:root {
  --bg: #f4f8ff;
  --surface: #ffffff;
  --surface-soft: #f0f6ff;
  --text: #10172c;
  --muted: #637085;
  --brand: #5f76f3;
  --brand-2: #4e67df;
  --accent: #6f8ef7;
  --line: #e4ebf5;
  --shadow: 0 18px 45px rgba(49, 64, 93, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(circle at 18% 0%, rgba(207, 218, 255, 0.55), transparent 32%),
    radial-gradient(circle at 92% 12%, rgba(218, 255, 232, 0.56), transparent 28%),
    var(--bg);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 16px;
  line-height: 1.65;
}

a {
  color: var(--brand-2);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(249, 252, 255, 0.9);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(10px);
}

.container {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 76px;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--text);
  font-weight: 700;
  letter-spacing: 0;
}

.brand img {
  width: 54px;
  height: auto;
  display: block;
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  color: var(--text);
  font-size: 24px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.site-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 0 14px;
  border-radius: 8px;
  color: var(--text);
  font-weight: 700;
}

.site-nav a[aria-current="page"],
.site-nav a:hover {
  background: #edf4fb;
  text-decoration: none;
}

.hero {
  padding: 72px 0 42px;
  background:
    radial-gradient(circle at 84% 18%, rgba(223, 255, 235, 0.72), transparent 32%),
    radial-gradient(circle at 16% 0%, rgba(220, 229, 255, 0.72), transparent 32%),
    linear-gradient(135deg, rgba(255, 255, 255, 0.96), rgba(248, 252, 255, 0.94));
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  color: var(--text);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 48px;
  align-items: center;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--accent);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  margin: 0 0 18px;
  line-height: 1.18;
}

h1 {
  max-width: 840px;
  font-size: 44px;
}

h2 {
  font-size: 30px;
}

h3 {
  font-size: 21px;
}

.hero p {
  max-width: 820px;
  color: var(--muted);
  font-size: 18px;
}

.hero-actions,
.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 18px;
  border: 1px solid transparent;
  border-radius: 8px;
  background: linear-gradient(135deg, #5d82f4, #6d63f1);
  color: #ffffff;
  font-weight: 700;
}

.button:hover {
  text-decoration: none;
  background: linear-gradient(135deg, #4c70e6, #5b55dc);
}

.button.secondary {
  background: #ffffff;
  color: var(--text);
  border-color: var(--line);
  box-shadow: 0 10px 24px rgba(49, 64, 93, 0.06);
}

.button.secondary:hover {
  background: var(--surface-soft);
}

.info-panel {
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid rgba(213, 223, 239, 0.92);
  border-radius: 8px;
  padding: 24px;
}

.info-panel dl {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 10px 16px;
  margin: 0;
}

.info-panel dt {
  color: var(--accent);
  font-weight: 700;
}

.info-panel dd {
  margin: 0;
}

.section {
  padding: 56px 0;
}

.section.alt {
  background: rgba(255, 255, 255, 0.64);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.content-narrow {
  max-width: 900px;
}

.grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

.card {
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 22px;
  box-shadow: var(--shadow);
}

.chair-card {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 264px;
  gap: 18px;
  align-items: start;
}

.chair-card .portrait {
  order: 2;
}

.profile-card {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 236px;
  gap: 18px;
  align-items: start;
}

.profile-card .portrait {
  grid-column: 2;
  grid-row: 1 / span 3;
}

.avatar {
  display: grid;
  place-items: center;
  width: 76px;
  height: 76px;
  border-radius: 8px;
  background: var(--surface-soft);
  color: var(--brand);
  font-size: 24px;
  font-weight: 700;
}

.portrait {
  max-width: 236px;
  max-height: 296px;
  width: auto;
  height: auto;
  border-radius: 8px;
  border: 1px solid var(--line);
  object-fit: contain;
  object-position: center;
  background: var(--surface-soft);
  justify-self: end;
}

.chair-card .portrait {
  max-width: 264px;
  max-height: 336px;
  width: auto;
  height: auto;
}

.portrait-jiatong {
  width: 216px;
  height: 266px;
  max-width: none;
  max-height: none;
  object-fit: cover;
}

.chair-card p {
  margin-bottom: 0;
}

.meta {
  margin: 0 0 10px;
  color: var(--muted);
  font-weight: 700;
}

.topic-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px 22px;
  padding-left: 20px;
}

.dates-list {
  display: grid;
  gap: 10px;
  padding: 0;
  list-style: none;
}

.dates-list li {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 14px 16px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.placeholder {
  padding: 28px;
  border: 1px dashed var(--line);
  border-radius: 8px;
  background: var(--surface);
  color: var(--muted);
}

.site-footer {
  padding: 38px 0;
  color: #dce6ff;
  background: #10172c;
}

.site-footer a {
  color: #9fb0ff;
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 30px;
}

.small {
  color: var(--muted);
  font-size: 14px;
}

@media (max-width: 840px) {
  .header-inner {
    min-height: 68px;
  }

  .nav-toggle {
    display: inline-grid;
    place-items: center;
  }

  .site-nav {
    position: absolute;
    top: 68px;
    right: 20px;
    left: 20px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 12px;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 8px;
    box-shadow: var(--shadow);
  }

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

  .hero {
    padding: 46px 0 32px;
  }

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

  h1 {
    font-size: 34px;
  }

  .dates-list li {
    display: block;
  }
}

@media (max-width: 560px) {
  .chair-card,
  .profile-card {
    grid-template-columns: 1fr;
  }

  .profile-card .portrait {
    grid-column: auto;
    grid-row: auto;
    order: -1;
    max-width: 236px;
    max-height: 296px;
    width: auto;
    height: auto;
    justify-self: start;
  }

  .chair-card .portrait {
    grid-column: auto;
    grid-row: auto;
    order: -1;
    max-width: 264px;
    max-height: 336px;
    width: auto;
    height: auto;
    justify-self: start;
  }

  .profile-card .portrait-jiatong {
    width: 216px;
    height: 266px;
    max-width: none;
    max-height: none;
  }
}