:root {
  --navy: #0b1f4d;
  --blue: #2963ea;
  --blue-dark: #1749c7;
  --orange: #ff6a2b;
  --ink: #17223d;
  --muted: #64718a;
  --line: #e5eaf3;
  --surface: #f5f8ff;
  --white: #ffffff;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

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

button,
input {
  font: inherit;
}

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

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

.container {
  width: min(1180px, calc(100% - 40px));
  margin-inline: auto;
}

.container.narrow {
  max-width: 760px;
}

.site-header {
  position: sticky;
  z-index: 50;
  top: 0;
  border-bottom: 1px solid rgba(229, 234, 243, 0.9);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(15px);
}

.header-inner {
  display: flex;
  min-height: 76px;
  align-items: center;
  justify-content: space-between;
}

.logo {
  color: var(--navy);
  font-size: 29px;
  font-weight: 900;
  letter-spacing: -1.8px;
}

.logo span {
  color: var(--orange);
}

.desktop-nav {
  display: flex;
  gap: 46px;
}

.desktop-nav a,
.mobile-nav a {
  position: relative;
  color: #27324b;
  font-size: 16px;
  font-weight: 700;
}

.desktop-nav a::after {
  position: absolute;
  right: 0;
  bottom: -27px;
  left: 0;
  height: 3px;
  border-radius: 999px;
  background: var(--blue);
  content: "";
  opacity: 0;
  transform: scaleX(0.5);
  transition: 180ms ease;
}

.desktop-nav a:hover,
.desktop-nav a.active,
.mobile-nav a.active {
  color: var(--blue);
}

.desktop-nav a.active::after {
  opacity: 1;
  transform: scaleX(1);
}

.menu-button {
  display: none;
  min-width: 58px;
  height: 43px;
  padding: 0 12px;
  border: 0;
  border-radius: 12px;
  color: var(--navy);
  background: var(--surface);
  cursor: pointer;
  font-size: 13px;
  font-weight: 800;
}

.mobile-nav {
  display: none;
}

.hero {
  overflow: hidden;
  padding: 52px 0 44px;
  background:
    radial-gradient(circle at 12% 23%, rgba(41, 99, 234, 0.08), transparent 23%),
    #fff;
}

.hero-grid {
  display: grid;
  min-height: 530px;
  align-items: center;
  grid-template-columns: 0.88fr 1.12fr;
  gap: 54px;
}

.kicker,
.section-label {
  color: var(--blue);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 1.5px;
}

.hero-copy h1 {
  margin: 18px 0 0;
  color: var(--navy);
  font-size: clamp(49px, 5vw, 72px);
  font-weight: 900;
  line-height: 1.12;
  letter-spacing: -4px;
}

.hero-copy h1 span {
  color: var(--blue);
}

.hero-text {
  max-width: 520px;
  margin: 26px 0 0;
  color: #53617b;
  font-size: 18px;
  line-height: 1.9;
}

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

.button {
  display: inline-flex;
  min-height: 52px;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 0 27px;
  border: 1px solid transparent;
  border-radius: 15px;
  font-weight: 800;
  transition:
    transform 180ms ease,
    box-shadow 180ms ease,
    background 180ms ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button.primary {
  color: white;
  background: var(--blue);
  box-shadow: 0 12px 28px rgba(41, 99, 234, 0.22);
}

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

.button.secondary {
  border-color: #c9d5eb;
  color: var(--navy);
  background: white;
}

.button.white {
  position: relative;
  z-index: 2;
  color: var(--blue);
  background: white;
}

.trust-row {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin-top: 27px;
  color: #79859a;
  font-size: 13px;
  font-weight: 700;
}

.trust-row span::before {
  display: inline-block;
  width: 6px;
  height: 6px;
  margin-right: 7px;
  border-radius: 50%;
  background: #45b883;
  content: "";
  vertical-align: 2px;
}

.hero-art {
  position: relative;
  min-height: 510px;
  overflow: hidden;
  border-radius: 42% 10% 18% 38% / 38% 12% 18% 34%;
  background: var(--navy);
  box-shadow: 0 28px 70px rgba(12, 36, 88, 0.18);
}

.hero-art > img {
  width: 100%;
  height: 510px;
  object-fit: cover;
}

.knowledge-badge {
  position: absolute;
  right: 24px;
  bottom: 24px;
  display: flex;
  width: 112px;
  height: 112px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(255, 255, 255, 0.42);
  border-radius: 50%;
  color: white;
  background: rgba(17, 48, 116, 0.77);
  backdrop-filter: blur(12px);
}

.knowledge-badge strong {
  font-size: 26px;
}

.knowledge-badge span {
  font-size: 12px;
}

.category-band {
  border-block: 1px solid var(--line);
}

.category-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
}

.category-grid a {
  display: flex;
  min-height: 94px;
  align-items: center;
  justify-content: center;
  border-right: 1px solid var(--line);
  border-top: 4px solid transparent;
  transition: 180ms ease;
}

.category-grid a:nth-child(1) { border-top-color: #4775ea; }
.category-grid a:nth-child(2) { border-top-color: #43b27b; }
.category-grid a:nth-child(3) { border-top-color: #f27850; }
.category-grid a:nth-child(4) { border-top-color: #f1b436; }
.category-grid a:nth-child(5) { border-top-color: #8a66dc; }
.category-grid a:nth-child(6) { border-top-color: #3bb6cd; }

.category-grid a:last-child {
  border-right: 0;
}

.category-grid a:hover {
  color: var(--blue);
  transform: translateY(-2px);
}

.category-grid span {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.category-grid strong {
  font-size: 14px;
}

.category-grid small {
  color: #8a94a7;
  font-size: 11px;
}

.section {
  padding: 90px 0;
}

.featured,
.values,
.related {
  background: #fbfcff;
}

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 30px;
  margin-bottom: 38px;
}

.section-head.compact {
  margin-bottom: 28px;
}

.section-head.centered {
  justify-content: center;
  text-align: center;
}

.section-head h2,
.question-panel h2,
.mission-panel h2 {
  margin: 8px 0 0;
  color: var(--navy);
  font-size: clamp(30px, 3vw, 42px);
  font-weight: 900;
  letter-spacing: -1.7px;
}

.section-head p {
  margin: 11px 0 0;
  color: var(--muted);
}

.text-link {
  color: var(--blue);
  font-size: 14px;
  font-weight: 800;
}

.text-link:hover {
  color: var(--orange);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 25px;
}

.science-card {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: white;
  transition:
    transform 200ms ease,
    box-shadow 200ms ease,
    border-color 200ms ease;
}

.science-card:hover {
  border-color: #cbd7ec;
  transform: translateY(-5px);
  box-shadow: 0 18px 40px rgba(24, 53, 110, 0.1);
}

.card-image {
  display: block;
  height: 228px;
  overflow: hidden;
  background: #eaf0fb;
}

.card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 450ms ease;
}

.science-card:hover .card-image img {
  transform: scale(1.035);
}

.card-body {
  padding: 23px 24px 25px;
}

.eyebrow {
  font-size: 12px;
  font-weight: 900;
}

.card-body h3 {
  min-height: 58px;
  margin: 10px 0 9px;
  color: var(--ink);
  font-size: 20px;
  line-height: 1.45;
}

.card-body h3 a:hover {
  color: var(--blue);
}

.card-body > p {
  min-height: 52px;
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.75;
}

.card-meta {
  display: flex;
  gap: 14px;
  margin: 17px 0;
  color: #8993a7;
  font-size: 12px;
}

.card-meta span + span::before {
  margin-right: 14px;
  content: "·";
}

.question-section {
  padding: 0 0 90px;
  background: #fbfcff;
}

.question-panel,
.mission-panel {
  position: relative;
  display: flex;
  min-height: 250px;
  overflow: hidden;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
  padding: 54px 62px;
  border-radius: 30px;
  color: white;
  background:
    radial-gradient(circle at 80% 12%, rgba(77, 136, 255, 0.7), transparent 28%),
    linear-gradient(135deg, #0b2459, #164db6);
}

.question-panel::after,
.mission-panel::after {
  position: absolute;
  top: -100px;
  right: 7%;
  width: 260px;
  height: 260px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 50%;
  content: "";
}

.question-panel h2,
.mission-panel h2 {
  color: white;
}

.question-panel p,
.mission-panel p {
  margin: 13px 0 0;
  color: #dbe6ff;
  line-height: 1.8;
}

.section-label.light {
  color: #bcd1ff;
}

.page-hero {
  padding: 86px 0 80px;
  text-align: center;
  background:
    radial-gradient(circle at 20% 40%, rgba(54, 105, 231, 0.12), transparent 24%),
    radial-gradient(circle at 84% 20%, rgba(255, 106, 43, 0.1), transparent 20%),
    #f7f9ff;
}

.page-hero h1,
.about-hero h1,
.article-header h1 {
  margin: 10px 0 0;
  color: var(--navy);
  font-size: clamp(42px, 5vw, 64px);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -3px;
}

.page-hero p {
  max-width: 620px;
  margin: 20px auto 0;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
}

.explorer-tools {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
  margin-bottom: 28px;
}

.search-box {
  display: flex;
  width: min(100%, 650px);
  height: 58px;
  align-items: center;
  gap: 12px;
  padding: 0 20px;
  border: 1px solid #dbe3f2;
  border-radius: 16px;
  color: #8792a7;
  background: white;
  box-shadow: 0 10px 30px rgba(29, 59, 115, 0.06);
}

.search-box:focus-within {
  border-color: var(--blue);
  box-shadow: 0 0 0 4px rgba(41, 99, 234, 0.1);
}

.search-box input {
  width: 100%;
  border: 0;
  outline: 0;
  color: var(--ink);
  background: transparent;
}

.filter-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}

.filter-row button {
  padding: 9px 17px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: #56627a;
  background: white;
  cursor: pointer;
}

.filter-row button:hover,
.filter-row button.selected {
  border-color: var(--blue);
  color: white;
  background: var(--blue);
}

.result-count {
  margin: 0 0 22px;
  color: #7d879b;
  font-size: 14px;
}

.empty-state {
  padding: 80px 20px;
  border: 1px dashed #cbd5e7;
  border-radius: 24px;
  text-align: center;
  background: #fafcff;
}

.empty-state h2 {
  color: var(--navy);
}

.empty-state p {
  color: var(--muted);
}

.article-page {
  padding: 58px 0 94px;
}

.article-header {
  max-width: 1020px;
}

.back-link {
  display: inline-block;
  margin-bottom: 44px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 700;
}

.back-link:hover {
  color: var(--blue);
}

.article-category {
  display: block;
  font-size: 14px;
  font-weight: 900;
}

.article-header h1 {
  max-width: 850px;
  font-size: clamp(38px, 5vw, 62px);
}

.article-summary {
  max-width: 750px;
  margin: 20px 0 16px;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.8;
}

.article-meta {
  display: flex;
  gap: 22px;
  color: #8a94a7;
  font-size: 13px;
  font-weight: 700;
}

.article-cover {
  height: min(55vw, 530px);
  min-height: 300px;
  overflow: hidden;
  margin-top: 38px;
  border-radius: 28px;
  background: #eaf0fb;
}

.article-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.article-layout {
  display: grid;
  max-width: 1020px;
  margin-top: 60px;
  align-items: start;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 68px;
}

.article-layout aside {
  position: sticky;
  top: 110px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 24px;
  border-radius: 18px;
  background: #eef4ff;
}

.article-layout aside span,
.fact-box span {
  color: var(--blue);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 1px;
}

.article-layout aside strong {
  color: var(--navy);
  font-size: 17px;
  line-height: 1.65;
}

.article-content {
  max-width: 680px;
}

.article-lead {
  margin-top: 0;
  color: #33415f;
  font-size: 20px !important;
  font-weight: 700;
  line-height: 1.9 !important;
}

.article-content section {
  margin-top: 48px;
}

.article-content h2 {
  margin: 0 0 18px;
  color: var(--navy);
  font-size: 28px;
}

.article-content p {
  color: #4f5d77;
  font-size: 17px;
  line-height: 2;
}

.fact-box {
  margin-top: 26px;
  padding: 24px 26px;
  border-left: 4px solid var(--orange);
  border-radius: 0 16px 16px 0;
  background: #fff6f0;
}

.fact-box span {
  color: var(--orange);
}

.fact-box p {
  margin: 8px 0 0;
  color: #5c4b43;
  font-size: 15px;
}

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

.about-hero {
  padding: 76px 0 90px;
}

.about-grid {
  display: grid;
  align-items: center;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 70px;
}

.about-hero h1 {
  font-size: clamp(40px, 4.6vw, 60px);
}

.about-hero p {
  margin: 24px 0 32px;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.9;
}

.about-art {
  min-height: 480px;
  overflow: hidden;
  border-radius: 30px;
  background: var(--navy);
}

.about-art img {
  width: 100%;
  height: 480px;
  object-fit: cover;
}

.value-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
}

.value-grid article {
  padding: 28px;
  border-top: 3px solid #e4eaf5;
  background: white;
}

.value-grid h3 {
  margin: 0 0 10px;
  color: var(--navy);
  font-size: 23px;
}

.value-grid p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.mission-section {
  padding: 90px 0;
}

.mission-panel {
  display: block;
  max-width: 920px;
  min-height: auto;
  text-align: center;
}

.mission-panel p {
  max-width: 680px;
  margin: 18px auto 0;
}

.not-found {
  display: grid;
  min-height: 65vh;
  padding: 80px 20px;
  place-items: center;
  text-align: center;
}

.not-found span {
  color: var(--blue);
  font-size: 70px;
  font-weight: 900;
}

.not-found h1 {
  color: var(--navy);
  font-size: 34px;
}

.not-found p {
  margin-bottom: 28px;
  color: var(--muted);
}

.site-footer {
  border-top: 1px solid var(--line);
  background: #f7f9fd;
}

.footer-inner {
  display: grid;
  min-height: 180px;
  align-items: center;
  grid-template-columns: 1fr auto auto;
  gap: 50px;
}

.footer-logo {
  font-size: 24px;
}

.footer-inner p {
  margin: 8px 0 0;
  color: #758096;
  font-size: 13px;
}

.footer-links {
  display: flex;
  gap: 26px;
  color: #44506a;
  font-size: 14px;
  font-weight: 700;
}

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

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  padding: 0;
  border: 0;
  margin: -1px;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
}

[hidden] {
  display: none !important;
}

@media (max-width: 1040px) {
  .hero-grid,
  .about-grid {
    grid-template-columns: 1fr 1fr;
    gap: 35px;
  }

  .category-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .category-grid a:nth-child(3) {
    border-right: 0;
  }

  .category-grid a:nth-child(-n + 3) {
    border-bottom: 1px solid var(--line);
  }

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

@media (max-width: 820px) {
  .desktop-nav {
    display: none;
  }

  .menu-button {
    display: block;
  }

  .mobile-nav {
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding: 8px 20px 18px;
    border-top: 1px solid var(--line);
    background: white;
  }

  .mobile-nav a {
    padding: 13px 10px;
    border-radius: 10px;
  }

  .mobile-nav a.active {
    background: var(--surface);
  }

  .hero {
    padding-top: 35px;
  }

  .hero-grid,
  .about-grid {
    grid-template-columns: 1fr;
  }

  .hero-copy {
    text-align: center;
  }

  .hero-text {
    margin-inline: auto;
  }

  .hero-actions,
  .trust-row {
    justify-content: center;
  }

  .hero-art {
    min-height: 470px;
    border-radius: 28px;
  }

  .hero-art > img {
    height: 470px;
  }

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

  .article-layout {
    grid-template-columns: 1fr;
    gap: 30px;
  }

  .article-layout aside {
    position: static;
  }

  .footer-inner {
    padding: 40px 0;
    grid-template-columns: 1fr;
    gap: 22px;
    text-align: center;
  }

  .footer-links {
    justify-content: center;
  }
}

@media (max-width: 580px) {
  .container {
    width: calc(100% - 28px);
  }

  .header-inner {
    min-height: 66px;
  }

  .logo {
    font-size: 25px;
  }

  .hero-grid {
    min-height: auto;
    gap: 35px;
  }

  .hero-copy h1 {
    font-size: 44px;
    letter-spacing: -2.5px;
  }

  .hero-text {
    font-size: 16px;
  }

  .hero-actions {
    flex-direction: column;
  }

  .button {
    width: 100%;
  }

  .hero-art,
  .hero-art > img {
    min-height: 360px;
    height: 360px;
  }

  .knowledge-badge {
    width: 88px;
    height: 88px;
  }

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

  .category-grid a {
    justify-content: flex-start;
    padding-left: 16px;
    border-bottom: 1px solid var(--line);
  }

  .category-grid a:nth-child(2n) {
    border-right: 0;
  }

  .category-grid a:nth-last-child(-n + 2) {
    border-bottom: 0;
  }

  .section {
    padding: 66px 0;
  }

  .section-head h2,
  .question-panel h2,
  .mission-panel h2 {
    font-size: 30px;
  }

  .section-head > .text-link {
    display: none;
  }

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

  .question-section {
    padding-bottom: 66px;
  }

  .question-panel,
  .mission-panel {
    display: block;
    padding: 38px 25px;
    text-align: center;
  }

  .question-panel .button {
    margin-top: 24px;
  }

  .page-hero {
    padding: 62px 0;
  }

  .page-hero h1,
  .about-hero h1,
  .article-header h1 {
    font-size: 38px;
    letter-spacing: -1.5px;
  }

  .filter-row {
    justify-content: flex-start;
  }

  .article-page {
    padding-top: 38px;
  }

  .back-link {
    margin-bottom: 30px;
  }

  .article-cover {
    min-height: 235px;
    border-radius: 20px;
  }

  .article-layout {
    margin-top: 38px;
  }

  .article-content h2 {
    font-size: 24px;
  }

  .article-content p {
    font-size: 16px;
  }

  .about-hero {
    padding: 55px 0 68px;
  }

  .about-art,
  .about-art img {
    min-height: 340px;
    height: 340px;
  }

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

  .mission-section {
    padding: 66px 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}