:root {
  --navy: #071a2f;
  --navy-deep: #04111f;
  --paper: #f4f2ec;
  --white: #fffefa;
  --ink: #102236;
  --muted: #62707c;
  --steel: #88939f;
  --line: rgba(16, 34, 54, 0.2);
  --line-light: rgba(255, 255, 255, 0.2);
  --copper: #b86135;
  --copper-dark: #8f3e1f;
  --max: 1440px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 88px; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: "Microsoft YaHei", "Noto Sans SC", Arial, sans-serif; line-height: 1.65; overflow-x: hidden; }
img { display: block; max-width: 100%; }
a { color: inherit; }
button, input, textarea { font: inherit; }
button, a, input, textarea { -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 3px solid #e07b49; outline-offset: 4px; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.skip-link { position: fixed; left: 16px; top: -80px; z-index: 100; padding: 12px 18px; background: var(--white); color: var(--navy); }
.skip-link:focus { top: 12px; }

.site-header { height: 84px; padding: 0 clamp(20px, 4vw, 68px); display: flex; align-items: center; justify-content: space-between; position: absolute; inset: 0 0 auto; z-index: 20; color: var(--white); border-bottom: 1px solid rgba(255,255,255,.16); }
.brand { display: inline-flex; align-items: center; gap: 12px; text-decoration: none; min-height: 48px; }
.brand-mark { width: 44px; height: 44px; flex: none; fill: none; stroke: currentColor; stroke-width: 2; }
.brand-mark .brand-route, .brand-mark circle { stroke: var(--copper); }
.brand span { display: grid; gap: 1px; }
.brand strong { font-size: 17px; letter-spacing: .08em; }
.brand small { font-size: 9px; letter-spacing: .15em; opacity: .72; }
.primary-nav { display: flex; align-items: center; gap: clamp(20px, 2.6vw, 42px); }
.primary-nav a { min-height: 44px; display: inline-flex; align-items: center; font-size: 14px; text-decoration: none; }
.primary-nav a:hover { color: #f0a57e; }
.primary-nav a:focus { outline: 3px solid #e07b49; outline-offset: 3px; }
.primary-nav .nav-contact { padding: 0 20px; border: 1px solid rgba(255,255,255,.42); }
.menu-toggle { display: none; width: 48px; height: 48px; padding: 0; border: 0; color: inherit; background: transparent; position: relative; }
.menu-toggle > span:not(.sr-only) { position: absolute; left: 11px; width: 26px; height: 1px; background: currentColor; transition: transform .2s ease, top .2s ease; }
.menu-toggle > span:nth-child(2) { top: 19px; }
.menu-toggle > span:nth-child(3) { top: 29px; }

.hero { min-height: min(900px, 100svh); position: relative; display: flex; align-items: center; color: var(--white); background: var(--navy-deep); isolation: isolate; overflow: hidden; }
.hero-image, .hero-shade { position: absolute; inset: 0; width: 100%; height: 100%; }
.hero-image { object-fit: cover; object-position: center; z-index: -3; }
.hero-shade { z-index: -2; background: linear-gradient(90deg, rgba(4,17,31,.96) 0%, rgba(4,17,31,.82) 38%, rgba(4,17,31,.24) 68%, rgba(4,17,31,.08) 100%), linear-gradient(0deg, rgba(4,17,31,.5), transparent 45%); }
.hero::after { content: ""; position: absolute; z-index: -1; left: 0; bottom: 76px; width: 58%; height: 1px; background: linear-gradient(90deg, transparent 0 8%, var(--copper) 8% 84%, transparent); }
.hero-content { width: min(92%, var(--max)); margin: 84px auto 0; padding: 80px clamp(0px, 3vw, 48px); }
.eyebrow { margin: 0 0 26px; color: #d8926d; font-size: 12px; font-weight: 700; letter-spacing: .18em; }
.hero h1 { max-width: 1020px; margin: 0; font-size: clamp(52px, 7.2vw, 112px); line-height: 1.05; letter-spacing: -.055em; font-weight: 600; }
.hero-lead { max-width: 610px; margin: 30px 0 0; font-size: clamp(17px, 1.5vw, 22px); color: rgba(255,255,255,.78); }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; margin-top: 40px; }
.button { min-height: 50px; padding: 0 24px; display: inline-flex; align-items: center; justify-content: center; border: 1px solid transparent; border-radius: 0; text-decoration: none; font-weight: 700; cursor: pointer; }
.button-primary { color: var(--white); background: var(--copper-dark); border-color: var(--copper-dark); }
.button-primary:hover { background: #743117; border-color: #743117; }
.button-ghost { color: var(--white); border-color: rgba(255,255,255,.5); background: rgba(7,26,47,.18); }
.button-ghost:hover { background: rgba(255,255,255,.1); }
.hero-index { position: absolute; right: clamp(22px, 4vw, 68px); bottom: 54px; display: flex; gap: 160px; font: 600 12px/1 Arial, sans-serif; color: rgba(255,255,255,.65); }

.section-label { font-size: 12px; font-weight: 700; letter-spacing: .14em; text-transform: uppercase; color: var(--muted); }
.section-label span { color: var(--copper-dark); margin-right: 14px; }
.section-label-light { color: rgba(255,255,255,.6); }
.section-label-light span { color: #dc8e64; }
.opening { max-width: var(--max); margin: auto; padding: clamp(82px, 10vw, 150px) clamp(24px, 5vw, 72px); display: grid; grid-template-columns: .72fr 1.55fr .95fr; gap: clamp(30px, 5vw, 84px); align-items: start; }
.opening h2, .materials h2, .route h2, .applications h2, .contact h2 { margin: 0; font-size: clamp(38px, 5vw, 76px); line-height: 1.12; letter-spacing: -.045em; font-weight: 600; }
.opening-copy p, .materials-intro p { max-width: 690px; margin: 28px 0 0; color: #465665; font-size: 17px; }
.opening-facts { margin: 0; border-top: 1px solid var(--line); }
.opening-facts div { padding: 18px 0; border-bottom: 1px solid var(--line); }
.opening-facts dt { margin-bottom: 5px; font-size: 12px; color: var(--muted); }
.opening-facts dd { margin: 0; font-size: 16px; font-weight: 700; }

.route { background: var(--navy); color: var(--white); padding: clamp(80px, 9vw, 140px) 0; }
.route-heading { width: min(calc(100% - 48px), var(--max)); margin: 0 auto clamp(60px, 8vw, 112px); display: grid; grid-template-columns: .75fr 2fr; gap: 60px; padding: 0 clamp(0px, 3vw, 44px); }
.route-heading > div:last-child { display: grid; grid-template-columns: 1.35fr .75fr; gap: 54px; align-items: end; }
.route-heading p { margin: 0; color: rgba(255,255,255,.64); font-size: 16px; }
.route-list { width: min(calc(100% - 48px), var(--max)); margin: auto; position: relative; }
.route-list::before { content: ""; position: absolute; left: 38px; top: 0; bottom: 0; width: 1px; background: linear-gradient(var(--copper), rgba(184,97,53,.22)); }
.route-step { display: grid; grid-template-columns: 78px minmax(240px,.75fr) minmax(400px,1.5fr); gap: clamp(28px, 4vw, 64px); align-items: center; min-height: 480px; padding: 48px 0; border-top: 1px solid var(--line-light); }
.route-step:last-child { border-bottom: 1px solid var(--line-light); }
.route-step-reverse .step-copy { order: 3; }
.route-step-reverse figure { order: 2; }
.route-step-reverse .step-number { order: 1; }
.step-number { align-self: stretch; position: relative; display: flex; justify-content: center; padding-top: 12px; }
.step-number span { width: 44px; height: 44px; z-index: 1; display: grid; place-items: center; border: 1px solid var(--copper); background: var(--navy); color: #f2a77f; font: 700 12px Arial, sans-serif; }
.step-copy { padding: 22px 0; }
.step-en { margin: 0 0 22px; font: 700 11px/1.3 Arial, sans-serif; letter-spacing: .17em; color: #d58c65; }
.step-copy h3 { margin: 0 0 20px; font-size: clamp(32px, 4vw, 56px); line-height: 1.1; font-weight: 600; letter-spacing: -.04em; }
.step-copy > p:last-child { max-width: 450px; margin: 0; color: rgba(255,255,255,.65); }
.route-step figure { margin: 0; height: 380px; overflow: hidden; background: var(--navy-deep); }
.route-step img { width: 100%; height: 100%; object-fit: cover; transition: transform .7s ease; }
.route-step:hover img { transform: scale(1.025); }

.materials { max-width: var(--max); margin: auto; padding: clamp(90px, 10vw, 150px) clamp(24px, 5vw, 72px); }
.materials-intro { display: grid; grid-template-columns: .7fr 2fr; gap: 60px; }
.material-lines { margin-top: clamp(70px, 8vw, 110px); border-top: 1px solid var(--line); }
.material-lines > div { min-height: 122px; display: grid; grid-template-columns: 70px .9fr 1.1fr 80px; align-items: center; gap: 24px; border-bottom: 1px solid var(--line); }
.material-lines span { color: var(--copper-dark); font: 700 12px Arial, sans-serif; }
.material-lines h3 { margin: 0; font-size: clamp(24px, 2.4vw, 36px); font-weight: 600; }
.material-lines p { margin: 0; color: var(--muted); }
.material-lines i { width: 58px; height: 10px; background: linear-gradient(90deg, #7f8991, #e8ecee, #9ca6ae); }
.material-lines > div:nth-child(3) i { background: linear-gradient(90deg, #aeb7bc, #f5f6f5, #d0d6d8); }

.applications { background: var(--navy-deep); color: var(--white); display: grid; grid-template-columns: 1.15fr .85fr; min-height: 760px; }
.application-image { min-height: 680px; }
.application-image img { width: 100%; height: 100%; object-fit: cover; }
.application-copy { padding: clamp(70px, 8vw, 126px) clamp(28px, 7vw, 110px); display: flex; flex-direction: column; justify-content: center; }
.application-copy h2 { margin-top: 32px; }
.application-copy > p { margin: 30px 0 42px; color: rgba(255,255,255,.67); }
.application-copy ul { margin: 0; padding: 0; list-style: none; border-top: 1px solid var(--line-light); }
.application-copy li { min-height: 60px; display: flex; align-items: center; gap: 24px; border-bottom: 1px solid var(--line-light); }
.application-copy li span { color: #d58c65; font: 700 11px Arial, sans-serif; }
.text-link { margin-top: 38px; align-self: flex-start; color: #f3a77f; text-underline-offset: 6px; }

.contact { max-width: var(--max); margin: auto; padding: clamp(90px, 10vw, 150px) clamp(24px, 5vw, 72px); display: grid; grid-template-columns: 1fr .8fr; gap: clamp(60px, 8vw, 130px); }
.contact-heading h2 { margin-top: 35px; font-size: clamp(42px, 5.5vw, 78px); }
.contact-details { margin-top: 54px; border-top: 1px solid var(--line); }
.contact-details a, .contact-details p { min-height: 68px; margin: 0; display: grid; grid-template-columns: 110px 1fr; align-items: center; border-bottom: 1px solid var(--line); text-decoration: none; }
.contact-details a:hover { color: var(--copper-dark); }
.contact-details span { color: var(--muted); font-size: 12px; }
.inquiry-form { align-self: start; padding-top: 46px; border-top: 2px solid var(--navy); }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.inquiry-form label { display: grid; gap: 9px; margin-bottom: 24px; color: #455463; font-size: 13px; }
.inquiry-form input, .inquiry-form textarea { width: 100%; border: 0; border-bottom: 1px solid #7d8992; border-radius: 0; padding: 11px 3px; background: transparent; color: var(--ink); }
.inquiry-form textarea { border: 1px solid #7d8992; padding: 12px; resize: vertical; min-height: 132px; }
.inquiry-form input:focus, .inquiry-form textarea:focus { border-color: var(--copper-dark); outline: 3px solid rgba(143,62,31,.22); outline-offset: 2px; }
.form-submit { width: 100%; margin-top: 4px; }
.form-status { min-height: 54px; margin: 14px 0 0; padding: 12px 14px; display: none; border-left: 3px solid var(--copper-dark); background: rgba(184,97,53,.08); color: #5b2c1b; }
.form-status.is-visible { display: block; }

.site-footer { background: var(--navy); color: var(--white); min-height: 190px; padding: 48px clamp(24px, 5vw, 72px); display: flex; justify-content: space-between; align-items: center; gap: 40px; border-top: 1px solid var(--line-light); }
.footer-brand small { max-width: 360px; }
.footer-meta { text-align: right; color: rgba(255,255,255,.58); font-size: 12px; }
.footer-meta p { margin: 4px 0; }

.reveal { opacity: 0; transform: translateY(24px); transition: opacity .7s ease, transform .7s ease; }
.reveal.is-visible { opacity: 1; transform: none; }

@media (max-width: 980px) {
  .site-header { position: absolute; height: 76px; padding-inline: 20px; }
  .menu-toggle { display: block; z-index: 3; }
  .primary-nav { position: fixed; inset: 0; padding: 110px 28px 40px; display: flex; flex-direction: column; align-items: stretch; gap: 4px; background: rgba(4,17,31,.98); transform: translateX(100%); visibility: hidden; transition: transform .25s ease, visibility .25s; }
  .primary-nav.is-open { transform: none; visibility: visible; }
  .primary-nav a { min-height: 58px; padding: 0 8px; font-size: 20px; border-bottom: 1px solid var(--line-light); }
  .primary-nav a:focus { outline-offset: -3px; }
  .primary-nav .nav-contact { padding: 0 8px; border: 0; border-bottom: 1px solid var(--line-light); }
  .menu-toggle[aria-expanded="true"] > span:nth-child(2) { top: 24px; transform: rotate(45deg); }
  .menu-toggle[aria-expanded="true"] > span:nth-child(3) { top: 24px; transform: rotate(-45deg); }
  body.menu-open { overflow: hidden; }
  .hero { min-height: 820px; }
  .hero-content { padding-inline: 0; }
  .hero h1 { font-size: clamp(50px, 10vw, 82px); }
  .opening { grid-template-columns: 1fr 2fr; }
  .opening-facts { grid-column: 2; }
  .route-heading { grid-template-columns: 1fr; }
  .route-heading > div:last-child { grid-template-columns: 1fr .75fr; }
  .route-step { grid-template-columns: 64px 1fr; min-height: 0; gap: 24px; padding: 44px 0 72px; }
  .route-step .step-number { grid-row: 1 / span 2; }
  .route-step .step-copy, .route-step-reverse .step-copy { grid-column: 2; grid-row: 1; order: initial; }
  .route-step figure, .route-step-reverse figure { grid-column: 2; grid-row: 2; order: initial; height: 330px; }
  .route-list::before { left: 31px; }
  .applications { grid-template-columns: 1fr; }
  .application-image { min-height: 520px; }
  .contact { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  html { scroll-padding-top: 76px; }
  .brand strong { font-size: 15px; }
  .brand small { display: none; }
  .brand-mark { width: 40px; height: 40px; }
  .hero { min-height: 760px; align-items: flex-end; }
  .hero-image { object-position: 62% center; }
  .hero-shade { background: linear-gradient(0deg, rgba(4,17,31,.98) 0%, rgba(4,17,31,.75) 64%, rgba(4,17,31,.35)); }
  .hero-content { width: calc(100% - 40px); margin: 76px auto 38px; padding: 78px 0; }
  .eyebrow { font-size: 10px; line-height: 1.5; }
  .hero h1 { font-size: clamp(46px, 14vw, 64px); }
  .hero-lead { font-size: 16px; }
  .hero-actions { display: grid; }
  .hero-index { display: none; }
  .opening, .materials { padding-inline: 20px; grid-template-columns: 1fr; }
  .opening-copy, .opening-facts { grid-column: 1; }
  .opening h2, .materials h2, .route h2, .applications h2 { font-size: clamp(38px, 11.5vw, 54px); }
  .route-heading { width: calc(100% - 40px); padding: 0; }
  .route-heading > div:last-child { grid-template-columns: 1fr; }
  .route-list { width: calc(100% - 24px); margin-left: 12px; }
  .route-list::before { left: 27px; }
  .route-step { grid-template-columns: 54px 1fr; gap: 14px; }
  .step-number span { width: 38px; height: 38px; }
  .step-copy h3 { font-size: 36px; }
  .route-step figure, .route-step-reverse figure { height: 230px; }
  .materials-intro { grid-template-columns: 1fr; gap: 28px; }
  .material-lines > div { padding: 20px 0; grid-template-columns: 40px 1fr; gap: 10px 14px; }
  .material-lines p { grid-column: 2; }
  .material-lines i { display: none; }
  .application-image { min-height: 330px; }
  .application-copy { padding: 70px 20px; }
  .contact { padding-inline: 20px; }
  .contact-details a, .contact-details p { grid-template-columns: 90px 1fr; font-size: 14px; }
  .field-row { grid-template-columns: 1fr; gap: 0; }
  .site-footer { padding: 42px 20px; align-items: flex-start; flex-direction: column; }
  .footer-meta { text-align: left; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
  .reveal { opacity: 1; transform: none; }
}