:root {
  --color-primary: #0b4f7c;
  --color-primary-dark: #06385b;
  --color-accent: #e67e22;
  --color-text: #222;
  --color-text-light: #555;
  --color-bg: #fff;
  --color-bg-alt: #f6f8fa;
  --color-overlay: rgba(8, 38, 62, 0.72);
  --radius: 6px;
  --shadow: 0 4px 18px rgba(0,0,0,0.08);
  --container: 1200px;
  --header-height: 64px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
}
img, picture { max-width: 100%; height: auto; display: block; }
a { color: var(--color-primary); text-underline-offset: 3px; }
a:hover, a:focus { color: var(--color-accent); }

.skip-link {
  position: absolute; left: -9999px; top: 0;
  background: var(--color-primary); color: #fff; padding: .5rem 1rem; z-index: 1000;
}
.skip-link:focus { left: 0; }

.container { width: 92%; max-width: var(--container); margin: 0 auto; }

/* Header */
.site-header {
  background: #fff;
  border-bottom: 1px solid #e5e8eb;
  position: sticky; top: 0; z-index: 500;
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: var(--header-height);
}
.logo {
  font-size: 1.35rem; font-weight: 800; color: var(--color-primary);
  text-decoration: none; letter-spacing: -0.02em;
}
.logo:hover, .logo:focus { color: var(--color-primary-dark); }

.nav-toggle {
  display: none; flex-direction: column; gap: 5px; padding: .5rem;
  background: none; border: none; cursor: pointer;
}
.nav-toggle span { display: block; width: 26px; height: 3px; background: var(--color-text); border-radius: 2px; }

.nav-list { display: flex; list-style: none; margin: 0; padding: 0; gap: .25rem; }
.nav-list a, .submenu-toggle {
  display: block; padding: .55rem .85rem; color: var(--color-text); text-decoration: none;
  font-size: .95rem; background: none; border: none; cursor: pointer; font-family: inherit;
}
.nav-list a:hover, .nav-list a:focus,
.submenu-toggle:hover, .submenu-toggle:focus { color: var(--color-primary); outline: none; }

.has-submenu { position: relative; }
.submenu {
  position: absolute; top: calc(100% + 2px); left: 0;
  min-width: 180px; background: #fff; border: 1px solid #e5e8eb; border-radius: var(--radius);
  box-shadow: var(--shadow); list-style: none; margin: 0; padding: .5rem 0;
  opacity: 0; visibility: hidden; transform: translateY(-6px); transition: opacity .2s, transform .2s;
}
.has-submenu:hover .submenu,
.has-submenu:focus-within .submenu,
.submenu-toggle[aria-expanded="true"] + .submenu { opacity: 1; visibility: visible; transform: translateY(0); }
.submenu a { padding: .45rem 1rem; white-space: nowrap; }

/* Hero */
.hero {
  position: relative; min-height: 68vh; display: flex; align-items: center;
  color: #fff; overflow: hidden;
}
.hero-bg {
  position: absolute; inset: 0; z-index: 0;
  background: url('/assets/images/hero-main-1920.webp') center 62%/cover no-repeat;
}
@media (max-width: 1200px) {
  .hero-bg { background-image: url('/assets/images/hero-main-1200.webp'); }
}
@media (max-width: 800px) {
  .hero-bg { background-image: url('/assets/images/hero-main-800.webp'); }
}
.hero::before {
  content: ""; position: absolute; inset: 0; z-index: 1;
  background: linear-gradient(90deg, rgba(5,22,38,.94) 0%, rgba(6,32,54,.82) 42%, rgba(6,32,54,.35) 75%, rgba(6,32,54,.15) 100%);
}
.hero-inner { position: relative; z-index: 2; padding: 4.5rem 0; }
.hero-eyebrow {
  display: flex; align-items: center; gap: .7rem;
  margin: 0 0 1.1rem; font-size: .95rem; letter-spacing: .18em;
  color: #8fc1e9; font-weight: 600;
}
.hero-eyebrow::before {
  content: ""; width: 36px; height: 3px; background: #3d9be9; flex: none;
}
.hero-inner h1 {
  font-size: clamp(2.4rem, 5.5vw, 3.9rem); margin: 0 0 1.1rem;
  font-weight: 700; letter-spacing: .06em;
  text-shadow: 0 2px 14px rgba(0,0,0,.35);
}
.hero-lead {
  font-size: clamp(1rem, 1.6vw, 1.2rem); line-height: 1.85; margin: 0;
  max-width: 620px; color: #d9e6f2;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: .9rem; margin-top: 2rem; }
.hero-actions .btn { margin-top: 0; padding: .8rem 2rem; font-size: 1.02rem; }
.btn-outline {
  background: transparent; border: 1px solid rgba(255,255,255,.7); color: #fff;
}
.btn-outline:hover, .btn-outline:focus { background: rgba(255,255,255,.14); color: #fff; }
.hero-points {
  display: flex; flex-wrap: wrap; gap: 1.5rem 3rem;
  list-style: none; margin: 2.6rem 0 0; padding: 1.4rem 0 0;
  border-top: 1px solid rgba(255,255,255,.28); max-width: 620px;
}
.hero-points li { display: flex; flex-direction: column; }
.hero-points strong { font-size: 1.5rem; color: #fff; letter-spacing: .03em; }
.hero-points span { font-size: .88rem; color: #a9c4da; margin-top: .15rem; }

/* Sections */
section { padding: 4rem 0; }
.section-title { text-align: center; font-size: 1.9rem; margin: 0 0 2.5rem; color: var(--color-primary-dark); }

.section-header { display: flex; align-items: baseline; justify-content: space-between; margin-bottom: 1.5rem; }
.section-header h2 { font-size: 1.7rem; color: var(--color-primary-dark); margin: 0; }
.more-link { font-size: .95rem; }

/* News */
.news-section { background: var(--color-bg-alt); }
.news-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; }
.news-card {
  position: relative; min-height: 280px; border-radius: var(--radius); overflow: hidden;
  background-size: cover; background-position: center;
}
.news-card::before {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(180deg, rgba(0,0,0,.12) 0%, rgba(0,0,0,.62) 100%);
}
.news-card-link {
  position: absolute; inset: 0; display: flex; align-items: flex-end; padding: 1.25rem;
  color: #fff; text-decoration: none; z-index: 2;
}
.news-card-link:hover, .news-card-link:focus { color: #fff; }
.news-card-link:hover .news-card-title, .news-card-link:focus .news-card-title { text-decoration: underline; }
.news-card-title {
  font-size: 1.05rem; font-weight: 600; line-height: 1.4;
  display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden;
}

/* About */
.about-section { background: #fff; }
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 3rem; align-items: center; }
.about-text h2 { font-size: 1.8rem; color: var(--color-primary-dark); margin: 0 0 1rem; }
.about-text p { color: var(--color-text-light); margin: 0 0 1rem; }
.about-media { margin: 0; }
.about-media img { border-radius: var(--radius); box-shadow: var(--shadow); }

.btn {
  display: inline-block; padding: .7rem 1.4rem; background: var(--color-primary); color: #fff;
  text-decoration: none; border-radius: var(--radius); margin-top: .5rem;
}
.btn:hover, .btn:focus { background: var(--color-primary-dark); color: #fff; }

/* Products / Applications */
.card-grid { display: grid; gap: 1.25rem; }
.grid-5 { grid-template-columns: repeat(5, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.card {
  background: #fff; border: 1px solid #e5e8eb; border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow); transition: transform .15s, box-shadow .15s;
}
.card:hover { transform: translateY(-3px); box-shadow: 0 8px 24px rgba(0,0,0,.1); }
.card img { width: 100%; aspect-ratio: 4/3; object-fit: cover; }
.product-card img { aspect-ratio: 2/3; object-fit: cover; }
.card h3 { margin: 0; font-size: 1rem; }
.card h3 a {
  display: block; padding: .9rem 1rem; color: var(--color-text); text-decoration: none;
}
.card h3 a:hover, .card h3 a:focus { color: var(--color-primary); }

.applications-section { background: var(--color-bg-alt); }

/* Contact */
.contact-section { background: #fff; }
.contact-info h2 { font-size: 1.8rem; color: var(--color-primary-dark); margin: 0 0 .5rem; }
.lead { font-size: 1.15rem; color: var(--color-text-light); margin: 0 0 1.5rem; }
.contact-list { display: grid; grid-template-columns: auto 1fr; gap: .75rem 1.25rem; margin: 0; }
.contact-list dt { font-weight: 600; color: var(--color-text-light); }
.contact-list dd { margin: 0; }
.contact-list a { color: var(--color-primary); text-decoration: none; }
.contact-list a:hover { text-decoration: underline; }
.contact-media { margin: 0; }
.contact-media > img { border-radius: var(--radius); box-shadow: var(--shadow); }
.contact-media figcaption { display: flex; align-items: center; gap: 1rem; margin-top: 1rem; }
.contact-media figcaption img { width: 96px; height: 96px; border-radius: var(--radius); }
.contact-media figcaption span { color: var(--color-text-light); font-size: .95rem; }

/* Footer */
.site-footer { background: #0a1c2b; color: #cfd8e0; padding: 1.75rem 0; font-size: .92rem; }
.footer-inner { text-align: center; }
.footer-inner p { margin: .25rem 0; }
.footer-inner a { color: #cfd8e0; }
.footer-inner a:hover { color: #fff; }

/* Mobile */
@media (max-width: 992px) {
  .grid-5 { grid-template-columns: repeat(3, 1fr); }
  .grid-4 { grid-template-columns: repeat(3, 1fr); }
  .news-grid { grid-template-columns: repeat(2, 1fr); }
  .two-col { grid-template-columns: 1fr; gap: 2rem; }
}

@media (max-width: 768px) {
  .nav-toggle { display: flex; }
  .primary-nav {
    position: fixed; inset: var(--header-height) 0 auto 0; background: #fff;
    border-bottom: 1px solid #e5e8eb; max-height: 0; overflow: hidden; transition: max-height .25s ease;
  }
  .primary-nav.is-open { max-height: calc(100vh - var(--header-height)); overflow-y: auto; }
  .nav-list { flex-direction: column; padding: .5rem 1rem; }
  .submenu { position: static; opacity: 1; visibility: visible; transform: none; box-shadow: none; border: 0; padding: 0 0 0 1rem; display: none; }
  .submenu-toggle[aria-expanded="true"] + .submenu { display: block; }
  .has-submenu:hover .submenu { display: none; }
  .has-submenu:hover .submenu-toggle[aria-expanded="true"] + .submenu { display: block; }
  .grid-5 { grid-template-columns: repeat(2, 1fr); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .news-grid { grid-template-columns: 1fr; }
  .contact-list { grid-template-columns: 1fr; }
  .contact-list dt { margin-top: .75rem; }
}

@media (max-width: 480px) {
  .grid-5, .grid-4 { grid-template-columns: 1fr; }
  .hero-inner { padding: 3.2rem 0; }
  .hero-points { gap: 1.1rem 2rem; }
  .hero-actions .btn { width: 100%; text-align: center; }
}

/* Visual revision: navigation, full-card links, grid and shared QR footer */
.nav-list { align-items: stretch; }
.nav-list > li { display: flex; align-items: stretch; }
.nav-list > li > a,
.nav-list > li > .submenu-toggle {
  display: flex; align-items: center; min-height: 44px;
  padding: .55rem .85rem; line-height: 1.25;
}
.nav-link-with-toggle .submenu-parent-link { padding-right: .25rem; }
.nav-link-with-toggle .submenu-caret { padding-left: .25rem; padding-right: .55rem; }
a:focus-visible,
button:focus-visible { outline: 3px solid var(--color-accent); outline-offset: 2px; }

.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.card-full-link {
  display: flex; flex-direction: column; height: 100%;
  color: var(--color-text); text-decoration: none;
}
.card-full-link h3 { padding: .9rem 1rem; }
.card-full-link:hover h3,
.card-full-link:focus-visible h3 { color: var(--color-primary); }
.card-full-link:focus-visible { outline-offset: -3px; }

.footer-inner {
  display: flex; align-items: center; justify-content: center;
  gap: 2rem; text-align: left;
}
.footer-copy { min-width: 0; }
.footer-contact { font-size: .88rem; line-height: 1.7; min-width: 0; }
.footer-contact p { margin: .1rem 0; white-space: nowrap; }
.footer-qr { display: flex; align-items: center; gap: .75rem; white-space: nowrap; }
.footer-qr img {
  width: 88px; height: 88px; padding: 4px; object-fit: contain;
  background: #fff; border-radius: 5px;
}
.footer-qr span { font-size: .88rem; }

@media (max-width: 992px) {
  .grid-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 768px) {
  .nav-list > li { display: block; }
  .nav-link-with-toggle {
    display: grid !important; grid-template-columns: minmax(0, 1fr) auto;
  }
  .nav-link-with-toggle > .submenu-parent-link { padding-right: .5rem; }
  .nav-link-with-toggle > .submenu-caret { justify-content: center; min-width: 44px; padding: .55rem; }
  .nav-link-with-toggle > .submenu { grid-column: 1 / -1; width: 100%; }
  .footer-inner { flex-direction: column; gap: .85rem; text-align: center; }
  .footer-contact p { white-space: normal; }
  .footer-qr { flex-direction: column; gap: .35rem; }
  .footer-qr img { width: 84px; height: 84px; }
}
@media (max-width: 480px) {
  .grid-3 { grid-template-columns: 1fr; }
}