p{color:#b9c5cc}
.eyebrow{
  display:inline-block;font-size:12.5px;font-weight:750;letter-spacing:.16em;
  text-transform:uppercase;color:var(--accent-dark);margin-bottom:12px;
}
.lead{font-size:17.5px;color:var(--ink-2);max-width:820px}

/* ---------- top bar + header ---------- */
.topbar{background:var(--bg-deep);color:#aab6bd;font-size:13px}
.topbar .wrap{display:flex;justify-content:space-between;align-items:center;height:38px;flex-wrap:wrap;gap:8px}
.topbar a{color:#dfe6ea}
.topbar .sep{opacity:.35;margin:0 8px}
.site-header{position:sticky;top:0;z-index:50;background:#fff;border-bottom:1px solid var(--line);box-shadow:0 1px 6px rgba(20,25,31,.05)}
.site-header .wrap{display:flex;align-items:center;justify-content:space-between;height:72px;gap:20px}
.brand{display:flex;align-items:center;gap:11px;text-decoration:none}
.brand img{height:38px;width:auto}
.brand-name{font-size:21px;font-weight:800;letter-spacing:-.02em;color:var(--ink)}
.brand-name span{color:var(--accent-dark)}
.brand-tag{display:block;font-size:11px;letter-spacing:.09em;text-transform:uppercase;color:var(--muted);font-weight:600}
.nav{display:flex;align-items:center;gap:30px}
.nav a{font-size:14.5px;font-weight:600;color:var(--ink-2);position:relative;padding:25px 0;text-decoration:none}
.nav a:hover,.nav a.active{color:var(--accent-dark);text-decoration:none}
.nav .has-menu{position:relative}
.nav .has-menu>a::after{content:"▾";font-size:10px;margin-left:6px;color:var(--muted)}
.nav .sub{
  display:none;position:absolute;top:100%;left:-18px;background:#fff;border:1px solid var(--line);
  border-radius:var(--radius);box-shadow:var(--shadow-lg);min-width:320px;padding:8px 0;z-index:60;
}
.nav .has-menu:hover>.sub,.nav .has-menu:focus-within>.sub{display:block}
.nav .sub a{display:block;padding:10px 20px;font-weight:650;font-size:14px;color:var(--ink-2)}
.nav .sub a span{display:block;font-weight:400;font-size:12.5px;color:var(--muted);margin-top:2px;line-height:1.45}
.nav .sub a:hover{background:var(--accent-soft);color:var(--accent-dark)}
.nav .sub a:hover span{color:var(--accent-dark)}
.nav-toggle{display:none}
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:11px 22px;border-radius:6px;font-weight:700;font-size:14.5px;
  border:1px solid transparent;cursor:pointer;text-decoration:none;transition:.15s;
}
.btn:hover{text-decoration:none;transform:translateY(-1px)}
.btn-primary{background:var(--accent);color:#fff}
.btn-primary:hover{background:var(--accent-dark);color:#fff}
.btn-dark{background:var(--bg-deep);color:#fff}
.btn-dark:hover{color:#fff}
.btn-ghost{border-color:var(--line);color:var(--ink)}
.btn-ghost:hover{border-color:var(--ink);color:var(--ink)}
.btn-lg{padding:14px 30px;font-size:16px}
.header-cta{display:flex;align-items:center;gap:14px}

/* ---------- hero ---------- */
.hero{position:relative;background:var(--bg-deep);color:#fff;overflow:hidden}
.hero-bg{position:absolute;inset:0}
.hero-bg img{width:100%;height:100%;object-fit:cover;opacity:.34}
.hero::after{content:"";position:absolute;inset:0;background:linear-gradient(105deg,rgba(14,20,24,.93) 0%,rgba(14,20,24,.72) 55%,rgba(14,20,24,.45) 100%)}
.hero .wrap{position:relative;z-index:2;padding-top:96px;padding-bottom:88px}
.hero h1{color:#fff;max-width:940px;margin-bottom:18px}
.hero h1 em{font-style:normal;color:var(--accent)}
.hero .sub{font-size:18px;color:#c3ced5;max-width:760px;margin-bottom:30px}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap;margin-bottom:40px}
.hero-facts{display:grid;grid-template-columns:repeat(4,1fr);gap:1px;background:rgba(255,255,255,.14);border:1px solid rgba(255,255,255,.14);border-radius:var(--radius);overflow:hidden}
.hero-facts div{background:rgba(14,20,24,.55);padding:18px 20px}
.hero-facts b{display:block;font-size:27px;font-weight:800;color:#fff;line-height:1.15}
.hero-facts span{font-size:12.5px;color:#a9b6bd;letter-spacing:.04em;text-transform:uppercase}

/* ---------- trust / client wall ---------- */
.client-wall{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:14px;margin-top:26px}
.client-wall div{
  border:1px solid var(--line);border-radius:var(--radius);padding:18px 14px;text-align:center;
  font-weight:750;font-size:15px;letter-spacing:.02em;background:#fff;color:var(--ink-2);
}
.client-wall div small{display:block;font-weight:500;font-size:12px;color:var(--muted);margin-top:4px;letter-spacing:0}

/* ---------- cards / grids ---------- */
.grid{display:grid;gap:24px}
.g2{grid-template-columns:repeat(2,1fr)}
.g3{grid-template-columns:repeat(3,1fr)}
.g4{grid-template-columns:repeat(4,1fr)}
.card{
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  overflow:hidden;transition:.18s;display:flex;flex-direction:column;
}
.card:hover{box-shadow:var(--shadow-lg);transform:translateY(-3px);text-decoration:none}
.card-media{aspect-ratio:4/3;overflow:hidden;background:var(--bg-soft)}
.card-media img{width:100%;height:100%;object-fit:cover;transition:transform .4s}
.card:hover .card-media img{transform:scale(1.05)}
.card-body{padding:20px 22px 24px}
.card-body h3{margin-bottom:6px}
.card-body p{font-size:14.5px;color:var(--muted);margin-bottom:12px}
.card-link{font-weight:700;font-size:14px;color:var(--accent-dark)}
.card.plain{padding:26px}
.card.plain h3{margin-bottom:8px}
.card.plain p{font-size:14.5px;color:var(--muted);margin-bottom:0}
.step-num{
  font-size:13px;font-weight:800;color:var(--accent-dark);letter-spacing:.1em;
  display:block;margin-bottom:6px;
}

/* ---------- spec table ---------- */
.table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:var(--radius)}
table.spec,
table.spec-table{width:100%;border-collapse:collapse;font-size:14.5px;min-width:560px}
table.spec th,
table.spec-table th{background:var(--ink);color:#fff;text-align:left;padding:12px 16px;font-weight:650}
table.spec td,
table.spec-table td{border-top:1px solid var(--line);padding:11px 16px;vertical-align:top}
table.spec tr:nth-child(even) td,
table.spec-table tr:nth-child(even) td{background:var(--bg-soft)}
table.spec td:first-child,
table.spec-table td:first-child{font-weight:650;white-space:nowrap}

/* ---------- rpm matrix ---------- */
table.rpm-matrix{width:100%;border-collapse:collapse;font-size:13px;min-width:780px}
table.rpm-matrix th{background:var(--ink);color:#fff;padding:9px 10px;font-weight:650;text-align:center;white-space:nowrap}
table.rpm-matrix th:first-child{text-align:left}
table.rpm-matrix td{border-top:1px solid var(--line);padding:8px 10px;text-align:center;white-space:nowrap;font-variant-numeric:tabular-nums}
table.rpm-matrix td:first-child{text-align:left;font-weight:650;background:var(--bg-soft)}
table.rpm-matrix td.r-ok{background:#e9f7f0;color:#0b6b44;font-weight:600}
table.rpm-matrix td.r-watch{background:#fdf2cd;color:#6b5a10;font-weight:600}
table.rpm-matrix td.r-over{background:#fff3e5;color:#9c4a08;font-weight:600}
table.rpm-matrix td.r-no{background:#fce9e9;color:#a01e1e;font-weight:700}
.rpm-legend{display:flex;flex-wrap:wrap;gap:8px 20px;margin:12px 0 4px;font-size:13px;color:var(--muted)}
.rpm-legend span{display:inline-flex;align-items:center;gap:7px}
.rpm-legend i.sw{width:13px;height:13px;border-radius:3px;display:inline-block;border:1px solid rgba(0,0,0,.08)}
.rpm-legend i.r-ok{background:#e9f7f0}
.rpm-legend i.r-watch{background:#fdf2cd}
.rpm-legend i.r-over{background:#fff3e5}
.rpm-legend i.r-no{background:#fce9e9}
p.caption{font-size:13px;color:var(--muted);margin:8px 0 0}

/* ---------- process steps ---------- */
.steps{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:18px;counter-reset:s}
.step{
  border:1px solid var(--line);border-radius:var(--radius);padding:20px 22px;background:#fff;
  border-left:4px solid var(--accent);
}
.step b{display:block;font-size:15px;margin-bottom:6px}
.step span{font-size:14px;color:var(--muted)}
.step .n{font-size:12.5px;font-weight:800;color:var(--accent-dark);letter-spacing:.1em;margin-bottom:6px;display:block}

/* ---------- misc ---------- */
.breadcrumb{font-size:13px;color:var(--muted);padding:14px 0;border-bottom:1px solid var(--line)}
.breadcrumb a{color:var(--muted)}
.cert-strip{display:flex;flex-wrap:wrap;gap:22px;align-items:center;justify-content:center}
.cert-strip img{height:74px;width:auto;background:#fff;padding:8px 12px;border:1px solid var(--line);border-radius:6px}

/* ---------- certificate cards (real certificates) ---------- */
.cert-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(215px,1fr));gap:18px}
.cert-grid.g3{grid-template-columns:repeat(auto-fit,minmax(240px,1fr))}
.cert-card{display:flex;flex-direction:column;background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  overflow:hidden;text-decoration:none;color:inherit;transition:box-shadow .18s ease,border-color .18s ease}
.cert-card:hover{border-color:var(--accent);box-shadow:var(--shadow-lg)}
.cert-card img{width:100%;display:block;background:#eef1f4;border-bottom:1px solid var(--line)}
.cert-card>div{padding:12px 14px 14px;display:flex;flex-direction:column;gap:2px}
.cert-card b{font-size:14.5px;letter-spacing:.1px}
.cert-card span{font-size:12.5px;color:var(--muted);line-height:1.45}
.cert-card span.valid{color:var(--ok);font-weight:650;margin-top:3px}
.cert-card span.num{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:12px}
.cert-note{font-size:13px;color:var(--muted);text-align:center;margin-top:16px;line-height:1.6}
.ma-band{display:flex;flex-wrap:wrap;gap:16px;align-items:center;justify-content:space-between;
  background:var(--bg-soft);border:1px solid var(--line);border-left:4px solid var(--accent);
  border-radius:var(--radius);padding:16px 20px;margin-top:18px}
.ma-band>*{flex:1 1 320px}
.ma-band b{display:block;font-size:15px;margin-bottom:3px}
.ma-band span{font-size:13px;color:var(--muted);line-height:1.5}
.ma-band .btn{flex:0 0 auto}
.cta-band{background:var(--bg-deep);color:#fff;padding:56px 0;text-align:center}
.cta-band h2{color:#fff;margin-bottom:10px}
.cta-band p{color:#b9c5cc;margin-bottom:24px}
.notice{background:var(--accent-soft);border-left:4px solid var(--accent);padding:14px 18px;border-radius:0 8px 8px 0;font-size:14.5px;margin:16px 0}
.ph{background:#fff6d8;border-bottom:1px dashed #d9a800;padding:0 3px}
.split{display:grid;grid-template-columns:1.05fr .95fr;gap:48px;align-items:center}
.split img{border-radius:var(--radius);width:100%}
ul.ticks{list-style:none;padding-left:0}
ul.ticks li{position:relative;padding-left:26px;margin:8px 0}
ul.ticks li::before{content:"✓";position:absolute;left:0;top:-1px;color:var(--accent-dark);font-weight:800}

/* ---------- footer ---------- */
.site-footer{background:#0a0f13;color:#94a2ab;padding:56px 0 26px;font-size:14px}
.site-footer h4{color:#fff;font-size:14px;letter-spacing:.08em;text-transform:uppercase;margin-bottom:14px}
.site-footer a{color:#94a2ab}
.site-footer a:hover{color:#fff}
.foot-grid{display:grid;grid-template-columns:1.6fr 1fr 1fr 1.2fr;gap:32px}
.foot-grid ul{list-style:none;padding:0;margin:0}
.foot-grid li{margin:7px 0}
.foot-bottom{border-top:1px solid #1d252b;margin-top:36px;padding-top:18px;font-size:13px;color:#6c7a83;display:flex;justify-content:space-between;gap:14px;flex-wrap:wrap}
.contact-list{list-style:none;padding:0;margin:0}
.contact-list li{margin:9px 0;color:#94a2ab}
.contact-list b{color:#dfe6ea;font-weight:600}

/* ---------- form ---------- */
.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.field{display:flex;flex-direction:column}
.field.full{grid-column:1/-1}
label{font-size:13.5px;font-weight:700;margin-bottom:6px;color:var(--ink-2)}
input,select,textarea{
  font:inherit;font-size:15px;padding:11px 13px;border:1px solid var(--line);
  border-radius:6px;background:#fff;color:var(--ink);width:100%;
}
input:focus,select:focus,textarea:focus{outline:2px solid var(--accent);outline-offset:-1px;border-color:var(--accent)}
textarea{min-height:110px;resize:vertical}
.form-note{font-size:13px;color:var(--muted);margin-top:10px}

/* ---------- responsive ---------- */
@media (max-width:1000px){
  .g4{grid-template-columns:repeat(2,1fr)}
  .g3{grid-template-columns:repeat(2,1fr)}
  .split{grid-template-columns:1fr;gap:28px}
  .foot-grid{grid-template-columns:1fr 1fr}
  .hero-facts{grid-template-columns:repeat(2,1fr)}
}
@media (max-width:760px){
  .nav-toggle{
    display:block;background:none;border:1px solid var(--line);border-radius:6px;
    font-size:18px;line-height:1;padding:8px 12px;color:var(--ink);cursor:pointer;
  }
  .site-header .wrap{position:relative;height:64px}
  .nav{
    display:none;position:absolute;top:100%;left:0;right:0;background:#fff;
    border-bottom:1px solid var(--line);box-shadow:var(--shadow-lg);
    flex-direction:column;align-items:stretch;gap:0;padding:8px 0;
  }
  .nav.open{display:flex}
  .nav a{padding:12px 24px}
  .nav .has-menu{display:contents}
  .nav .has-menu>a{color:var(--muted);font-size:13px;text-transform:uppercase;letter-spacing:.06em;padding-top:16px}
  .nav .has-menu>a::after{display:none}
  .nav .sub{display:block;position:static;box-shadow:none;border:none;min-width:0;padding:0}
  .nav .sub a{padding:10px 24px 10px 36px}
  .g2,.g3,.g4{grid-template-columns:1fr}
  .foot-grid{grid-template-columns:1fr}
  .form-grid{grid-template-columns:1fr}
  .header-cta{display:none}
  .brand{min-width:0;flex:1}
  .brand-name small{display:none}
  .brand img{height:32px}
  .brand-name{font-size:19px}
  .section{padding:52px 0}
  .hero .wrap{padding-top:64px;padding-bottom:60px}
  .header-cta .btn-ghost{display:none}
}