:root {
  --navy-950: #06131f;
  --navy-900: #071a2b;
  --navy-800: #0c2b43;
  --cyan-500: #2a9bcc;
  --cyan-300: #79c8e7;
  --steel-100: #dce6ec;
  --steel-50: #f2f6f8;
  --white: #ffffff;
  --ink: #102331;
  --muted: #5c6e79;
  --ember: #e45d3b;
  --line: rgba(10, 48, 72, 0.14);
  --shadow: 0 18px 60px rgba(0, 29, 48, 0.13);
  --max: 1240px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--steel-50);
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans CJK SC", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img { display: block; width: 100%; }
button { font: inherit; }

.utility-bar {
  min-height: 34px;
  color: rgba(255,255,255,.72);
  background: var(--navy-950);
  font: 11px/34px Arial, sans-serif;
  letter-spacing: .12em;
  text-transform: uppercase;
}
.utility-inner, .nav-inner, .wrap { width: min(calc(100% - 48px), var(--max)); margin-inline: auto; }
.utility-inner { display: flex; justify-content: space-between; gap: 24px; }
.utility-dot { color: var(--cyan-300); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(255,255,255,.94);
  border-bottom: 1px solid rgba(10, 48, 72, .09);
  backdrop-filter: blur(18px);
}
.nav-inner { min-height: 78px; display: flex; align-items: center; justify-content: space-between; gap: 36px; }
.brand { display: inline-flex; align-items: center; min-width: 196px; }
.brand-logo { width: auto; height: 56px; object-fit: contain; object-position: left center; }
.brand-mark {
  width: 42px; height: 42px; position: relative; display: grid; place-items: center;
  color: white; background: var(--navy-900); clip-path: polygon(50% 0, 100% 78%, 78% 100%, 22% 100%, 0 78%);
  font: 800 19px/1 Arial, sans-serif;
}
.brand-copy strong { display: block; font-size: 20px; letter-spacing: .18em; }
.brand-copy small { display: block; margin-top: 3px; color: var(--muted); font: 9px/1.2 Arial, sans-serif; letter-spacing: .1em; }
.site-nav { display: flex; align-items: center; gap: 30px; }
.nav-link { position: relative; padding: 27px 0 24px; color: #294353; font-size: 14px; }
.nav-link small { display: block; margin-top: 3px; color: #8a9aa4; font: 9px/1 Arial, sans-serif; letter-spacing: .12em; }
.nav-link::after { content: ""; position: absolute; left: 0; right: 100%; bottom: 17px; height: 2px; background: var(--cyan-500); transition: right .25s ease; }
.nav-link:hover::after, .nav-link.active::after { right: 0; }
.nav-status { padding: 10px 13px; border: 1px solid rgba(228,93,59,.42); color: #a33d25; font-size: 11px; letter-spacing: .08em; }
.menu-button { display: none; border: 0; background: transparent; color: var(--navy-900); font-size: 26px; }

.hero {
  min-height: 690px;
  position: relative;
  display: grid;
  align-items: center;
  color: white;
  overflow: hidden;
  background: var(--navy-900);
}
.hero::before { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, rgba(4,18,30,.96) 0%, rgba(5,28,45,.84) 38%, rgba(5,27,43,.15) 75%), linear-gradient(0deg, rgba(5,22,36,.72), transparent 45%); z-index: 1; }
.hero::after { content: ""; position: absolute; left: calc(50% - 620px); bottom: 0; width: 520px; height: 3px; background: linear-gradient(90deg, var(--ember) 0 26%, var(--cyan-500) 26% 100%); z-index: 3; }
.hero-image { position: absolute; inset: 0; height: 100%; object-fit: cover; object-position: 60% center; opacity: .92; }
.hero-grid { position: absolute; inset: 0; z-index: 2; pointer-events: none; background-image: linear-gradient(rgba(255,255,255,.035) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.035) 1px, transparent 1px); background-size: 82px 82px; mask-image: linear-gradient(90deg,#000,transparent 62%); }
.hero-content { position: relative; z-index: 3; width: min(calc(100% - 48px), var(--max)); margin-inline: auto; padding: 100px 0 110px; }
.eyebrow { display: flex; align-items: center; gap: 12px; margin: 0 0 24px; color: var(--cyan-300); font: 700 12px/1.3 Arial, sans-serif; letter-spacing: .22em; text-transform: uppercase; }
.eyebrow::before { content: ""; width: 34px; height: 1px; background: currentColor; }
.hero h1 { max-width: 920px; margin: 0; font-size: clamp(46px, 6.5vw, 92px); line-height: .98; letter-spacing: -.055em; }
.hero h1 strong { display: block; font: inherit; white-space: nowrap; }
.hero h1 span { display: block; margin-top: 18px; font-size: clamp(20px, 2.2vw, 31px); font-weight: 400; letter-spacing: .04em; color: #d6e7ee; }
.hero-lead { max-width: 600px; margin: 30px 0 34px; color: rgba(255,255,255,.78); font-size: 17px; line-height: 1.9; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 48px; padding: 0 22px; border: 1px solid transparent; font-size: 13px; font-weight: 700; letter-spacing: .08em; transition: .22s ease; }
.button.primary { color: white; background: var(--cyan-500); }
.button.primary:hover { background: #1886b5; transform: translateY(-2px); }
.button.ghost { color: white; border-color: rgba(255,255,255,.42); }
.button.ghost:hover { background: rgba(255,255,255,.1); }
.stage-flag { display: inline-flex; align-items: center; gap: 10px; margin-top: 40px; padding: 12px 14px; border-left: 2px solid var(--ember); background: rgba(7,26,43,.76); font-size: 12px; color: #dbe7ed; }
.stage-flag b { color: white; }

.capability-strip { position: relative; z-index: 6; margin-top: -48px; }
.capability-grid { display: grid; grid-template-columns: repeat(4, 1fr); background: white; box-shadow: var(--shadow); }
.capability-item { position: relative; min-height: 120px; padding: 26px 28px; border-right: 1px solid var(--line); }
.capability-item:last-child { border-right: 0; }
.capability-item span { color: var(--cyan-500); font: 700 11px/1 Arial, sans-serif; letter-spacing: .18em; }
.capability-item strong { display: block; margin-top: 13px; font-size: 18px; }
.capability-item small { display: block; margin-top: 6px; color: var(--muted); }

.section { padding: 108px 0; }
.section.white { background: white; }
.section.dark { color: white; background: var(--navy-900); }
.section-head { display: grid; grid-template-columns: 1fr 1fr; align-items: end; gap: 64px; margin-bottom: 44px; }
.kicker { margin: 0 0 14px; color: var(--cyan-500); font: 700 11px/1.2 Arial, sans-serif; letter-spacing: .2em; text-transform: uppercase; }
.section h2, .page-hero h1 { margin: 0; font-size: clamp(33px, 4vw, 56px); line-height: 1.12; letter-spacing: -.035em; }
.section-head p { margin: 0; color: var(--muted); font-size: 15px; line-height: 1.9; }
.dark .section-head p { color: rgba(255,255,255,.65); }

.product-grid { display: grid; grid-template-columns: repeat(12, 1fr); gap: 18px; }
.product-card { position: relative; min-height: 440px; overflow: hidden; background: var(--navy-900); color: white; }
.product-card:nth-child(1), .product-card:nth-child(4) { grid-column: span 7; }
.product-card:nth-child(2), .product-card:nth-child(3) { grid-column: span 5; }
.product-card img { position: absolute; inset: 0; height: 100%; object-fit: cover; transition: transform .65s ease; }
.product-card::after { content: ""; position: absolute; inset: 0; background: linear-gradient(0deg, rgba(3,18,29,.96) 0%, rgba(4,20,33,.28) 67%, transparent); }
.product-card:hover img { transform: scale(1.035); }
.product-copy { position: absolute; z-index: 2; left: 30px; right: 30px; bottom: 28px; }
.product-index { display: block; margin-bottom: 10px; color: var(--cyan-300); font: 700 11px/1 Arial, sans-serif; letter-spacing: .18em; }
.product-card h3 { margin: 0 0 9px; font-size: 24px; }
.product-card p { max-width: 560px; margin: 0; color: rgba(255,255,255,.72); font-size: 13px; line-height: 1.7; }

.aftermarket-section { position: relative; overflow: hidden; }
.aftermarket-section::after { content: "MRO"; position: absolute; right: -42px; bottom: -68px; color: rgba(255,255,255,.03); font: 900 250px/.8 Arial, sans-serif; letter-spacing: -.08em; pointer-events: none; }
.aftermarket-section .wrap { position: relative; z-index: 1; }
.aftermarket-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: rgba(255,255,255,.13); }
.aftermarket-card { min-height: 250px; padding: 30px 28px; background: rgba(7,26,43,.96); border-top: 3px solid transparent; transition: border-color .22s ease, background .22s ease; }
.aftermarket-card:hover { border-top-color: var(--cyan-500); background: var(--navy-800); }
.aftermarket-card span { color: var(--cyan-300); font: 800 11px/1 Arial, sans-serif; letter-spacing: .16em; }
.aftermarket-card h3 { margin: 40px 0 14px; font-size: 20px; line-height: 1.45; }
.aftermarket-card p { margin: 0; color: rgba(255,255,255,.64); font-size: 14px; line-height: 1.8; }
.section-link { display: inline-flex; align-items: center; gap: 12px; margin-top: 28px; color: var(--cyan-300); font-size: 14px; font-weight: 700; }
.section-link span { transition: transform .2s ease; }
.section-link:hover span { transform: translateX(4px); }

.split-feature { display: grid; grid-template-columns: 1.08fr .92fr; min-height: 540px; background: white; box-shadow: 0 12px 50px rgba(0, 28, 46, .08); }
.split-feature.reverse { grid-template-columns: .92fr 1.08fr; }
.split-media { min-height: 430px; }
.split-media img { height: 100%; object-fit: cover; }
.split-copy { padding: 72px 64px; display: flex; flex-direction: column; justify-content: center; }
.split-copy h3 { margin: 0 0 22px; font-size: clamp(28px, 3vw, 42px); line-height: 1.25; }
.split-copy p { margin: 0 0 24px; color: var(--muted); line-height: 1.9; }
.calibration-list { display: grid; gap: 13px; padding: 0; margin: 10px 0 0; list-style: none; }
.calibration-list li { display: grid; grid-template-columns: 38px 1fr; gap: 14px; align-items: center; font-size: 14px; }
.calibration-list li::before { content: attr(data-no); color: var(--cyan-500); font: 700 10px/28px Arial, sans-serif; text-align: center; border-top: 1px solid var(--cyan-500); border-bottom: 1px solid var(--cyan-500); }

.research-band { position: relative; overflow: hidden; }
.research-band::before { content: "R&D"; position: absolute; right: -28px; bottom: -68px; color: rgba(255,255,255,.035); font: 900 260px/.8 Arial, sans-serif; letter-spacing: -.08em; }
.research-grid { position: relative; z-index: 2; display: grid; grid-template-columns: .9fr 1.1fr; gap: 70px; align-items: center; }
.research-frame { position: relative; }
.research-frame img { aspect-ratio: 16/11; object-fit: cover; }
.research-frame::after { content: "SHENYANG · COLLABORATIVE RESEARCH"; position: absolute; left: -20px; bottom: 22px; padding: 12px 18px; color: white; background: var(--ember); font: 700 10px/1 Arial, sans-serif; letter-spacing: .14em; }
.research-copy h2 { margin: 0 0 25px; }
.research-copy > p { color: rgba(255,255,255,.68); line-height: 1.9; }
.lab-notes { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; margin-top: 32px; background: rgba(255,255,255,.12); }
.lab-note { padding: 18px; background: var(--navy-900); }
.lab-note b { display: block; color: var(--cyan-300); font-size: 14px; }
.lab-note small { display: block; margin-top: 7px; color: rgba(255,255,255,.5); }

.page-hero { position: relative; min-height: 390px; display: flex; align-items: end; color: white; background: var(--navy-900); overflow: hidden; }
.page-hero img { position: absolute; inset: 0; height: 100%; object-fit: cover; opacity: .48; }
.page-hero::after { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, rgba(4,20,32,.95), rgba(4,20,32,.34)), linear-gradient(0deg, rgba(4,20,32,.8), transparent); }
.page-hero-content { position: relative; z-index: 2; padding: 95px 0 60px; }
.page-hero p { max-width: 630px; margin: 20px 0 0; color: rgba(255,255,255,.73); line-height: 1.8; }
.breadcrumb { margin-bottom: 24px; color: var(--cyan-300); font: 700 10px/1 Arial, sans-serif; letter-spacing: .16em; text-transform: uppercase; }

.detail-stack { display: grid; gap: 22px; }
.detail-card { display: grid; grid-template-columns: 1fr 1.12fr; min-height: 380px; overflow: hidden; background: white; border: 1px solid var(--line); }
.detail-card:nth-child(even) { grid-template-columns: 1.12fr 1fr; }
.detail-card:nth-child(even) .detail-image { order: 2; }
.detail-image img { height: 100%; object-fit: cover; }
.detail-copy { padding: 52px; }
.detail-copy .number { color: var(--cyan-500); font: 800 11px/1 Arial, sans-serif; letter-spacing: .18em; }
.detail-copy h2 { margin: 15px 0 15px; font-size: 31px; }
.detail-copy p { color: var(--muted); line-height: 1.8; }
.tag-row { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 24px; }
.tag { padding: 8px 10px; color: #315163; background: var(--steel-50); border: 1px solid var(--line); font-size: 11px; }

.material-system { display: grid; grid-template-columns: repeat(4,1fr); gap: 14px; margin-top: 40px; }
.material-cell { min-height: 170px; padding: 24px; color: white; background: var(--navy-800); border-top: 3px solid var(--cyan-500); }
.material-cell b { display: block; margin-bottom: 12px; font-size: 16px; }
.material-cell p { margin: 0; color: rgba(255,255,255,.62); font-size: 13px; line-height: 1.7; }

.application-hero { min-height: 470px; }
.application-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.application-card { min-height: 390px; padding: 40px; background: var(--steel-50); border: 1px solid var(--line); border-top: 3px solid var(--cyan-500); }
.application-card:nth-child(2), .application-card:nth-child(5) { background: white; }
.application-card > span { color: var(--cyan-500); font: 800 11px/1 Arial, sans-serif; letter-spacing: .16em; }
.application-card h3 { margin: 34px 0 16px; font-size: 24px; line-height: 1.35; }
.application-card p { margin: 0; color: var(--muted); font-size: 15px; line-height: 1.85; }
.application-card ul { display: grid; gap: 10px; margin: 28px 0 0; padding: 0; list-style: none; }
.application-card li { position: relative; padding: 11px 0 0 18px; border-top: 1px solid var(--line); color: #315163; font-size: 14px; line-height: 1.55; }
.application-card li::before { content: ""; position: absolute; left: 0; top: 17px; width: 6px; height: 6px; background: var(--cyan-500); }
.application-process { display: grid; gap: 44px; }
.application-process .research-copy { max-width: 820px; }
.process-band { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; margin-bottom: 24px; background: var(--line); border: 1px solid var(--line); }
.process-band > div { min-height: 150px; padding: 24px; background: white; }
.process-band span { color: var(--cyan-500); font: 800 10px/1 Arial, sans-serif; letter-spacing: .13em; }
.process-band b { display: block; margin-top: 28px; font-size: 16px; }
.process-band small { display: block; margin-top: 8px; color: var(--muted); font-size: 13px; line-height: 1.6; }
.process-band-dark { margin-bottom: 0; background: rgba(255,255,255,.13); border-color: rgba(255,255,255,.13); }
.process-band-dark > div { color: white; background: var(--navy-800); }
.process-band-dark small { color: rgba(255,255,255,.58); }
.scope-note { margin: 18px 0 0; color: var(--muted); font-size: 13px; line-height: 1.75; }

.status-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.status-card { min-height: 420px; padding: 44px; color: white; background: var(--navy-900); position: relative; overflow: hidden; }
.status-card::after { content: attr(data-code); position: absolute; right: -8px; bottom: -25px; color: rgba(255,255,255,.045); font: 900 94px/1 Arial, sans-serif; }
.status-chip { display: inline-flex; padding: 9px 11px; color: white; background: var(--ember); font-size: 11px; letter-spacing: .08em; }
.status-chip.blue { background: var(--cyan-500); }
.status-card h2 { margin: 26px 0 12px; font-size: 34px; }
.status-card h3 { margin: -4px 0 18px; color: #edf6fa; font-size: 17px; font-weight: 700; }
.status-card p { color: rgba(255,255,255,.64); line-height: 1.85; }
.status-card ul { display: grid; gap: 12px; margin: 28px 0 0; padding: 0; list-style: none; }
.status-card li { padding-top: 12px; border-top: 1px solid rgba(255,255,255,.12); color: #dfe9ee; font-size: 13px; }
.quality-summary { margin-top: 34px; border-top: 1px solid var(--line); padding-top: 34px; }
.quality-summary-head { display: flex; align-items: end; justify-content: space-between; gap: 32px; margin-bottom: 20px; }
.quality-summary-head h3 { margin: 0; font-size: 26px; }
.quality-summary-head > p { max-width: 420px; margin: 0; color: var(--muted); font-size: 14px; line-height: 1.7; text-align: right; }
.timeline { display: grid; grid-template-columns: repeat(5,1fr); gap: 0; margin-top: 48px; }
.timeline-step { position: relative; padding: 38px 16px 0 0; border-top: 1px solid #afc1cb; }
.timeline-step::before { content: ""; position: absolute; top: -6px; left: 0; width: 11px; height: 11px; border-radius: 50%; background: white; border: 2px solid var(--cyan-500); }
.timeline-step.current::before { background: var(--ember); border-color: var(--ember); box-shadow: 0 0 0 7px rgba(228,93,59,.12); }
.timeline-step b { display: block; font-size: 14px; }
.timeline-step small { display: block; margin-top: 7px; color: var(--muted); line-height: 1.55; }
.qualification-home { padding-bottom: 28px; }
.qualification-pair { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.qualification-pair a { position: relative; display: grid; min-height: 230px; padding: 36px 40px; color: white; background: var(--navy-900); border-top: 3px solid var(--cyan-500); transition: transform .22s ease, background .22s ease; }
.qualification-pair a:hover { transform: translateY(-3px); background: var(--navy-800); }
.qualification-pair span { color: var(--cyan-300); font: 700 10px/1 Arial, sans-serif; letter-spacing: .14em; }
.qualification-pair strong { align-self: end; margin-top: 30px; font: 800 38px/1 Arial, sans-serif; }
.qualification-pair b { margin-top: 9px; font-size: 17px; }
.qualification-pair small { margin-top: 20px; color: rgba(255,255,255,.62); font-size: 13px; }

.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 58px; align-items: center; }
.about-copy p { color: var(--muted); line-height: 1.95; }
.about-visual { position: relative; }
.about-visual img { aspect-ratio: 4/3; object-fit: cover; }
.about-visual::before { content: "TIANJIN AIRPORT ECONOMIC AREA"; position: absolute; z-index: 2; left: -22px; top: 28px; padding: 12px 16px; color: white; background: var(--navy-900); font: 700 10px/1 Arial, sans-serif; letter-spacing: .12em; }
.principle-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); }
.principle { min-height: 230px; padding: 30px; background: white; }
.principle span { color: var(--cyan-500); font: 800 11px/1 Arial, sans-serif; }
.principle h3 { margin: 45px 0 12px; font-size: 20px; }
.principle p { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.7; }

.collaboration-section { color: white; background: var(--navy-950); }
.collaboration-panel { position: relative; overflow: hidden; padding: 72px; background: linear-gradient(135deg, var(--navy-800), var(--navy-900)); border-top: 3px solid var(--cyan-500); }
.collaboration-panel::after { content: "OPEN"; position: absolute; right: -26px; top: -18px; color: rgba(255,255,255,.035); font: 900 150px/.9 Arial, sans-serif; letter-spacing: -.06em; pointer-events: none; }
.collaboration-intro { position: relative; z-index: 1; display: grid; grid-template-columns: .85fr 1.15fr; gap: 72px; align-items: end; }
.collaboration-intro h2 { max-width: 520px; }
.collaboration-intro > p:last-child { margin: 0; color: rgba(255,255,255,.69); line-height: 1.9; }
.collaboration-paths { position: relative; z-index: 1; display: grid; grid-template-columns: repeat(3,1fr); gap: 1px; margin-top: 52px; background: rgba(255,255,255,.13); }
.collaboration-paths article { min-height: 286px; padding: 30px; background: rgba(7,26,43,.94); }
.collaboration-paths span { color: var(--cyan-300); font: 800 11px/1 Arial, sans-serif; letter-spacing: .16em; }
.collaboration-paths h3 { margin: 34px 0 14px; font-size: 21px; }
.collaboration-paths p { margin: 0; color: rgba(255,255,255,.65); font-size: 13px; line-height: 1.85; }
.ecosystem-note { position: relative; z-index: 1; margin: 24px 0 0; color: rgba(255,255,255,.48); font-size: 12px; line-height: 1.7; }
.cooperation-bridge { display: grid; grid-template-columns: 1fr 1.1fr auto; gap: 46px; align-items: center; margin-bottom: 28px; padding: 34px 38px; color: white; background: var(--navy-900); border-left: 3px solid var(--cyan-500); transition: transform .22s ease, background .22s ease; }
.cooperation-bridge:hover { transform: translateY(-2px); background: var(--navy-800); }
.cooperation-bridge small { display: block; margin-bottom: 9px; color: var(--cyan-300); font: 700 10px/1 Arial, sans-serif; letter-spacing: .17em; }
.cooperation-bridge strong { display: block; font-size: 20px; }
.cooperation-bridge p { margin: 0; color: rgba(255,255,255,.66); font-size: 13px; line-height: 1.75; }
.cooperation-bridge b { white-space: nowrap; color: var(--cyan-300); font-size: 12px; }

.notice { padding: 18px 20px; color: #6e4439; background: #fff0eb; border-left: 3px solid var(--ember); font-size: 13px; line-height: 1.7; }
.footer { color: rgba(255,255,255,.7); background: var(--navy-950); }
.footer-main { display: grid; grid-template-columns: 1.2fr .8fr .8fr; gap: 56px; padding: 70px 0 52px; }
.footer h3 { margin: 0 0 17px; color: white; font-size: 16px; }
.footer p, .footer li { font-size: 12px; line-height: 1.9; }
.footer ul { list-style: none; padding: 0; margin: 0; }
.footer-bottom { display: flex; justify-content: space-between; gap: 20px; padding: 19px 0; border-top: 1px solid rgba(255,255,255,.1); font-size: 11px; }

[data-reveal] { opacity: 0; transform: translateY(18px); transition: opacity .7s ease, transform .7s ease; }
[data-reveal].is-visible { opacity: 1; transform: none; }

@media (max-width: 980px) {
  .menu-button { display: block; }
  .site-nav { display: none; position: absolute; left: 0; right: 0; top: 78px; flex-direction: column; align-items: stretch; gap: 0; padding: 10px 24px 22px; background: white; border-bottom: 1px solid var(--line); }
  .site-nav.is-open { display: flex; }
  .nav-link { padding: 14px 0; }
  .nav-status { margin-top: 10px; }
  .hero { min-height: 630px; }
  .capability-grid { grid-template-columns: 1fr 1fr; }
  .capability-item:nth-child(2) { border-right: 0; }
  .capability-item:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .section-head, .research-grid, .about-grid, .collaboration-intro { grid-template-columns: 1fr; }
  .aftermarket-grid, .application-grid { grid-template-columns: 1fr 1fr; }
  .collaboration-paths { grid-template-columns: 1fr; }
  .collaboration-paths article { min-height: 0; }
  .cooperation-bridge { grid-template-columns: 1fr; gap: 18px; }
  .product-card:nth-child(n) { grid-column: span 6; }
  .split-feature, .split-feature.reverse, .detail-card, .detail-card:nth-child(even) { grid-template-columns: 1fr; }
  .detail-card:nth-child(even) .detail-image { order: 0; }
  .split-media, .detail-image { min-height: 360px; }
  .material-system, .principle-grid, .process-band { grid-template-columns: 1fr 1fr; }
  .footer-main { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 660px) {
  .utility-inner, .nav-inner, .wrap, .hero-content { width: min(calc(100% - 30px), var(--max)); }
  .utility-inner span:last-child { display: none; }
  .brand-copy small { display: none; }
  .brand-logo { height: 48px; }
  .hero { min-height: 690px; }
  .hero::before { background: linear-gradient(90deg, rgba(4,18,30,.94), rgba(5,28,45,.55)), linear-gradient(0deg, rgba(5,22,36,.9), transparent); }
  .hero-content { padding-top: 80px; }
  .hero h1 { font-size: 49px; }
  .hero h1 strong { white-space: normal; }
  .capability-strip { margin-top: -30px; }
  .capability-grid, .section-head, .product-grid, .status-grid, .material-system, .principle-grid, .qualification-pair, .footer-main, .aftermarket-grid, .application-grid, .process-band { grid-template-columns: 1fr; }
  .capability-item { border-right: 0; border-bottom: 1px solid var(--line); }
  .section { padding: 76px 0; }
  .product-card:nth-child(n) { grid-column: 1; min-height: 390px; }
  .split-copy, .detail-copy { padding: 42px 28px; }
  .collaboration-panel { padding: 48px 26px; }
  .collaboration-panel::after { font-size: 92px; }
  .cooperation-bridge { padding: 28px 24px; }
  .lab-notes { grid-template-columns: 1fr; }
  .status-card { padding: 34px 26px; }
  .application-card { min-height: 0; padding: 34px 26px; }
  .quality-summary-head { display: block; }
  .quality-summary-head > p { margin-top: 12px; text-align: left; }
  .timeline { grid-template-columns: 1fr; margin-left: 8px; }
  .timeline-step { padding: 10px 0 28px 28px; border-top: 0; border-left: 1px solid #afc1cb; }
  .timeline-step::before { top: 10px; left: -6px; }
  .footer-bottom { flex-direction: column; }
}