:root {
  --blue: #078dcc;
  --blue-deep: #073b5a;
  --blue-soft: #e9f6fb;
  --red: #ed1c24;
  --ink: #14232d;
  --muted: #647681;
  --line: #dce5e9;
  --paper: #f4f7f8;
  --white: #fff;
  --amber: #efb53c;
  --shadow: 0 18px 46px rgba(7, 59, 90, .12);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--white); font-family: Arial, "Microsoft YaHei", sans-serif; line-height: 1.55; }
body.menu-open { overflow: hidden; }
img { max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
.container { width: min(1180px, calc(100% - 48px)); margin: 0 auto; }

.site-header { position: fixed; z-index: 50; inset: 0 0 auto; height: 76px; background: rgba(255,255,255,.97); border-bottom: 1px solid rgba(220,229,233,.92); }
.header-inner { height: 100%; display: flex; align-items: center; justify-content: space-between; gap: 26px; }
.brand { display: flex; align-items: center; gap: 13px; min-width: 210px; }
.brand img { width: 122px; height: 52px; display: block; object-fit: contain; }
.brand-copy { display: grid; padding-left: 13px; border-left: 1px solid var(--line); line-height: 1.12; }
.brand-copy strong { color: var(--blue-deep); font-size: 13px; }
.brand-copy small { margin-top: 4px; color: var(--muted); font-size: 9px; }
.desktop-nav { display: flex; align-items: center; gap: 19px; font-size: 14px; font-weight: 600; }
.desktop-nav a { position: relative; height: 76px; display: flex; align-items: center; white-space: nowrap; }
.desktop-nav a::after { content: ""; position: absolute; left: 0; right: 0; bottom: 18px; height: 2px; background: var(--red); transform: scaleX(0); transition: transform .2s ease; }
.desktop-nav a:hover::after, .desktop-nav a.active::after { transform: scaleX(1); }
.desktop-nav a.active { color: var(--blue-deep); }
.header-cta { min-height: 38px; display: inline-flex; align-items: center; gap: 7px; padding: 0 13px; border-radius: 4px; background: var(--blue-deep); color: var(--white); font-size: 13px; font-weight: 700; white-space: nowrap; }
.header-cta svg { width: 16px; height: 16px; }
.menu-button { display: none; width: 40px; height: 40px; place-items: center; border: 1px solid var(--line); border-radius: 4px; color: var(--blue-deep); background: var(--white); }
.menu-button svg { width: 20px; height: 20px; }
.mobile-nav { position: fixed; z-index: 49; inset: 76px 0 0; padding: 16px 24px 28px; background: var(--white); transform: translateX(100%); transition: transform .25s ease; overflow-y: auto; }
.mobile-nav.open { transform: translateX(0); }
.mobile-nav a { display: flex; align-items: center; justify-content: space-between; min-height: 54px; border-bottom: 1px solid var(--line); color: var(--blue-deep); font-weight: 700; }
.mobile-nav a::after { content: "→"; color: var(--red); }

.home-hero { min-height: 720px; padding-top: 76px; position: relative; isolation: isolate; display: grid; align-items: center; background: #f4f8fa url("optical/optical-16t.png") center / cover no-repeat; }
.home-hero::before { content: ""; position: absolute; inset: 0; z-index: -1; background: rgba(255,255,255,.72); }
.home-hero-inner { display: grid; grid-template-columns: minmax(0, 650px) 1fr; min-height: 644px; align-items: center; padding: 88px 0 54px; }
.overline { display: inline-flex; align-items: center; gap: 10px; color: var(--blue); font-size: 13px; font-weight: 800; text-transform: uppercase; }
.overline::before { content: ""; width: 28px; height: 2px; background: var(--red); }
h1, h2, h3, p { overflow-wrap: anywhere; }
h1 { max-width: 720px; margin: 17px 0 22px; color: var(--blue-deep); font-size: clamp(45px, 6vw, 76px); line-height: 1.04; font-weight: 780; }
.hero-copy { max-width: 590px; margin: 0 0 30px; color: #324c5d; font-size: 19px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.button { min-height: 48px; display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 0 21px; border: 1px solid transparent; border-radius: 4px; font-weight: 750; transition: transform .2s ease, background .2s ease; }
.button:hover { transform: translateY(-2px); }
.button svg { width: 18px; height: 18px; }
.button.primary { background: var(--blue-deep); color: var(--white); }
.button.signal { background: var(--red); color: var(--white); }
.button.outline { color: var(--blue-deep); border-color: var(--blue-deep); background: rgba(255,255,255,.62); }
.hero-index { align-self: end; justify-self: end; width: min(360px,100%); display: grid; gap: 1px; background: rgba(7,59,90,.18); }
.hero-index a { min-height: 72px; display: grid; grid-template-columns: 36px 1fr auto; align-items: center; gap: 10px; padding: 0 18px; background: rgba(255,255,255,.88); color: var(--blue-deep); font-weight: 700; }
.hero-index a:first-child { border-left: 3px solid var(--red); }
.hero-index span { color: var(--red); font-size: 12px; }
.hero-index svg { width: 17px; height: 17px; }

.page-hero { min-height: 520px; padding-top: 76px; position: relative; isolation: isolate; display: grid; align-items: end; color: var(--white); background: var(--blue-deep); }
.page-hero::before { content: ""; position: absolute; inset: 0; z-index: -2; background-position: center; background-size: cover; }
.page-hero::after { content: ""; position: absolute; inset: 0; z-index: -1; background: rgba(5,38,57,.74); }
.page-hero.optical::before { background-image: url("optical/optical-16t.png"); background-position: center; }
.page-hero.ai::before { background-image: url("ai-server-room.png"); }
.page-hero.energy::before { background-image: url("hero-industrial.jpg"); }
.page-hero.solutions::before { background-image: url("solution-system.jpg"); }
.page-hero.about::before { background-image: url("about-hero-wave.jpeg"); background-position: center; }
.page-hero.contact::before { background-image: url("contact-ai-robot.png"); }
.page-hero-inner { padding: 78px 0 66px; }
.breadcrumb { display: flex; flex-wrap: wrap; gap: 8px; color: #d5e8f2; font-size: 13px; }
.page-hero h1 { color: var(--white); font-size: clamp(42px, 5vw, 64px); margin-bottom: 15px; }
.page-hero p { max-width: 680px; margin: 0; color: #e5f0f5; font-size: 18px; }

section { padding: 88px 0; }
.section-head { display: grid; grid-template-columns: 1fr minmax(260px,430px); align-items: end; gap: 38px; margin-bottom: 36px; }
.section-tag { color: var(--blue); font-size: 12px; font-weight: 800; text-transform: uppercase; }
h2 { margin: 7px 0 0; color: var(--ink); font-size: 38px; line-height: 1.17; }
.section-head p { margin: 0; color: var(--muted); font-size: 15px; }
.paper { background: var(--paper); }
.deep { background: var(--blue-deep); color: var(--white); }
.deep h2 { color: var(--white); }
.deep .section-tag { color: #7dd6f2; }
.deep .section-head p { color: #c9dce6; }

.business-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); }
.business-card { min-height: 330px; padding: 30px; background: var(--white); display: flex; flex-direction: column; transition: background .2s ease, transform .2s ease; }
.business-card:hover { position: relative; z-index: 1; background: var(--blue-soft); transform: translateY(-4px); box-shadow: var(--shadow); }
.business-card .business-number { color: var(--red); font-size: 12px; font-weight: 800; }
.business-card .business-icon { width: 54px; height: 54px; display: grid; place-items: center; margin: 44px 0 22px; border-radius: 4px; background: var(--blue-soft); color: var(--blue-deep); }
.business-card .business-icon svg { width: 27px; height: 27px; }
.business-card h3 { margin: 0 0 10px; color: var(--blue-deep); font-size: 23px; }
.business-card p { margin: 0; color: var(--muted); font-size: 14px; }
.business-card .card-link { margin-top: auto; padding-top: 22px; display: inline-flex; align-items: center; gap: 7px; color: var(--blue); font-size: 13px; font-weight: 800; }
.business-card .card-link svg { width: 16px; height: 16px; }

.feature-split { display: grid; grid-template-columns: 1.04fr .96fr; gap: 48px; align-items: center; }
.feature-media { min-height: 470px; position: relative; overflow: hidden; border-radius: 4px; background: #e9eef0; }
.feature-media img { width: 100%; height: 100%; display: block; object-fit: cover; position: absolute; inset: 0; }
.feature-copy h2 { margin-bottom: 20px; }
.feature-copy > p { color: var(--muted); font-size: 16px; }
.feature-list { display: grid; margin: 28px 0; border-top: 1px solid var(--line); }
.feature-list div { min-height: 62px; display: grid; grid-template-columns: 29px 1fr; gap: 12px; align-items: center; border-bottom: 1px solid var(--line); }
.feature-list svg { width: 19px; height: 19px; color: var(--blue); }

.product-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 16px; }
.product-card { min-height: 390px; display: flex; flex-direction: column; overflow: hidden; border: 1px solid var(--line); border-radius: 4px; background: var(--white); }
.product-card-media { height: 235px; overflow: hidden; background: #f7f9fa; }
.product-card-media img { width: 100%; height: 100%; display: block; object-fit: cover; object-position: top center; }
.product-card-media.product-shot img { padding: 18px; object-fit: contain; object-position: center; }
.product-card-media.product-shot.pdu { background: #020202; }
.product-card-media.product-shot.pdu img { padding: 0; }
.product-card-body { padding: 21px; }
.product-card small { color: var(--blue); font-weight: 800; }
.product-card h3 { margin: 8px 0 8px; color: var(--blue-deep); font-size: 20px; line-height: 1.3; }
.product-card p { margin: 0; color: var(--muted); font-size: 14px; }

.category-strip { display: grid; grid-template-columns: repeat(4,1fr); gap: 1px; margin-bottom: 42px; background: var(--line); border: 1px solid var(--line); }
.category-strip a { min-height: 106px; padding: 22px; background: var(--white); }
.category-strip strong { display: block; color: var(--blue-deep); font-size: 19px; }
.category-strip span { color: var(--muted); font-size: 12px; }

.steps { display: grid; grid-template-columns: repeat(4,1fr); gap: 1px; background: rgba(255,255,255,.22); }
.step { min-height: 250px; padding: 28px; background: #0b496c; }
.step .step-no { color: var(--amber); font-size: 13px; font-weight: 800; }
.step h3 { margin: 68px 0 10px; color: var(--white); font-size: 20px; }
.step p { margin: 0; color: #cbdfe9; font-size: 14px; }

.spec-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.spec-table th, .spec-table td { padding: 15px 16px; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
.spec-table th { color: var(--blue-deep); background: var(--blue-soft); font-size: 13px; }
.spec-table td { color: #3d505c; }

.application-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 16px; }
.application { min-height: 245px; padding: 26px; border: 1px solid var(--line); border-radius: 4px; background: var(--white); }
.application svg { width: 30px; height: 30px; color: var(--red); }
.application h3 { margin: 36px 0 9px; color: var(--blue-deep); font-size: 20px; }
.application p { color: var(--muted); margin: 0; font-size: 14px; }

.about-grid { display: block; }
.about-photo { display: none; }
.about-photo img { width: 100%; height: 100%; display: block; object-fit: cover; }
.about-text { max-width: 1080px; }
.about-text p { color: #425663; font-size: 16px; }
.facts { display: grid; grid-template-columns: 1fr 1fr; margin-top: 26px; border-top: 1px solid var(--line); border-left: 1px solid var(--line); }
.fact { min-height: 120px; padding: 20px; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.fact strong { display: block; color: var(--blue-deep); font-size: 24px; }
.fact span { color: var(--muted); font-size: 12px; }

.certificate-band { display: grid; grid-template-columns: .9fr 1.1fr; gap: 46px; align-items: center; }
.certificate-mark { min-height: 260px; display: grid; place-items: center; border: 1px solid rgba(255,255,255,.28); border-radius: 4px; text-align: center; }
.certificate-mark svg { width: 62px; height: 62px; color: var(--amber); }
.certificate-mark strong { display: block; font-size: 24px; }
.certificate-list { display: grid; gap: 0; }
.certificate-list div { padding: 16px 0; border-bottom: 1px solid rgba(255,255,255,.22); }
.certificate-list strong { display: block; color: var(--white); }
.certificate-list span { color: #c9dce6; font-size: 13px; }

.contact-grid { display: grid; grid-template-columns: .86fr 1.14fr; gap: 60px; }
.contact-grid.solo { grid-template-columns: minmax(0, 720px); }
.contact-panel { padding: 28px; border: 1px solid var(--line); border-radius: 4px; background: var(--paper); }
.contact-panel h2 { font-size: 28px; }
.contact-line { display: grid; grid-template-columns: 28px 1fr; gap: 12px; padding: 15px 0; border-top: 1px solid var(--line); }
.contact-line svg { width: 19px; height: 19px; color: var(--blue); margin-top: 3px; }
.contact-line p { margin: 0; color: #41535f; font-size: 14px; }
.contact-form { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.field { display: grid; gap: 7px; }
.field.full { grid-column: 1 / -1; }
.field label { color: var(--muted); font-size: 12px; font-weight: 800; }
.field input, .field select, .field textarea { width: 100%; min-height: 46px; padding: 11px 12px; border: 1px solid var(--line); border-radius: 3px; color: var(--ink); background: var(--white); outline: none; }
.field textarea { min-height: 120px; resize: vertical; }
.field input:focus, .field select:focus, .field textarea:focus { border-color: var(--blue); box-shadow: 0 0 0 3px rgba(7,141,204,.12); }
.form-status { min-height: 20px; grid-column: 1 / -1; margin: 0; color: var(--blue); font-size: 13px; }

.site-footer { padding: 46px 0 24px; color: #b8c8d1; background: #101d25; }
.footer-grid { display: grid; grid-template-columns: 1.35fr .75fr .75fr; gap: 36px; }
.footer-logo { width: 126px; height: auto; padding: 6px; background: var(--white); border-radius: 3px; }
.footer-grid h3 { margin: 0 0 12px; color: var(--white); font-size: 14px; }
.footer-grid p, .footer-grid a { margin: 7px 0; display: block; font-size: 13px; }
.footer-grid a:hover { color: var(--white); }
.footer-bottom { margin-top: 32px; padding-top: 18px; border-top: 1px solid rgba(255,255,255,.14); font-size: 12px; }
.to-top { position: fixed; z-index: 20; right: 20px; bottom: 20px; width: 44px; height: 44px; display: grid; place-items: center; border: 0; border-radius: 4px; color: var(--white); background: var(--blue); opacity: 0; pointer-events: none; transition: opacity .2s ease; box-shadow: var(--shadow); }
.to-top.visible { opacity: 1; pointer-events: auto; }
.to-top svg { width: 19px; height: 19px; }
.reveal { opacity: 0; transform: translateY(16px); transition: opacity .45s ease, transform .45s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }

@media (max-width: 1040px) {
  .desktop-nav { gap: 14px; font-size: 13px; }
  .brand-copy { display: none; }
  .brand { min-width: 126px; }
  .header-cta { display: none; }
}

@media (max-width: 840px) {
  .desktop-nav { display: none; }
  .menu-button { display: grid; }
  .home-hero-inner { grid-template-columns: 1fr; align-content: center; gap: 36px; }
  .hero-index { justify-self: start; }
  .section-head, .feature-split, .about-grid, .certificate-band, .contact-grid { grid-template-columns: 1fr; }
  .business-grid, .product-grid, .application-grid { grid-template-columns: 1fr 1fr; }
  .business-card:last-child, .product-card:last-child, .application:last-child { grid-column: 1 / -1; }
  .steps { grid-template-columns: 1fr 1fr; }
  .category-strip { grid-template-columns: 1fr 1fr; }
  .feature-media { min-height: 390px; }
}

@media (max-width: 600px) {
  .container { width: min(100% - 32px,1180px); }
  .site-header { height: 68px; }
  .brand img { width: 103px; height: 46px; }
  .mobile-nav { inset: 68px 0 0; }
  .home-hero { min-height: 690px; padding-top: 68px; background-position: 57% center; }
  .home-hero-inner { min-height: 622px; padding: 66px 0 30px; }
  h1 { font-size: 44px; }
  .hero-copy { font-size: 16px; }
  .hero-index { width: 100%; }
  .hero-index a { min-height: 58px; }
  .page-hero { min-height: 460px; padding-top: 68px; }
  .page-hero-inner { padding: 64px 0 44px; }
  .page-hero h1 { font-size: 42px; }
  section { padding: 62px 0; }
  h2 { font-size: 31px; }
  .section-head { gap: 13px; margin-bottom: 28px; }
  .business-grid, .product-grid, .application-grid, .steps, .category-strip { grid-template-columns: 1fr; }
  .business-card:last-child, .product-card:last-child, .application:last-child { grid-column: auto; }
  .business-card { min-height: 260px; }
  .business-card .business-icon { margin: 28px 0 20px; }
  .feature-media { min-height: 300px; }
  .facts { grid-template-columns: 1fr; }
  .contact-form { grid-template-columns: 1fr; }
  .field.full { grid-column: auto; }
  .footer-grid { grid-template-columns: 1fr; }
}