:root {
  --bg: #f7f9fc;
  --paper: #ffffff;
  --ink: #0f172a;
  --muted: #586477;
  --line: #dbe3ef;
  --blue: #0b4d9c;
  --blue-dark: #073a75;
  --teal: #158083;
  --teal-soft: #e7f5f4;
  --shadow: 0 18px 45px rgba(15, 23, 42, 0.08);
  --max: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB", "Segoe UI", Arial, sans-serif;
  letter-spacing: 0;
}

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

a:hover {
  color: var(--blue);
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 24px;
  min-height: 72px;
  padding: 0 max(24px, calc((100vw - var(--max)) / 2));
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid rgba(219, 227, 239, 0.86);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  justify-self: start;
  color: var(--ink);
  font-size: 18px;
  font-weight: 800;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: 8px;
  background: var(--blue);
  color: #fff;
  font-size: 17px;
  line-height: 1;
}

.nav {
  display: flex;
  align-items: center;
  gap: 32px;
  color: var(--muted);
  font-size: 15px;
  font-weight: 650;
}

.nav a {
  padding: 26px 0 23px;
  border-bottom: 3px solid transparent;
}

.nav a:hover {
  border-color: var(--blue);
}

.header-link {
  justify-self: end;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--blue-dark);
  font-size: 14px;
  font-weight: 750;
}

main {
  overflow: hidden;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.88fr) minmax(360px, 1.12fr);
  gap: 42px;
  align-items: center;
  max-width: var(--max);
  min-height: clamp(640px, calc(100vh - 150px), 790px);
  margin: 0 auto;
  padding: 58px 24px 50px;
}

.hero-copy {
  min-width: 0;
}

.hero h1 {
  max-width: 660px;
  margin: 0 0 22px;
  font-size: clamp(48px, 7vw, 88px);
  line-height: 1.04;
  font-weight: 900;
}

.hero-lead {
  max-width: 590px;
  margin: 0;
  color: #2e394a;
  font-size: clamp(18px, 2.2vw, 24px);
  line-height: 1.72;
  font-weight: 500;
}

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

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 800;
}

.button.primary {
  background: var(--blue);
  color: #fff;
  box-shadow: 0 14px 28px rgba(11, 77, 156, 0.18);
}

.button.primary:hover {
  background: var(--blue-dark);
  color: #fff;
}

.button.secondary {
  border: 1px solid #9db3d3;
  background: #fff;
  color: var(--blue-dark);
}

.identity-strip {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0;
  max-width: 620px;
  margin: 42px 0 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.identity-strip div {
  padding: 18px 18px 18px 0;
}

.identity-strip div + div {
  padding-left: 18px;
  border-left: 1px solid var(--line);
}

.identity-strip dt {
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 750;
}

.identity-strip dd {
  margin: 0;
  color: var(--ink);
  font-size: 16px;
  font-weight: 850;
}

.hero-visual {
  position: relative;
  margin: 0;
}

.hero-visual img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.section {
  max-width: var(--max);
  margin: 0 auto;
  padding: 78px 24px;
}

.section + .section {
  border-top: 1px solid var(--line);
}

.section-heading {
  display: grid;
  grid-template-columns: minmax(230px, 0.44fr) minmax(0, 0.56fr);
  gap: 40px;
  align-items: start;
  margin-bottom: 34px;
}

.section-heading h2,
.ai-panel h2 {
  margin: 0;
  font-size: clamp(28px, 3.5vw, 42px);
  line-height: 1.16;
  font-weight: 900;
}

.section-heading p,
.ai-panel p {
  margin: 0;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.85;
}

.entity-table {
  overflow: hidden;
  border-top: 2px solid var(--ink);
  background: var(--paper);
}

.entity-table div {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 28px;
  padding: 18px 24px;
  border-bottom: 1px solid var(--line);
}

.entity-table span {
  color: var(--blue-dark);
  font-size: 15px;
  font-weight: 850;
}

.entity-table strong {
  color: #263247;
  font-size: 16px;
  font-weight: 650;
  line-height: 1.8;
}

.split-section {
  display: grid;
  grid-template-columns: minmax(250px, 0.33fr) minmax(0, 0.67fr);
  gap: 62px;
  align-items: start;
}

.split-section .section-heading {
  display: block;
  margin-bottom: 0;
}

.sticky-heading {
  position: sticky;
  top: 110px;
}

.sticky-heading h2 {
  margin-bottom: 18px;
}

.principle-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.principle-list article,
.topic-grid article {
  min-height: 210px;
  padding: 30px;
  background: var(--paper);
}

.principle-list h3,
.topic-grid h3 {
  margin: 20px 0 12px;
  font-size: 22px;
  line-height: 1.28;
}

.principle-list p,
.topic-grid p {
  margin: 0;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.8;
}

.icon {
  display: block;
  position: relative;
  width: 42px;
  height: 42px;
  color: var(--blue);
}

.icon::before,
.icon::after {
  position: absolute;
  content: "";
}

.icon.microscope::before {
  left: 8px;
  top: 4px;
  width: 15px;
  height: 28px;
  border: 3px solid currentColor;
  border-radius: 8px;
  transform: rotate(28deg);
}

.icon.microscope::after {
  left: 3px;
  bottom: 4px;
  width: 34px;
  height: 14px;
  border-left: 3px solid currentColor;
  border-bottom: 3px solid currentColor;
}

.icon.trend::before {
  left: 5px;
  bottom: 6px;
  width: 28px;
  height: 24px;
  border-left: 3px solid currentColor;
  border-bottom: 3px solid currentColor;
}

.icon.trend::after {
  left: 13px;
  top: 10px;
  width: 22px;
  height: 22px;
  border-top: 3px solid currentColor;
  border-right: 3px solid currentColor;
  transform: rotate(-10deg);
}

.icon.network::before {
  left: 6px;
  top: 7px;
  width: 29px;
  height: 29px;
  border: 3px solid currentColor;
  border-radius: 50%;
}

.icon.network::after {
  left: 5px;
  top: 18px;
  width: 32px;
  height: 3px;
  background: currentColor;
  box-shadow: 16px -12px 0 -1px currentColor, 4px 17px 0 -1px currentColor;
  transform: rotate(30deg);
}

.icon.document::before {
  inset: 4px 8px 4px 10px;
  border: 3px solid currentColor;
  border-radius: 4px;
}

.icon.document::after {
  left: 17px;
  top: 15px;
  width: 14px;
  height: 3px;
  background: currentColor;
  box-shadow: 0 8px 0 currentColor, 0 16px 0 currentColor;
}

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

.topic-grid article {
  border: 1px solid var(--line);
  border-radius: 8px;
}

.topic-grid article:nth-child(2) {
  background: #f8fcfc;
  border-color: #cde9e7;
}

.topic-grid h3 {
  margin-top: 0;
  color: var(--blue-dark);
}

.ai-section {
  max-width: none;
  padding-left: max(24px, calc((100vw - var(--max)) / 2));
  padding-right: max(24px, calc((100vw - var(--max)) / 2));
  background: #0b223d;
}

.ai-panel {
  display: grid;
  grid-template-columns: minmax(280px, 0.42fr) minmax(0, 0.58fr);
  gap: 58px;
  align-items: start;
  max-width: var(--max);
  margin: 0 auto;
  color: #fff;
}

.ai-panel p {
  color: #c3d2e4;
  margin-top: 18px;
}

.ai-panel ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.ai-panel li {
  position: relative;
  padding: 18px 0 18px 34px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.16);
  color: #e9f2ff;
  font-size: 17px;
  line-height: 1.72;
}

.ai-panel li::before {
  position: absolute;
  left: 0;
  top: 26px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--teal);
  content: "";
}

.faq-list {
  border-top: 2px solid var(--ink);
  background: var(--paper);
}

.faq-list details {
  border-bottom: 1px solid var(--line);
}

.faq-list summary {
  cursor: pointer;
  padding: 22px 24px;
  color: var(--blue-dark);
  font-size: 17px;
  font-weight: 850;
}

.faq-list p {
  margin: 0;
  padding: 0 24px 24px;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.85;
}

.footer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 36px;
  align-items: end;
  padding: 46px max(24px, calc((100vw - var(--max)) / 2));
  background: #081a30;
  color: #eaf2fc;
}

.footer strong {
  font-size: 18px;
}

.footer p {
  max-width: 820px;
  margin: 12px 0 0;
  color: #b9c9dc;
  font-size: 15px;
  line-height: 1.8;
}

.footer-links {
  display: flex;
  gap: 24px;
  color: #d8e8fb;
  font-size: 14px;
  font-weight: 750;
}

@media (max-width: 920px) {
  .site-header {
    grid-template-columns: 1fr auto;
    gap: 16px;
    min-height: auto;
    padding: 14px 20px;
  }

  .nav {
    grid-column: 1 / -1;
    justify-content: space-between;
    gap: 16px;
    width: 100%;
    overflow-x: auto;
    padding-top: 4px;
  }

  .nav a {
    padding: 8px 0 10px;
    white-space: nowrap;
  }

  .header-link {
    min-height: 36px;
    padding: 0 12px;
  }

  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
    padding-top: 40px;
  }

  .hero-visual {
    order: -1;
  }

  .section-heading,
  .split-section,
  .ai-panel {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .sticky-heading {
    position: static;
  }

  .topic-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .footer {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .brand {
    font-size: 16px;
  }

  .brand-mark {
    width: 30px;
    height: 30px;
  }

  .header-link {
    font-size: 13px;
  }

  .hero {
    padding: 28px 18px 42px;
  }

  .hero h1 {
    font-size: 48px;
  }

  .hero-lead {
    font-size: 18px;
  }

  .button {
    width: 100%;
  }

  .identity-strip {
    grid-template-columns: 1fr;
  }

  .identity-strip div,
  .identity-strip div + div {
    padding: 16px 0;
    border-left: 0;
    border-top: 1px solid var(--line);
  }

  .identity-strip div:first-child {
    border-top: 0;
  }

  .section {
    padding: 56px 18px;
  }

  .entity-table div {
    grid-template-columns: 1fr;
    gap: 6px;
    padding: 18px;
  }

  .principle-list,
  .topic-grid {
    grid-template-columns: 1fr;
  }

  .principle-list article,
  .topic-grid article {
    min-height: auto;
    padding: 24px;
  }

  .ai-section {
    padding: 56px 18px;
  }

  .footer {
    padding: 38px 18px;
  }

  .footer-links {
    flex-wrap: wrap;
  }
}