/* Overhead Conveyor Chain Co. — 参数规格风 spec-sheet · P-02 深蓝专业 · F-02 */
:root{
  --primary:#1E3A5F; --secondary:#3B82A6; --accent:#F59E0B;
  --text:#1F2937; --muted:#6B7280; --bg:#F8FAFC; --surface:#fff;
  --dark:#111C2B; --line:#D8E0EA;
  --ease:cubic-bezier(.22,.61,.21,1);
  --container:min(1280px,94vw);
  --section:clamp(56px,7vw,104px);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:'Inter',system-ui,-apple-system,sans-serif;color:var(--text);background:var(--bg);line-height:1.65;font-size:16px}
h1,h2,h3,h4{font-family:'Archivo','Arial Narrow',sans-serif;line-height:1.25;color:var(--primary);letter-spacing:-.01em}
.mono{font-family:'IBM Plex Mono',ui-monospace,monospace}
img{max-width:100%;height:auto;display:block}
a{color:var(--secondary)}
.container{width:var(--container);margin:0 auto}
/* ---------- header ---------- */
.site-header{background:var(--primary);color:#fff;position:sticky;top:0;z-index:50}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:68px;width:var(--container);margin:0 auto}
.brand{color:#fff;text-decoration:none;font-family:'Archivo',sans-serif;font-weight:800;font-size:19px;letter-spacing:.02em}
.brand small{display:block;font-size:11px;font-weight:400;color:#B9C6D6;letter-spacing:.08em}
.main-nav{display:flex;gap:4px;align-items:center}
.main-nav a,.main-nav .nav-drop>button{color:#E6EDF5;text-decoration:none;padding:10px 12px;font-size:14.5px;background:none;border:0;cursor:pointer;font-family:inherit}
.main-nav a:hover,.main-nav .nav-drop>button:hover{color:var(--accent)}
.nav-drop{position:relative}
.nav-drop .drop-menu{position:absolute;top:100%;left:0;background:#fff;min-width:250px;box-shadow:0 12px 32px rgba(17,28,43,.25);border-radius:6px;padding:8px;display:none}
.nav-drop:hover .drop-menu,.nav-drop:focus-within .drop-menu{display:block}
.nav-drop .drop-menu a{display:block;color:var(--text);padding:9px 12px;border-radius:4px}
.nav-drop .drop-menu a:hover{background:var(--bg);color:var(--primary)}
.header-cta{background:var(--accent);color:#1F2937!important;font-weight:700;border-radius:4px;padding:10px 18px!important;text-decoration:none;font-size:14.5px}
/* .nav-toggle 只在 max-width 媒体查询内定义；桌面端靠 hidden 属性隐藏 */
/* ---------- hero ---------- */
.hero{background:linear-gradient(135deg,var(--dark) 0%,var(--primary) 100%);color:#fff;padding:clamp(48px,6vw,88px) 0}
.hero h1{color:#fff;font-size:clamp(30px,4.4vw,52px);max-width:20ch}
.hero p.lead{color:#C9D6E5;font-size:18px;max-width:62ch;margin-top:14px}
.hero .kicker{color:var(--accent);font-weight:700;letter-spacing:.14em;font-size:13px;text-transform:uppercase}
/* spec-strip 签名组件 */
.spec-strip{display:grid;grid-template-columns:repeat(4,1fr);gap:2px;background:var(--line);border:1px solid var(--line);border-radius:8px;overflow:hidden;margin-top:32px}
.spec-cell{background:var(--surface);padding:20px 22px}
.spec-cell .m{font-family:'IBM Plex Mono',monospace;font-weight:700;font-size:22px;color:var(--primary)}
.spec-cell .k{font-size:12px;color:var(--muted);text-transform:uppercase;letter-spacing:.08em;margin-top:2px}
.spec-cell .v{font-size:14px;margin-top:6px;color:var(--text)}
/* ---------- sections ---------- */
.section{padding:var(--section) 0}
.section h2{font-size:clamp(24px,3vw,34px);margin-bottom:8px}
.section .sub{color:var(--muted);max-width:70ch;margin-bottom:32px}
.split{display:grid;grid-template-columns:2fr 1fr;gap:40px;align-items:start}
.split>*{min-width:0}
/* spec-table */
.table-wrap{overflow-x:auto;max-width:100%;border:1px solid var(--line);border-radius:8px;background:#fff}
table.spec{width:100%;border-collapse:collapse;font-size:14.5px;min-width:640px}
table.spec th{background:var(--primary);color:#fff;text-align:left;padding:12px 16px;font-weight:600;white-space:nowrap}
table.spec td{padding:12px 16px;border-top:1px solid var(--line);vertical-align:top}
table.spec tr:nth-child(even) td{background:#F2F6FA}
table.spec td.num{font-family:'IBM Plex Mono',monospace;white-space:nowrap}
/* limit-card 边界声明 */
.limit-card{border-left:4px solid var(--accent);background:#FFFBEB;padding:18px 22px;border-radius:0 8px 8px 0;margin:18px 0}
.limit-card strong{color:var(--primary)}
/* category grid */
.cat-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.cat-card{background:#fff;border:1px solid var(--line);border-radius:8px;padding:26px;text-decoration:none;color:var(--text);display:block}
.cat-card h3{font-size:19px;margin-bottom:8px}
.cat-card p{font-size:14.5px;color:var(--muted)}
.cat-card .go{color:var(--accent);font-weight:700;font-size:14px;margin-top:10px;display:inline-block}
/* industry grid */
.ind-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:16px}
.ind-card{background:#fff;border:1px solid var(--line);border-radius:8px;overflow:hidden}
.ind-card img{aspect-ratio:4/3;object-fit:cover;width:100%}
.ind-card .t{padding:14px 16px}
.ind-card .t h3{font-size:16px;margin-bottom:4px}
.ind-card .t p{font-size:13.5px;color:var(--muted)}
/* quote card 侧栏 */
.quote-card{background:var(--primary);color:#fff;border-radius:8px;padding:28px;position:sticky;top:96px}
.quote-card h3{color:#fff;margin-bottom:6px}
.quote-card p{font-size:14px;color:#C9D6E5;margin-bottom:16px}
.quote-card .btn{display:block;text-align:center;background:var(--accent);color:#1F2937;font-weight:700;padding:12px;border-radius:4px;text-decoration:none}
.cert-badges{display:flex;gap:10px;flex-wrap:wrap;margin-top:14px}
.cert-badges span{border:1px solid #3B5878;color:#C9D6E5;font-size:12.5px;padding:6px 12px;border-radius:999px}
/* evidence strip */
.evidence{background:var(--dark);color:#fff}
.evidence .e-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px;text-align:center}
.evidence .n{font-family:'IBM Plex Mono',monospace;font-size:34px;font-weight:700;color:var(--accent)}
.evidence .l{font-size:13.5px;color:#B9C6D6;margin-top:4px}
/* CTA */
.cta-band{background:linear-gradient(120deg,var(--primary),#274b78);color:#fff;border-radius:12px;padding:clamp(32px,5vw,56px);display:grid;grid-template-columns:2fr 1fr;gap:32px;align-items:center}
.cta-band h2{color:#fff}
.cta-band p{color:#C9D6E5}
/* buttons */
.btn{display:inline-block;background:var(--accent);color:#1F2937;font-weight:700;padding:13px 28px;border-radius:4px;text-decoration:none;border:0;cursor:pointer;font-size:16px}
.btn-ghost{display:inline-block;border:2px solid var(--primary);color:var(--primary);font-weight:700;padding:11px 26px;border-radius:4px;text-decoration:none}
/* forms */
.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.form-grid .full{grid-column:1/-1}
label.f{display:block;font-size:14px;font-weight:600;margin-bottom:14px}
label.f input,label.f textarea,label.f select{width:100%;margin-top:6px;padding:11px 13px;border:1px solid var(--line);border-radius:4px;font-size:15px;font-family:inherit}
label.f input:focus,label.f textarea:focus{outline:2px solid var(--secondary);border-color:var(--secondary)}
.honeypot{position:absolute;left:-9999px;top:auto;width:1px;height:1px;overflow:hidden}
/* prose / article */
.prose-layout{display:grid;grid-template-columns:minmax(0,1fr) 320px;gap:48px;align-items:start}
.prose-layout>*{min-width:0}
.prose{font-size:16.5px;max-width:68ch}
.prose h2{margin:34px 0 12px;font-size:24px}
.prose h3{margin:26px 0 10px;font-size:19px}
.prose p{margin-bottom:16px}
.prose ul{margin:0 0 16px 22px}
.prose li{margin-bottom:8px}
.spec-sidebar{background:#fff;border:1px solid var(--line);border-radius:8px;padding:22px;position:sticky;top:96px}
.spec-sidebar h3{font-size:16px;margin-bottom:10px;color:var(--primary)}
.spec-sidebar dl{font-size:13.5px}
.spec-sidebar dt{font-weight:700;color:var(--muted);font-size:12px;text-transform:uppercase;letter-spacing:.06em;margin-top:10px}
.spec-sidebar dd{margin:2px 0 0;font-family:'IBM Plex Mono',monospace}
/* footer */
.site-footer{background:var(--dark);color:#B9C6D6;padding:56px 0 28px;margin-top:0}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:32px;margin-bottom:36px}
.site-footer h4{color:#fff;font-size:15px;margin-bottom:12px}
.site-footer a{color:#B9C6D6;text-decoration:none;font-size:14px;display:block;margin-bottom:8px}
.site-footer a:hover{color:var(--accent)}
.footer-bottom{border-top:1px solid #24344a;padding-top:20px;font-size:13px;display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap}
/* breadcrumb */
.crumbs{font-size:13.5px;color:var(--muted);padding:18px 0 0}
.crumbs a{color:var(--secondary);text-decoration:none}
/* reveal */
.reveal{opacity:0;transform:translateY(22px);transition:opacity .6s var(--ease),transform .6s var(--ease)}
.reveal.is-visible{opacity:1;transform:none}
html.no-js .reveal{opacity:1;transform:none}
/* responsive */
@media (max-width:1080px){
  .ind-grid{grid-template-columns:repeat(3,1fr)}
  .cat-grid{grid-template-columns:repeat(2,1fr)}
  .evidence .e-grid{grid-template-columns:repeat(2,1fr)}
}
@media (max-width:1100px){
  .hero-grid{grid-template-columns:1fr!important}
  .main-nav{display:none;position:absolute;top:68px;left:0;right:0;background:var(--primary);flex-direction:column;align-items:stretch;padding:12px 5vw 20px}
  .main-nav.open{display:flex}
  .nav-drop .drop-menu{position:static;box-shadow:none;background:transparent;display:block;padding:0 0 0 12px}
  .nav-drop .drop-menu a{color:#E6EDF5}
  .nav-toggle{display:block;background:none;border:1px solid #3B5878;border-radius:4px;color:#fff;font-size:20px;padding:6px 12px;cursor:pointer}
  .header-cta{display:none}
  .spec-strip{grid-template-columns:repeat(2,1fr)}
  .split,.prose-layout,.cta-band{grid-template-columns:1fr}
  .quote-card,.spec-sidebar{position:static}
  .cat-grid{grid-template-columns:1fr}
  .ind-grid{grid-template-columns:repeat(2,1fr)}
  .footer-grid{grid-template-columns:1fr 1fr}
  .form-grid{grid-template-columns:1fr}
}
@media (hover: hover){
  .btn:hover{filter:brightness(1.06)}
  .cat-card:hover{border-color:var(--secondary);box-shadow:0 8px 24px rgba(30,58,95,.12)}
  a:hover{text-decoration:underline}
  .main-nav a:hover,.header-cta:hover{text-decoration:none}
}
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.01ms!important;transition-duration:.01ms!important}
  html{scroll-behavior:auto}
  .reveal{opacity:1;transform:none}
}
a:active,.btn:active{transform:scale(.98)}
:focus-visible{outline:3px solid var(--accent);outline-offset:2px}