:root {
  --blue: #0579bb;
  --blue-dark: #0063a0;
  --blue-soft: #eaf5ff;
  --line: #88bde6;
  --text: #243447;
  --muted: #5a6b7c;
  --bg: #edf6fc;
  --card: #ffffff;
  --shadow: 0 12px 30px rgba(0, 84, 140, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", "Noto Sans CJK SC", Arial, sans-serif;
  line-height: 1.75;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  min-height: 64px;
  padding: 0 36px;
  background: linear-gradient(90deg, var(--blue-dark), var(--blue));
  color: #fff;
  box-shadow: 0 3px 12px rgba(0, 0, 0, 0.14);
}

.brand {
  min-width: 335px;
  margin-right: 24px;
}

.brand h1 {
  margin: 0;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 25px;
  line-height: 1.1;
  letter-spacing: 0.2px;
}

.brand p {
  margin: 2px 0 0;
  font-size: 13px;
  opacity: 0.9;
}

.top-nav {
  display: flex;
  align-items: stretch;
  justify-content: flex-start;
  gap: 2px;
  width: 100%;
  min-width: 0;
}

.top-nav a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 13px;
  min-height: 64px;
  color: rgba(255, 255, 255, 0.86);
  text-decoration: none;
  white-space: nowrap;
  font-size: 15px;
  transition: background 0.2s ease, color 0.2s ease;
}

.top-nav a:hover,
.top-nav a.active {
  background: rgba(255, 255, 255, 0.15);
  color: #fff;
}

.top-nav a.english {
  margin-left: auto;
  font-weight: 600;
}

.menu-toggle {
  display: none;
  margin-left: auto;
  border: 1px solid rgba(255,255,255,0.45);
  border-radius: 4px;
  background: transparent;
  color: #fff;
  font-size: 22px;
  line-height: 1;
  padding: 8px 10px;
  cursor: pointer;
}

.page-shell {
  display: grid;
  grid-template-columns: 310px minmax(0, 1fr);
  gap: 18px;
  width: min(1120px, calc(100% - 48px));
  margin: 24px auto 0;
  align-items: start;
}

.profile-card {
  background: var(--card);
  padding: 24px 24px 22px;
  box-shadow: var(--shadow);
  border: 1px solid rgba(135, 187, 229, 0.35);
}

.portrait {
  display: block;
  width: 100%;
  aspect-ratio: 4 / 4.7;
  object-fit: cover;
  object-position: center;
  border: 1px solid #e0edf7;
  background: #f7fbff;
}

.profile-info {
  margin-top: 20px;
  font-size: 15px;
}

.profile-info p {
  margin: 0 0 8px;
}

.profile-info a {
  color: var(--blue-dark);
  text-decoration: none;
}

.profile-info a:hover {
  text-decoration: underline;
}

.contact-btn {
  display: inline-block;
  margin-top: 8px;
  padding: 8px 17px;
  border-radius: 4px;
  background: #2d83c5;
  color: #fff !important;
  text-decoration: none !important;
  font-weight: 600;
}

.contact-btn:hover {
  background: var(--blue-dark);
}

.content-panel {
  background: var(--card);
  padding: 24px 20px 34px;
  box-shadow: var(--shadow);
  border: 1px solid rgba(135, 187, 229, 0.25);
}

.content-section {
  scroll-margin-top: 86px;
  margin: 0 0 28px;
  padding: 0 8px;
}

.content-section:last-child {
  margin-bottom: 0;
}

.content-section h2 {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 14px;
  padding: 5px 20px 5px 15px;
  min-width: 240px;
  border: 1px solid var(--line);
  border-radius: 6px;
  color: #2c80c9;
  background: #fff;
  font-size: 27px;
  font-weight: 500;
  line-height: 1.25;
}

.section-icon {
  display: inline-flex;
  width: 28px;
  height: 28px;
  align-items: center;
  justify-content: center;
  border: 2px solid currentColor;
  border-radius: 3px;
  color: #2c80c9;
  font-size: 15px;
  line-height: 1;
}

.content-section p {
  margin: 0 0 12px;
  padding: 0 20px;
  text-align: justify;
}

.timeline,
.research-list {
  list-style: none;
  margin: 2px 0 0;
  padding: 0 20px;
}

.timeline li {
  display: grid;
  grid-template-columns: 150px minmax(0, 1fr);
  gap: 16px;
  margin: 9px 0;
}

.timeline time {
  font-weight: 700;
  color: #333;
  white-space: nowrap;
}

.research-list {
  list-style: decimal;
  padding-left: 44px;
}

.research-list li {
  margin: 8px 0;
}

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

.site-footer {
  margin: 30px auto 0;
  padding: 24px 18px 26px;
  text-align: center;
  color: #527086;
  font-size: 14px;
}

.site-footer p {
  margin: 0 0 6px;
}

.site-footer a {
  color: #527086;
  text-decoration: none;
}

.site-footer a:hover {
  color: var(--blue-dark);
  text-decoration: underline;
}

@media (max-width: 1180px) {
  .site-header {
    padding: 0 18px;
  }
  .brand {
    min-width: 280px;
  }
  .top-nav a {
    padding: 0 8px;
    font-size: 14px;
  }
}

@media (max-width: 980px) {
  .site-header {
    flex-wrap: wrap;
    padding: 10px 16px;
  }
  .brand {
    min-width: 0;
  }
  .brand h1 {
    font-size: 22px;
  }
  .menu-toggle {
    display: block;
  }
  .top-nav {
    display: none;
    width: 100%;
    margin-top: 10px;
    flex-wrap: wrap;
    background: rgba(0, 72, 116, 0.2);
    border-radius: 6px;
    overflow: hidden;
  }
  .top-nav.open {
    display: flex;
  }
  .top-nav a,
  .top-nav a.english {
    min-height: 42px;
    margin-left: 0;
    flex: 1 1 120px;
  }
  .page-shell {
    grid-template-columns: 1fr;
    width: min(760px, calc(100% - 28px));
  }
  .portrait {
    max-height: 420px;
  }
}

@media (max-width: 640px) {
  .page-shell {
    width: calc(100% - 20px);
    margin-top: 12px;
  }
  .profile-card,
  .content-panel {
    padding: 16px;
  }
  .content-section {
    padding: 0;
  }
  .content-section h2 {
    min-width: 0;
    width: 100%;
    font-size: 22px;
  }
  .content-section p,
  .timeline,
  .research-list {
    padding-left: 4px;
    padding-right: 4px;
  }
  .timeline li {
    grid-template-columns: 1fr;
    gap: 2px;
    padding-bottom: 8px;
    border-bottom: 1px dashed #d8e8f4;
  }
  .research-list {
    padding-left: 28px;
  }
}