/* ============================================================
   XUNBO MECH — European Industrial Design System
   Palette: graphite anthracite, industrial blue (#004388),
   warm neutrals, hairline borders, technical sans-serif.
   ============================================================ */

:root{
  --content-max:1280px;
  --ink:#15181c;          /* near-black graphite, primary text */
  --graphite:#22272d;     /* dark section backgrounds */
  --anthracite:#2b3138;   /* secondary dark */
  --steel:#004388;        /* primary industrial blue accent */
  --steel-dark:#002f5e;   /* hover / deep blue */
  --steel-soft:#0a5b9e;   /* lighter link blue */
  --paper:#fbfbfa;        /* warm off-white */
  --mist:#f3f4f6;         /* neutral section background */
  --line:#d4d8de;         /* hairline border */
  --line-soft:#e6e8ec;    /* lighter hairline */
  --slate:#5c636b;        /* muted secondary text */
  --slate-light:#8a9099;  /* tertiary text */
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:"Helvetica Neue","Inter","Segoe UI",Arial,sans-serif;
  color:var(--ink);
  background:var(--paper);
  line-height:1.6;
  font-size:15px;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
img{max-width:100%}

/* ---- Header / Navigation ---- */
.site-header{
  height:72px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  padding:0 max(48px,calc((100vw - var(--content-max))/2));
  border-bottom:1px solid var(--line);
  position:sticky;
  top:0;
  background:rgba(251,251,250,.97);
  backdrop-filter:blur(10px);
  z-index:100;
}
.brand{display:flex;align-items:center;gap:14px;text-decoration:none}
.brand-logo{width:40px;height:44px;object-fit:contain;background:transparent;display:block;flex-shrink:0;filter:drop-shadow(0 1px 2px rgba(0,0,0,.08))}
.brand-text{
  display:inline-block;
  font-size:20px;
  font-weight:800;
  letter-spacing:1.2px;
  color:var(--graphite);
  white-space:nowrap;
  line-height:1.05;
  font-family:"Helvetica Neue","Inter","Segoe UI",Arial,sans-serif;
  text-align:justify;
  text-align-last:justify;
}
.brand-text span{
  display:block;
  font-size:10px;
  font-weight:700;
  letter-spacing:2.5px;
  color:var(--steel);
  text-transform:uppercase;
  margin-top:4px;
  text-align:justify;
  text-align-last:justify;
}
.nav{display:flex;gap:30px;align-items:center}
.nav a{
  color:var(--ink);
  text-decoration:none;
  font-weight:600;
  font-size:15px;
  letter-spacing:.2px;
  padding:25px 0 22px;
  border-bottom:2px solid transparent;
  white-space:nowrap;
  transition:color .15s,border-color .15s;
}
.nav a:hover,.nav a.active{color:var(--steel);border-color:var(--steel)}
.menu-btn{display:none;background:none;border:0;font-size:26px;cursor:pointer;color:var(--ink)}

/* ---- Page hero ---- */
.page-hero{
  max-width:var(--content-max);
  margin:0 auto;
  padding:68px 0 40px;
  min-height:300px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:42px;
  overflow:hidden;
}
.page-hero-copy{max-width:780px}
.eyebrow{
  font-size:11px;
  letter-spacing:2px;
  font-weight:800;
  color:var(--steel);
  text-transform:uppercase;
}
.page-hero h1{
  font-size:clamp(40px,4vw,56px);
  line-height:1.05;
  letter-spacing:-1.5px;
  margin:12px 0 14px;
  font-weight:700;
}
.lead{
  font-size:16px;
  line-height:1.55;
  color:var(--slate);
  margin:0 0 24px;
  max-width:820px;
}
.page-hero-visual{width:40%;min-width:300px;text-align:center}
.page-hero-visual img{max-height:250px;width:auto;object-fit:contain;opacity:.82}

/* ---- Sections ---- */
.section{
  max-width:var(--content-max);
  margin:0 auto;
  padding:64px 0;
  position:relative;
}
.section + .section{border-top:1px solid var(--line-soft)}
.section-head{max-width:880px;margin-bottom:34px}
.section h2,.dark-section h2,.about h2{
  font-size:clamp(28px,2.7vw,38px);
  line-height:1.1;
  letter-spacing:-1px;
  margin:8px 0 16px;
  font-weight:700;
}
.section-head p{font-size:15px;line-height:1.65;color:var(--slate);max-width:820px}

/* ---- Capability grid / cards ---- */
.cap-grid{
  display:grid;
  grid-template-columns:repeat(3,1fr);
  border-top:1px solid var(--line);
  border-left:1px solid var(--line);
}
.card{
  padding:30px 32px;
  min-height:210px;
  border-right:1px solid var(--line);
  border-bottom:1px solid var(--line);
  background:var(--paper);
  transition:background .15s;
}
.card:hover{background:#fff}
.card-highlight{background:#eef3f9}
.number{color:var(--steel);font-weight:800;font-size:13px;letter-spacing:1px}
.card h3{font-size:21px;line-height:1.15;margin:26px 0 12px;font-weight:700;letter-spacing:-.3px}
.card p{font-size:14px;line-height:1.65;color:var(--slate);margin-bottom:0}

/* ---- Feature strip (shared) ---- */
.feature-strip{
  display:grid;
  grid-template-columns:repeat(4,1fr);
  background:var(--steel);
  color:#fff;
}
.feature-strip div{
  text-align:center;
  padding:18px 14px;
  font-size:14px;
  line-height:1.35;
  font-weight:700;
  border-right:1px solid rgba(255,255,255,.28);
}
.feature-strip div:last-child{border:0}

/* ---- Dark section (technology) ---- */
.dark-section{
  background:var(--graphite);
  color:#fff;
  padding:62px max(48px,calc((100vw - var(--content-max))/2));
}
.dark-section .eyebrow{color:#7fa8d6}
.dark-section .lead{color:#c8ccd2}
.tech-layout{
  max-width:var(--content-max);
  margin:0 auto;
  display:grid;
  grid-template-columns:1fr .9fr;
  gap:50px;
  align-items:center;
}
.tech-points{
  display:grid;
  grid-template-columns:1fr 1fr;
  margin-top:34px;
  border-top:1px solid #44495100;
}
.tech-points{
  border-top:1px solid #41464d;
}
.tech-points div{padding:22px 18px 22px 0;border-bottom:1px solid #41464d}
.tech-points b{display:block;font-size:18px;color:#fff;margin-bottom:6px}
.tech-points span{color:#b8bcc4;font-size:14px;line-height:1.5}
.tech-image{
  display:flex;
  align-items:center;
  justify-content:center;
  min-height:340px;
  background:#2b3138;
  border:1px solid #3a4047;
  padding:24px;
}
.tech-image img{width:auto;max-width:100%;max-height:420px;height:auto;object-fit:contain;display:block}

/* ---- Application grid ---- */
.application-grid{
  display:grid;
  grid-template-columns:repeat(4,1fr);
  border-top:1px solid var(--line);
  border-left:1px solid var(--line);
}
.application-grid article{
  padding:24px;
  border-right:1px solid var(--line);
  border-bottom:1px solid var(--line);
  min-height:155px;
  transition:background .15s;
}
.application-grid article:hover{background:#fff}
.application-grid h3{margin:0 0 12px;font-size:19px;line-height:1.25;font-weight:700}
.application-grid p{margin:0;font-size:15px;line-height:1.6;color:var(--slate)}

/* ---- Material bar ---- */
.material-bar{
  max-width:var(--content-max);
  margin:34px auto 0;
  background:var(--steel);
  color:#fff;
  display:grid;
  grid-template-columns:1fr 1.5fr;
}
.material-bar div{padding:22px 30px;border-right:1px solid rgba(255,255,255,.3)}
.material-bar div:last-child{border-right:0}
.material-bar small{display:block;opacity:.85;margin-bottom:4px;font-size:12px;letter-spacing:1px;text-transform:uppercase}
.material-bar strong{font-size:17px;line-height:1.4;font-weight:600}

/* ---- About (shared components) ---- */
.about{display:grid;grid-template-columns:1fr 1fr;background:var(--graphite);color:#fff}
.about-copy{padding:82px 8vw}
.about .eyebrow{color:#7fa8d6}
.about-copy>p{font-size:17px;line-height:1.7;color:#d2d6dc;max-width:720px}
.about-facts{display:grid;grid-template-columns:1fr 1fr;margin-top:42px;border-top:1px solid #41464d}
.about-facts div{padding:20px 18px 20px 0;border-bottom:1px solid #41464d}
.about-facts small{display:block;color:#9ba2ab;margin-bottom:5px;font-size:12px;letter-spacing:.5px}
.about-facts b{font-size:17px;font-weight:600}
.about-image{display:flex;align-items:center;justify-content:center;background:var(--mist);min-height:520px;padding:30px}
.about-image img{width:auto;max-width:100%;height:auto;max-height:100%;object-fit:contain;display:block}

/* ---- Contact components ---- */
.contact-intro{
  max-width:var(--content-max);
  margin:0 auto;
  padding:54px 0 24px;
  position:relative;
  overflow:hidden;
}
.contact-intro .page-hero-copy{position:relative;z-index:2}
.contact-sketch-hero{position:absolute;right:6%;top:0;width:43%;max-height:300px;object-fit:contain;opacity:.4;mix-blend-mode:multiply}
.contact-grid{
  max-width:var(--content-max);
  margin:0 auto;
  display:grid;
  grid-template-columns:1.05fr .95fr;
  gap:26px;
  padding:24px 0 50px;
}
.contact-form,.contact-card{
  border:1px solid var(--line);
  padding:28px;
  background:var(--paper);
}
.contact-form label{display:block;font-size:14px;color:var(--slate);margin-bottom:20px}
.contact-form input,.contact-form select,.contact-form textarea{
  display:block;width:100%;margin-top:8px;border:0;border-bottom:1px solid var(--line);
  padding:10px 0;font:inherit;font-size:15px;line-height:1.5;background:transparent;outline:none;
}
.contact-form textarea{min-height:90px;resize:vertical}
.contact-form input:focus,.contact-form select:focus,.contact-form textarea:focus{border-color:var(--steel)}
.two-col{display:grid;grid-template-columns:1fr 1fr;gap:28px}
.contact-card h3{font-size:22px;margin:4px 0 14px;font-weight:700}
.contact-card p{font-size:14px;line-height:1.65;color:var(--slate)}
.contact-card hr{border:0;border-top:1px solid var(--line);margin:22px 0}
.contact-links{display:flex;justify-content:space-between;gap:15px}
.contact-links a{color:var(--ink)}
.form-note{min-height:18px;color:var(--steel);margin:12px 0 0!important;font-size:13px!important}
.contact-benefits{
  max-width:var(--content-max);
  margin:0 auto 50px;
  display:grid;
  grid-template-columns:repeat(3,1fr);
  border:1px solid var(--line);
}
.benefit{padding:24px 30px;border-right:1px solid var(--line);background:var(--paper)}
.benefit:last-child{border-right:0}
.benefit h3{margin:0 0 9px;font-size:18px;font-weight:700}
.benefit p{margin:0;font-size:14px;line-height:1.6;color:var(--slate)}

/* ---- Page image wrap ---- */
.page-image-wrap{max-width:var(--content-max);margin:0 auto;padding:30px 0 68px}
.page-image-wrap img{display:block;width:100%;height:auto;object-fit:contain}

/* ---- CTA ---- */
.cta{
  max-width:var(--content-max);
  margin:0 auto 58px;
  background:var(--steel);
  color:#fff;
  padding:28px 34px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:24px;
}
.cta h3{margin:0 0 6px;font-size:20px;font-weight:700}
.cta p{margin:0;color:#d6e2f0;font-size:14px}

/* ---- Buttons ---- */
.actions{display:flex;gap:12px;flex-wrap:wrap}
.btn{
  display:inline-flex;align-items:center;justify-content:center;
  border-radius:4px;padding:11px 22px;text-decoration:none;font-weight:600;
  border:1px solid var(--steel);cursor:pointer;font-size:14px;letter-spacing:.3px;
  transition:background .15s,color .15s;
  white-space:nowrap;
}
.btn-primary{background:var(--steel);color:#fff}
.btn-primary:hover{background:var(--steel-dark)}
.btn-outline{background:transparent;color:var(--steel)}
.btn-outline:hover{background:var(--steel);color:#fff}

/* ---- Footer ---- */
footer{
  background:var(--graphite);
  color:#c2c6cc;
  padding:34px max(48px,calc((100vw - var(--content-max))/2));
  border-top:1px solid #3a4047;
}
.footer-grid{
  max-width:var(--content-max);
  margin:0 auto;
  display:grid;
  grid-template-columns:1.2fr .8fr 1fr .7fr;
  gap:38px;
}
.footer-brand{display:flex;align-items:center;gap:12px;margin-bottom:14px}
.footer-brand .brand-logo{width:34px;height:38px;filter:brightness(0) invert(1)}
.footer-brand-text{
  display:inline-block;
  font-size:17px;
  font-weight:800;
  color:#fff;
  letter-spacing:1px;
  line-height:1.05;
  text-align:justify;
  text-align-last:justify;
}
.footer-brand-text span{
  display:block;
  font-size:9px;
  font-weight:700;
  letter-spacing:2px;
  color:#9ba2ab;
  text-transform:uppercase;
  margin-top:3px;
  text-align:justify;
  text-align-last:justify;
}
.footer-title{font-weight:700;color:#fff;margin-bottom:12px;font-size:14px;letter-spacing:.5px;text-transform:uppercase;white-space:nowrap}
.footer-links{display:flex;flex-direction:column;gap:7px}
.footer-links a{color:#c2c6cc;text-decoration:none;font-size:14px}
.footer-links a:hover{color:#fff}
.footer-bottom{
  margin-top:28px;padding-top:18px;
  border-top:1px solid #3a4047;
  display:flex;justify-content:space-between;gap:20px;
  font-size:13px;line-height:1.5;color:#9ba2ab;
}

/* ---- Brand transparency ---- */
.brand,.brand-logo,.logo,.site-logo,.header-logo{background:transparent!important;box-shadow:none!important}
.brand img,.brand-logo img,.logo img,.site-logo img,.header-logo img{background:transparent!important;box-shadow:none!important;object-fit:contain}

/* ---- Responsive ---- */
@media(max-width:900px){
  .site-header{height:66px;padding-left:24px;padding-right:24px}
  .brand-logo{width:34px;height:38px}
  .brand-text{font-size:17px;letter-spacing:1px}
  .brand-text span{font-size:9px;letter-spacing:2px}
  .menu-btn{display:block}
  .nav{display:none;position:absolute;left:0;right:0;top:66px;background:var(--paper);padding:10px 24px 18px;flex-direction:column;align-items:flex-start;gap:0;border-bottom:1px solid var(--line);box-shadow:0 8px 24px rgba(0,0,0,.08)}
  .nav.open{display:flex}
  .nav a{padding:12px 0}
  .page-hero{display:block;padding:48px 24px 40px}
  .page-hero-visual{width:100%;min-width:0;margin-top:32px}
  .cap-grid,.application-grid{grid-template-columns:1fr 1fr}
  .tech-layout,.about,.contact-grid{grid-template-columns:1fr}
  .about-copy{padding:60px 24px}
  .feature-strip{grid-template-columns:1fr 1fr}
  .material-bar{grid-template-columns:1fr}
  .contact-benefits{grid-template-columns:1fr}
  .benefit{border-right:0;border-bottom:1px solid var(--line)}
  .benefit:last-child{border-bottom:0}
  .footer-grid{grid-template-columns:1fr 1fr}
  .contact-sketch-hero{width:50%;right:0}
  .cta{flex-direction:column;align-items:flex-start}
}
@media(max-width:600px){
  .site-header{height:62px}
  .brand-logo{width:32px;height:36px}
  .brand-text{font-size:16px;letter-spacing:.8px}
  .brand-text span{font-size:8px;letter-spacing:1.8px}
  .nav{top:62px}
  .page-hero h1{font-size:36px;letter-spacing:-1px}
  .lead{font-size:15px}
  .cap-grid,.application-grid,.two-col,.footer-grid{grid-template-columns:1fr}
  .feature-strip{grid-template-columns:1fr}
  .feature-strip div{border-right:0;border-bottom:1px solid rgba(255,255,255,.22)}
  .tech-points{grid-template-columns:1fr}
  .card{min-height:auto}
  .contact-card{padding:22px}
  .contact-intro{padding:42px 24px 18px}
  .contact-grid{padding:18px 24px 36px}
  .contact-sketch-hero{position:relative;width:100%;right:auto;top:auto;margin-top:10px;max-height:200px}
  .footer-bottom{flex-direction:column}
  .section{padding:50px 24px}
  .page-image-wrap{padding:20px 24px 46px}
}