:root {
  --bg: #f4f8fd;
  --text: #16324a;
  --muted: #587089;
  --primary: #0a74af;
  --primary-dark: #085d8d;
  --surface: #ffffff;
  --line: #d9e5f2;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  line-height: 1.65;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: inherit;
  text-decoration: none;
}

.container {
  width: min(1120px, 92vw);
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}

.site-header.scrolled {
  box-shadow: 0 8px 24px rgba(11, 46, 78, 0.08);
}

.nav-wrap {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.logo img {
  width: 146px;
  height: auto;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 18px;
  font-size: 14px;
  color: var(--muted);
}

.site-nav a {
  padding: 6px 2px;
  border-bottom: 2px solid transparent;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--primary);
  border-color: var(--primary);
}

.menu-toggle {
  display: none;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--text);
  border-radius: 10px;
  padding: 8px 10px;
  font-size: 14px;
}

.hero {
  position: relative;
  overflow: hidden;
  min-height: 76vh;
  display: flex;
  align-items: center;
}

.hero-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-mask {
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(8, 35, 61, 0.84) 0%, rgba(8, 35, 61, 0.56) 48%, rgba(8, 35, 61, 0.22) 100%);
}

.hero-content {
  position: relative;
  z-index: 1;
  color: #eaf4ff;
  padding: 64px 0;
  max-width: 760px;
}

.hero-kicker {
  margin: 0 0 12px;
  font-size: 13px;
  letter-spacing: 0.08em;
  opacity: 0.9;
}

.hero h1 {
  margin: 0;
  font-size: clamp(34px, 4.8vw, 54px);
  line-height: 1.2;
}

.hero-desc {
  margin: 18px 0 0;
  max-width: 640px;
  color: #d7e9f8;
  font-size: 18px;
}

.hero-actions {
  margin-top: 28px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  padding: 11px 22px;
  font-size: 14px;
  font-weight: 600;
  transition: all 0.2s ease;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--primary-dark);
}

.btn-secondary {
  border: 1px solid rgba(255, 255, 255, 0.55);
  color: #fff;
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.12);
}

.metrics {
  margin-top: -42px;
  position: relative;
  z-index: 2;
}

.metrics-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.metric-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 18px;
  box-shadow: 0 14px 30px rgba(8, 58, 95, 0.08);
}

.metric-card h3 {
  margin: 0;
  color: var(--primary);
  font-size: 30px;
  line-height: 1.2;
}

.metric-card p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.section {
  padding: 74px 0;
}

.section-alt {
  background: #edf4fb;
}

.section-label {
  margin: 0 0 10px;
  font-size: 13px;
  color: var(--primary);
  letter-spacing: 0.08em;
}

.section h2 {
  margin: 0;
  font-size: clamp(27px, 3.5vw, 38px);
  line-height: 1.25;
}

.split {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 30px;
  align-items: center;
}

.media-card {
  border-radius: 16px;
  overflow: hidden;
  border: 1px solid var(--line);
  box-shadow: 0 16px 36px rgba(8, 58, 95, 0.1);
}

.timeline {
  margin-top: 24px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.timeline article {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 16px;
}

.timeline h3 {
  margin: 0;
  color: var(--primary);
  font-size: 22px;
}

.timeline p {
  margin: 6px 0 0;
  color: var(--muted);
}

.rd-grid,
.products-grid {
  margin-top: 24px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.rd-card,
.product-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 16px;
}

.rd-card img {
  border-radius: 10px;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.rd-card h3,
.product-card h3 {
  margin: 12px 0 4px;
  font-size: 20px;
}

.rd-card p,
.product-card p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.clients-grid {
  margin-top: 24px;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
}

.clients-grid img {
  width: 100%;
  height: 110px;
  object-fit: contain;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: var(--surface);
  padding: 12px;
}

.clients-text {
  margin: 16px 0 0;
  color: var(--muted);
}

.section-contact {
  padding-top: 30px;
}

.contact-box {
  background: linear-gradient(120deg, #e8f4ff 0%, #f8fcff 100%);
  border: 1px solid #cfe4f7;
  border-radius: 16px;
  padding: 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.contact-box h2 {
  margin-bottom: 10px;
}

.contact-box p {
  margin: 0;
  color: var(--muted);
}

.site-footer {
  background: #0f3552;
  color: #d4e8f8;
}

.footer-wrap {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.footer-wrap p {
  margin: 0;
}

.footer-wrap a {
  color: #fff;
}

@media (max-width: 980px) {
  .metrics-grid,
  .timeline,
  .rd-grid,
  .products-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .split {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 760px) {
  .menu-toggle {
    display: inline-flex;
  }
  .site-nav {
    position: absolute;
    left: 4vw;
    right: 4vw;
    top: calc(100% + 6px);
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 12px;
    box-shadow: 0 12px 28px rgba(7, 40, 67, 0.15);
    padding: 10px;
    flex-direction: column;
    align-items: flex-start;
    display: none;
  }
  .site-nav.open {
    display: flex;
  }
  .hero {
    min-height: 68vh;
  }
  .hero-desc {
    font-size: 16px;
  }
  .clients-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .contact-box {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 520px) {
  .metrics-grid,
  .timeline,
  .rd-grid,
  .products-grid {
    grid-template-columns: 1fr;
  }
  .section {
    padding: 58px 0;
  }
}