:root {
  --ink: #1f2933;
  --muted: #5f6b7a;
  --line: #d7dee8;
  --paper: #ffffff;
  --soft: #f4f7fb;
  --navy: #17365d;
  --blue: #235f9c;
  --red: #8f2e2e;
  --green: #2f6b57;
  --shadow: 0 18px 45px rgba(31, 41, 51, 0.12);
  font-family: "Noto Sans SC", "Microsoft YaHei", "Segoe UI", Arial, sans-serif;
  color: var(--ink);
  background: var(--paper);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-size: 16px;
  line-height: 1.7;
  background: var(--paper);
}

a {
  color: var(--blue);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

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

.skip-link {
  position: absolute;
  left: 12px;
  top: -48px;
  z-index: 20;
  padding: 8px 12px;
  background: var(--navy);
  color: #fff;
}

.skip-link:focus {
  top: 12px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid rgba(215, 222, 232, 0.9);
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(12px);
}

.header-inner {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 18px;
  width: min(1180px, calc(100% - 40px));
  min-height: 72px;
  margin: 0 auto;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
}

.brand:hover {
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: 8px;
  background: var(--navy);
  color: #fff;
  font-weight: 700;
}

.brand strong,
.brand small {
  display: block;
  line-height: 1.25;
}

.brand small {
  color: var(--muted);
  font-size: 0.8rem;
}

.site-nav {
  display: flex;
  justify-content: flex-end;
  gap: 18px;
}

.site-nav a {
  color: var(--ink);
  font-size: 0.94rem;
}

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

.language-button,
.menu-button,
.year-button,
.text-button,
.back-to-top,
.button {
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fff;
  color: var(--ink);
  font: inherit;
  cursor: pointer;
}

.language-button {
  min-width: 58px;
  padding: 7px 12px;
}

.menu-button {
  display: none;
  width: 42px;
  height: 38px;
  padding: 8px;
}

.menu-button span {
  display: block;
  height: 2px;
  margin: 5px 0;
  background: var(--ink);
}

.hero-section {
  border-bottom: 1px solid var(--line);
  background: #f7f9fc;
}

.hero-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(280px, 0.7fr);
  gap: 54px;
  align-items: center;
  width: min(1180px, calc(100% - 40px));
  min-height: 560px;
  margin: 0 auto;
  padding: 64px 0 42px;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--red);
  font-weight: 700;
  font-size: 0.82rem;
  text-transform: uppercase;
}

.hero-copy h1 {
  margin: 0;
  color: var(--navy);
  font-size: 3rem;
  line-height: 1.12;
}

.hero-title {
  max-width: 760px;
  margin: 16px 0 0;
  color: var(--ink);
  font-size: 1.24rem;
  font-weight: 700;
}

.hero-summary {
  max-width: 760px;
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 1.06rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.button {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 8px 16px;
  font-weight: 700;
}

.button:hover {
  text-decoration: none;
}

.button.primary {
  border-color: var(--navy);
  background: var(--navy);
  color: #fff;
}

.button.secondary {
  border-color: var(--blue);
  color: var(--blue);
}

.portrait-panel {
  margin: 0;
  justify-self: end;
  width: min(360px, 100%);
}

.portrait-panel img {
  display: block;
  aspect-ratio: 1 / 1;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  object-fit: cover;
  object-position: center center;
  background: #fff;
  box-shadow: var(--shadow);
}

.stat-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
  border-top: 1px solid var(--line);
}

.stat-item {
  padding: 24px 22px;
  border-right: 1px solid var(--line);
}

.stat-item:last-child {
  border-right: 0;
}

.stat-item strong,
.stat-item span {
  display: block;
}

.stat-item strong {
  color: var(--navy);
  font-size: 1.8rem;
  line-height: 1.15;
}

.stat-item span {
  margin-top: 6px;
  color: var(--muted);
}

.page-section,
.contact-inner {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
  padding: 78px 0;
}

.band {
  width: 100%;
  max-width: none;
  padding-inline: max(20px, calc((100% - 1180px) / 2));
  background: var(--soft);
}

.section-heading {
  max-width: 760px;
  margin-bottom: 30px;
}

.section-heading.wide {
  display: grid;
  grid-template-columns: minmax(260px, 0.8fr) minmax(300px, 1fr);
  gap: 34px;
  max-width: none;
  align-items: end;
}

.section-heading h2,
.contact-section h2 {
  margin: 0;
  color: var(--navy);
  font-size: 2rem;
  line-height: 1.25;
}

.section-heading p:not(.eyebrow) {
  margin: 0;
  color: var(--muted);
}

.about-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.72fr);
  gap: 42px;
}

.prose p {
  margin: 0 0 18px;
  color: #334155;
}

.timeline-panel {
  border-left: 4px solid var(--navy);
  padding-left: 24px;
}

.timeline-panel h3,
.two-column-list h3,
.contact-grid h3 {
  margin: 0 0 14px;
  color: var(--navy);
  font-size: 1rem;
}

.timeline-panel h3:not(:first-child) {
  margin-top: 30px;
}

.timeline {
  display: grid;
  gap: 16px;
}

.timeline-item {
  display: grid;
  grid-template-columns: 132px 1fr;
  gap: 14px;
}

.timeline-item time {
  color: var(--green);
  font-weight: 700;
  font-size: 0.9rem;
}

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

.research-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.research-card,
.two-column-list article,
.publication-item {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.research-card {
  padding: 24px;
}

.research-number {
  color: var(--red);
  font-weight: 800;
  font-size: 0.86rem;
}

.research-card h3 {
  margin: 8px 0 10px;
  color: var(--navy);
  font-size: 1.08rem;
  line-height: 1.35;
}

.publication-title {
  margin: 10px 0 8px !important;
  color: var(--ink) !important;
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.45;
}

.research-card p,
.publication-item p {
  margin: 0;
  color: var(--muted);
}

.publication-authors {
  margin-top: 12px !important;
  color: #334155 !important;
  font-size: 0.92rem;
  line-height: 1.55;
}

.publication-toolbar {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: center;
  margin-bottom: 20px;
}

.year-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.year-button,
.text-button {
  padding: 7px 12px;
}

.year-button.active {
  border-color: var(--navy);
  background: var(--navy);
  color: #fff;
}

.text-button {
  color: var(--blue);
  font-weight: 700;
}

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

.publication-item {
  padding: 20px;
}

.publication-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}

.publication-year,
.publication-journal {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  border-radius: 6px;
  padding: 2px 8px;
  font-size: 0.82rem;
  font-weight: 700;
}

.publication-year {
  background: #edf3fa;
  color: var(--navy);
}

.publication-journal {
  background: #f7eeee;
  color: var(--red);
  font-size: 1rem;
  font-weight: 800;
}

.two-column-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}

.two-column-list article {
  padding: 24px;
}

.two-column-list ul,
.service-list {
  display: grid;
  gap: 12px;
  margin: 0;
  padding-left: 20px;
  color: #334155;
}

.service-list {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 28px;
}

.contact-section {
  background: var(--navy);
  color: #fff;
}

.contact-section .eyebrow,
.contact-section h2,
.contact-grid h3 {
  color: #fff;
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
  margin-top: 28px;
}

.contact-grid p {
  margin: 0;
  color: #dbe6f2;
}

.contact-grid a {
  color: #fff;
}

.profile-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.profile-links a {
  border: 1px solid rgba(255, 255, 255, 0.35);
  border-radius: 6px;
  padding: 6px 10px;
}

.profile-links a:hover {
  background: rgba(255, 255, 255, 0.1);
  text-decoration: none;
}

.site-footer {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 72px;
  color: var(--muted);
}

.back-to-top {
  position: fixed;
  right: 18px;
  bottom: 18px;
  width: 42px;
  height: 42px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 160ms ease;
}

.back-to-top.visible {
  opacity: 1;
  pointer-events: auto;
}

@media (max-width: 900px) {
  .header-inner {
    grid-template-columns: auto auto auto;
  }

  .menu-button {
    display: inline-block;
    justify-self: end;
  }

  .site-nav {
    position: absolute;
    left: 20px;
    right: 20px;
    top: 72px;
    display: none;
    flex-direction: column;
    gap: 0;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: #fff;
    box-shadow: var(--shadow);
  }

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

  .site-nav a {
    padding: 12px 16px;
    border-bottom: 1px solid var(--line);
  }

  .site-nav a:last-child {
    border-bottom: 0;
  }

  .hero-inner,
  .about-grid,
  .section-heading.wide,
  .two-column-list,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .hero-inner {
    min-height: 0;
    padding-top: 44px;
  }

  .portrait-panel {
    justify-self: start;
    width: min(280px, 78vw);
  }

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

  .stat-item:nth-child(2) {
    border-right: 0;
  }

  .stat-item:nth-child(-n + 2) {
    border-bottom: 1px solid var(--line);
  }

  .research-grid,
  .service-list {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 560px) {
  .header-inner,
  .hero-inner,
  .stat-strip,
  .page-section,
  .contact-inner {
    width: min(100% - 28px, 1180px);
  }

  .brand small {
    display: none;
  }

  .hero-copy h1 {
    font-size: 2.25rem;
  }

  .hero-title {
    font-size: 1.06rem;
  }

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

  .stat-item {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .stat-item:last-child {
    border-bottom: 0;
  }

  .page-section,
  .contact-inner {
    padding: 56px 0;
  }

  .band {
    padding-inline: 14px;
  }

  .timeline-item {
    grid-template-columns: 1fr;
    gap: 2px;
  }

  .publication-toolbar {
    align-items: flex-start;
    flex-direction: column;
  }
}