:root {
  color-scheme: light;
  --ink: #14212b;
  --muted: #5d6b76;
  --line: #dce5eb;
  --panel: #ffffff;
  --surface: #f3f7f8;
  --accent: #0a7f86;
  --accent-strong: #075f64;
  --accent-soft: #dff3f2;
  --deep: #0d222b;
  --white: #ffffff;
  --shadow: 0 18px 45px rgba(20, 33, 43, 0.12);
  --max: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", Arial, sans-serif;
  color: var(--ink);
  background: var(--white);
  line-height: 1.7;
}

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

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

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 18px clamp(20px, 5vw, 64px);
  color: var(--white);
  transition: background-color 180ms ease, box-shadow 180ms ease, color 180ms ease;
}

.site-header.is-scrolled,
.site-header.is-open {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 10px 28px rgba(20, 33, 43, 0.1);
  backdrop-filter: blur(12px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  font-weight: 700;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border: 1px solid rgba(255, 255, 255, 0.5);
  border-radius: 8px;
  background: rgba(10, 127, 134, 0.9);
  color: var(--white);
  font-size: 15px;
}

.brand-name {
  overflow: hidden;
  max-width: 360px;
  white-space: nowrap;
  text-overflow: ellipsis;
  font-size: 16px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 22px;
  font-size: 14px;
}

.site-nav a {
  opacity: 0.92;
}

.site-nav a:hover {
  opacity: 1;
}

.nav-action {
  padding: 9px 14px;
  border: 1px solid currentColor;
  border-radius: 8px;
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: 0;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.15);
  color: currentColor;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  margin: 6px auto;
  background: currentColor;
}

.hero {
  min-height: 100vh;
  display: grid;
  align-items: center;
  padding: 132px clamp(20px, 6vw, 76px) 72px;
  color: var(--white);
  background:
    linear-gradient(90deg, rgba(9, 22, 30, 0.94) 0%, rgba(9, 22, 30, 0.78) 32%, rgba(9, 22, 30, 0.22) 72%),
    url("/assets/hero-data-annotation.png") center / cover no-repeat;
}

.hero-content {
  width: min(760px, 100%);
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
}

.hero .eyebrow {
  color: #72d0d2;
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1 {
  margin: 0;
  max-width: 740px;
  font-size: clamp(42px, 6vw, 72px);
  line-height: 1.08;
}

h2 {
  margin: 0;
  font-size: clamp(30px, 4vw, 46px);
  line-height: 1.18;
}

h3 {
  margin: 0;
  font-size: 20px;
  line-height: 1.35;
}

.hero-copy {
  max-width: 680px;
  margin: 24px 0 0;
  color: rgba(255, 255, 255, 0.88);
  font-size: 18px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 34px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 11px 20px;
  border-radius: 8px;
  font-weight: 700;
}

.button.primary {
  background: var(--accent);
  color: var(--white);
}

.button.primary:hover {
  background: var(--accent-strong);
}

.button.secondary {
  border: 1px solid rgba(255, 255, 255, 0.75);
  color: var(--white);
}

.hero-metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  max-width: 720px;
  margin: 44px 0 0;
}

.hero-metrics div {
  padding: 18px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(8px);
}

.hero-metrics dt {
  margin: 0;
  font-size: 20px;
  font-weight: 800;
}

.hero-metrics dd {
  margin: 6px 0 0;
  color: rgba(255, 255, 255, 0.78);
  font-size: 13px;
}

.section {
  padding: 96px clamp(20px, 6vw, 76px);
}

.section > * {
  max-width: var(--max);
  margin-left: auto;
  margin-right: auto;
}

.section-heading {
  display: grid;
  gap: 16px;
  margin-bottom: 42px;
}

.section-heading p:last-child,
.split p,
.rich-text p,
.contact-panel p {
  max-width: 760px;
  margin-top: 0;
  margin-bottom: 0;
  color: var(--muted);
  font-size: 17px;
}

.service-grid,
.security-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.service-card,
.security-grid article {
  min-height: 240px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.service-card p,
.security-grid p,
.timeline p,
.feature-list span {
  margin: 14px 0 0;
  color: var(--muted);
}

.card-index {
  display: inline-flex;
  margin-bottom: 22px;
  color: var(--accent);
  font-weight: 800;
}

.muted {
  background: var(--surface);
}

.timeline {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 16px;
}

.timeline article {
  position: relative;
  padding: 24px;
  border-radius: 8px;
  background: var(--white);
  box-shadow: var(--shadow);
}

.timeline span {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  margin-bottom: 18px;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-weight: 800;
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.78fr) minmax(0, 1fr);
  gap: 54px;
  align-items: start;
}

.split > * {
  max-width: none;
}

.feature-list {
  display: grid;
  gap: 14px;
}

.feature-list div {
  display: grid;
  gap: 8px;
  padding: 20px;
  border-left: 4px solid var(--accent);
  border-radius: 8px;
  background: var(--surface);
}

.dark {
  color: var(--white);
  background: var(--deep);
}

.dark .section-heading p:last-child,
.dark .security-grid p {
  color: rgba(255, 255, 255, 0.72);
}

.security-grid article {
  border-color: rgba(255, 255, 255, 0.14);
  background: rgba(255, 255, 255, 0.06);
}

.rich-text {
  display: grid;
  gap: 18px;
}

.contact-section {
  background: var(--surface);
}

.contact-panel {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(280px, 0.7fr);
  gap: 28px;
  padding: 34px;
  border-radius: 8px;
  background: var(--white);
  box-shadow: var(--shadow);
}

.contact-list {
  display: grid;
  gap: 12px;
}

.contact-list a,
.contact-list span {
  display: block;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--ink);
  background: var(--white);
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px 24px;
  padding: 26px clamp(20px, 6vw, 76px);
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 14px;
}

.site-footer p {
  margin: 0;
}

.site-footer a {
  color: var(--accent-strong);
  font-weight: 700;
}

@media (max-width: 1060px) {
  .service-grid,
  .timeline,
  .security-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 820px) {
  .site-header {
    padding: 14px 18px;
  }

  .brand-name {
    max-width: 230px;
  }

  .nav-toggle {
    display: block;
  }

  .site-nav {
    position: absolute;
    top: 72px;
    left: 18px;
    right: 18px;
    display: none;
    align-items: stretch;
    flex-direction: column;
    gap: 0;
    padding: 10px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--white);
    color: var(--ink);
    box-shadow: var(--shadow);
  }

  .site-nav.is-open {
    display: flex;
  }

  .site-nav a {
    padding: 12px;
  }

  .nav-action {
    border-color: var(--line);
  }

  .hero {
    min-height: auto;
    padding-top: 118px;
    background:
      linear-gradient(90deg, rgba(9, 22, 30, 0.95), rgba(9, 22, 30, 0.72)),
      url("/assets/hero-data-annotation.png") center / cover no-repeat;
  }

  h1 {
    font-size: 40px;
  }

  .hero-metrics,
  .service-grid,
  .timeline,
  .security-grid,
  .split,
  .contact-panel {
    grid-template-columns: 1fr;
  }

  .section {
    padding-top: 72px;
    padding-bottom: 72px;
  }
}

@media (max-width: 520px) {
  .brand-name {
    max-width: 180px;
    font-size: 14px;
  }

  .hero-actions {
    display: grid;
  }

  .button {
    width: 100%;
  }

  h1 {
    font-size: 34px;
  }

  h2 {
    font-size: 28px;
  }
}