:root {
  --color-bg: #ffffff;
  --color-bg-soft: #f4f8ff;
  --color-text: #172033;
  --color-muted: #58657d;
  --color-primary: #1167d8;
  --color-primary-dark: #0c4ca8;
  --color-border: #d9e5f5;
  --shadow-soft: 0 18px 45px rgba(17, 103, 216, 0.12);
  --shadow-card: 0 12px 28px rgba(23, 32, 51, 0.08);
  --radius: 8px;
  --container: 1120px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC",
    "Microsoft YaHei", Arial, sans-serif;
  --font-kai: "Kaiti SC", "STKaiti", "KaiTi", "KaiTi_GB2312", "楷体",
    "DFKai-SB", serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
}

body {
  margin: 0;
  min-width: 320px;
  overflow-x: hidden;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  line-height: 1.7;
}

html:lang(zh-CN) body {
  font-family: var(--font-kai);
}

body.nav-open {
  overflow: hidden;
}

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

a:focus-visible,
button:focus-visible {
  outline: 3px solid rgba(17, 103, 216, 0.35);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  left: 16px;
  top: 16px;
  z-index: 200;
  transform: translateY(-140%);
  border-radius: var(--radius);
  background: var(--color-primary);
  color: #ffffff;
  padding: 10px 14px;
  transition: transform 180ms ease;
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid rgba(217, 229, 245, 0.75);
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(16px);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  width: min(100% - 40px, var(--container));
  min-height: 72px;
  margin: 0 auto;
}

.brand {
  display: inline-flex;
  align-items: center;
  flex: 0 1 auto;
  gap: 10px;
  font-weight: 750;
  color: var(--color-text);
}

.nav-right,
.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav-menu a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  border-radius: var(--radius);
  color: var(--color-muted);
  font-size: 0.96rem;
  font-weight: 650;
  padding: 0 14px;
  transition:
    background 180ms ease,
    color 180ms ease;
}

.lang-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 48px;
  height: 40px;
  padding: 0 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: #ffffff;
  color: var(--color-primary-dark);
  cursor: pointer;
  font: inherit;
  font-weight: 850;
  line-height: 1;
  box-shadow: 0 8px 18px rgba(17, 103, 216, 0.08);
  transition:
    background 180ms ease,
    border-color 180ms ease,
    color 180ms ease,
    transform 180ms ease;
}

.lang-toggle:hover {
  transform: translateY(-1px);
  border-color: rgba(17, 103, 216, 0.35);
  background: var(--color-bg-soft);
  color: var(--color-primary);
}

.nav-menu a:hover,
.nav-menu a.is-active {
  background: var(--color-bg-soft);
  color: var(--color-primary-dark);
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  place-items: center;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: #ffffff;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  margin: 3px 0;
  border-radius: 999px;
  background: var(--color-text);
}

.section {
  width: min(100% - 40px, var(--container));
  margin: 0 auto;
  padding: 96px 0;
}

.hero {
  display: grid;
  min-height: calc(100svh - 72px);
  align-items: center;
  grid-template-columns: minmax(0, 1.08fr) minmax(280px, 0.92fr);
  gap: 56px;
  padding-top: 80px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--color-primary);
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

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

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.2;
  letter-spacing: 0;
}

h1 {
  max-width: 780px;
  font-size: 4.4rem;
}

h1 a {
  color: inherit;
}

h1 a:hover {
  color: var(--color-primary-dark);
  text-decoration: underline;
  text-underline-offset: 6px;
}

h2 {
  font-size: 2.8rem;
}

h3 {
  font-size: 1.22rem;
}

.hero-text {
  max-width: 680px;
  margin: 24px 0 18px;
  color: var(--color-muted);
  font-size: 1.22rem;
}

.hero-about {
  max-width: 740px;
  margin: 0 0 24px;
  color: var(--color-muted);
  font-size: 1.02rem;
}

.hero-about a {
  color: var(--color-primary-dark);
  font-weight: 800;
  overflow-wrap: anywhere;
}

.hero-about a:hover {
  text-decoration: underline;
  text-underline-offset: 4px;
}

.hero-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 0 0 30px;
}

.hero-links a {
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  color: var(--color-primary-dark);
  font-weight: 800;
  padding: 0 14px;
}

.hero-links a:hover {
  border-color: rgba(17, 103, 216, 0.35);
  background: var(--color-bg-soft);
}

.hero-visual {
  position: relative;
  aspect-ratio: 617 / 720;
  min-height: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: #ffffff;
  box-shadow: var(--shadow-soft);
  padding: 14px;
}

.portrait-frame {
  overflow: hidden;
  width: 100%;
  height: 100%;
  border-radius: var(--radius);
  background: #ffffff;
}

.portrait-frame img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
  object-position: center;
}

.section-inner {
  max-width: 880px;
}

.section-heading p {
  margin: 18px 0 0;
  color: var(--color-muted);
  font-size: 1.08rem;
}

.research {
  width: 100%;
  max-width: none;
  background: var(--color-bg-soft);
}

.research .section-inner {
  width: min(100% - 40px, var(--container));
  max-width: var(--container);
  margin: 0 auto;
}

.section-heading {
  max-width: 720px;
}

.publication-list {
  display: grid;
  gap: 16px;
  margin: 36px 0 0;
  padding: 0;
  list-style: none;
}

.publication-item {
  position: relative;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: #ffffff;
  padding: 24px 26px 24px 74px;
  box-shadow: var(--shadow-card);
}

.publication-item::before {
  position: absolute;
  left: 24px;
  top: 24px;
  color: var(--color-primary);
  content: counter(list-item, decimal-leading-zero);
  font-weight: 850;
}

.publication-item > a {
  color: var(--color-text);
  font-size: 1.08rem;
  font-weight: 850;
  line-height: 1.35;
}

.publication-item > a:hover {
  color: var(--color-primary-dark);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.publication-item p {
  margin: 8px 0 0;
  color: var(--color-muted);
  font-size: 0.98rem;
}

.publication-authors a {
  color: var(--color-primary-dark);
  font-size: inherit;
  font-weight: 750;
}

.publication-authors a:hover {
  text-decoration: underline;
  text-underline-offset: 4px;
}

.info-list {
  display: grid;
  gap: 18px;
  margin-top: 36px;
}

.info-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: #ffffff;
  padding: 26px;
  box-shadow: var(--shadow-card);
  transition:
    border-color 180ms ease,
    box-shadow 180ms ease,
    transform 180ms ease;
}

.info-item:hover {
  transform: translateY(-4px);
  border-color: rgba(17, 103, 216, 0.35);
  box-shadow: 0 18px 38px rgba(23, 32, 51, 0.12);
}

.info-item p {
  margin: 14px 0 24px;
  color: var(--color-muted);
}

.resource-list {
  display: grid;
  gap: 12px;
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
}

.resource-list li {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}

.resource-meta {
  display: inline-flex;
  align-items: center;
  min-height: 24px;
  border: 1px solid rgba(17, 103, 216, 0.24);
  border-radius: 999px;
  color: var(--color-primary-dark);
  font-size: 0.78rem;
  font-weight: 850;
  padding: 0 8px;
}

.info-item .seminar-sentence {
  margin-bottom: 12px;
}

.info-item .seminar-sentence:last-child {
  margin-bottom: 0;
}

.info-item a {
  color: var(--color-primary-dark);
  font-weight: 800;
  overflow-wrap: anywhere;
}

.info-item a:hover {
  text-decoration: underline;
  text-underline-offset: 4px;
}

.site-footer {
  border-top: 1px solid var(--color-border);
  background: #f9fbff;
  color: var(--color-muted);
  text-align: center;
  padding: 28px 20px;
}

.site-footer p {
  margin: 0;
}

.site-footer a {
  color: var(--color-primary-dark);
  font-weight: 800;
}

.site-footer a:hover {
  text-decoration: underline;
  text-underline-offset: 4px;
}

.reveal {
  transform: translateY(18px);
  opacity: 0;
  transition:
    opacity 650ms ease,
    transform 650ms ease;
}

.reveal.is-visible {
  transform: translateY(0);
  opacity: 1;
}

@media (max-width: 860px) {
  .nav {
    width: min(100% - 32px, var(--container));
  }

  .nav-right {
    margin-left: auto;
  }

  .nav-toggle {
    display: grid;
  }

  .nav-menu {
    position: fixed;
    left: 16px;
    right: 16px;
    top: 84px;
    display: grid;
    gap: 6px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    background: #ffffff;
    padding: 10px;
    box-shadow: var(--shadow-card);
    transform: translateY(-16px);
    opacity: 0;
    pointer-events: none;
    transition:
      opacity 180ms ease,
      transform 180ms ease;
  }

  .nav-menu.is-open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav-menu a {
    width: 100%;
    justify-content: center;
  }

  .section {
    width: min(100% - 32px, var(--container));
    padding: 72px 0;
  }

  .hero {
    grid-template-columns: 1fr;
    gap: 34px;
    min-height: auto;
    padding-top: 64px;
  }

  h1 {
    font-size: 3.2rem;
  }

  h2 {
    font-size: 2.3rem;
  }

  .publication-item {
    padding: 22px 22px 22px 64px;
  }
}

@media (max-width: 520px) {
  .brand {
    max-width: 178px;
  }

  .brand > span:last-child {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  h1 {
    font-size: 2.32rem;
  }

  h2 {
    font-size: 1.9rem;
  }

  .hero-text {
    font-size: 1.08rem;
  }

  .hero-visual {
    padding: 10px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }

  .reveal {
    transform: none;
    opacity: 1;
  }
}