/* ===== Reset & Base ===== */
html, body {
  margin: 0;
  padding: 0;
  font-family: 'Lexend', sans-serif;
  scroll-behavior: smooth;
  color: #333;
  background: #fff;
}

a {
  color: #666;
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

/* ===== Header ===== */
.header-c {
  position: sticky;
  top: 0;
  z-index: 9999;
  background: #f5f0eb;
  border-bottom: 1px solid #e0dbd5;
}
.header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px 25px;
}
.header-l a {
  color: #222;
  font-family: Georgia, serif;
  font-size: 28px;
  letter-spacing: 1px;
}
.header-nav {
  display: flex;
  gap: 40px;
}
.header-nav a {
  color: #333;
  font-size: 17px;
  letter-spacing: 0.5px;
}
.header-nav a:hover {
  color: #000;
  text-decoration: none;
}

/* ===== Hero Section ===== */
.hero {
  position: relative;
  min-height: calc(100vh - 72px);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.hero-video {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 0;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.40);
  z-index: 1;
}
.hero-content {
  position: absolute;
  bottom: 60px;
  right: 60px;
  z-index: 2;
  text-align: right;
  padding: 0;
  max-width: 520px;
}
.hero-content p {
  color: rgba(255, 255, 255, 0.92);
  font-family: Georgia, serif;
  font-size: 32px;
  font-weight: 400;
  line-height: 1.4;
  margin: 0;
}

/* ===== Content Pages ===== */
.content-page {
  max-width: 900px;
  margin: 0 auto;
  padding: 60px 25px 80px;
}
.content-page h1 {
  font-size: 32px;
  color: #222;
  margin: 0 0 40px 0;
  font-weight: 400;
}

/* ===== Member Cards ===== */
.pi-section {
  margin-bottom: 60px;
}
.pi-card {
  display: flex;
  gap: 30px;
  align-items: flex-start;
}
.pi-card img {
  width: 180px;
  height: 180px;
  object-fit: cover;
  border-radius: 4px;
}
.pi-info h2 {
  margin: 0 0 10px 0;
  font-size: 24px;
  color: #222;
}
.pi-info .role {
  color: #666;
  font-size: 15px;
  margin-bottom: 16px;
}
.pi-info .contact-item {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
  font-size: 14px;
  color: #555;
}
.pi-info .social-links {
  display: flex;
  gap: 12px;
  margin-top: 16px;
}
.pi-info .social-links a {
  display: inline-block;
  padding: 6px 16px;
  border: 1px solid #ccc;
  border-radius: 4px;
  font-size: 13px;
  color: #555;
}
.pi-info .social-links a:hover {
  background: #f5f0eb;
  text-decoration: none;
}

.member-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 30px;
}
.member-card {
  text-align: center;
}
.member-card img {
  width: 140px;
  height: 140px;
  object-fit: cover;
  border-radius: 4px;
}
.member-card h3 {
  margin: 10px 0 4px 0;
  font-size: 16px;
  color: #222;
}
.member-card .name-zh {
  font-size: 16px;
  color: #555;
  margin-bottom: 4px;
}
.member-card .member-role {
  font-size: 13px;
  color: #666;
}
.member-card .member-bio {
  font-size: 12px;
  color: #999;
  margin-top: 4px;
}

/* PI bio sections */
.pi-bio-section {
  margin-top: 24px;
}
.pi-bio-section h3 {
  font-size: 13px;
  color: #888;
  letter-spacing: 0.5px;
  margin: 0 0 6px 0;
  font-weight: 500;
}
.pi-bio-section p {
  font-size: 13px;
  color: #555;
  line-height: 1.8;
  margin: 0;
}

/* ===== Alumni List ===== */
.alumni-list {
  list-style: none;
  padding: 0;
}
.alumni-list li {
  padding: 10px 0;
  border-bottom: 1px solid #f0f0f0;
  font-size: 15px;
}
.alumni-list li:last-child {
  border-bottom: none;
}
.alumni-list .alumni-name {
  color: #222;
  font-weight: 500;
}
.alumni-list .alumni-role {
  color: #888;
  font-size: 14px;
}
.alumni-list .name-zh {
  font-size: 16px;
  color: #555;
}

/* ===== Publications ===== */
.pub-list {
  list-style: none;
  padding: 0;
}
.pub-item {
  margin-bottom: 40px;
  padding-bottom: 40px;
  border-bottom: 1px solid #eee;
}
.pub-item:last-child {
  border-bottom: none;
}
.pub-number {
  font-size: 22px;
  color: #222;
  font-weight: 600;
  margin-bottom: 8px;
}
.pub-title {
  font-size: 20px;
  margin-bottom: 6px;
}
.pub-title a {
  color: #222;
}
.pub-authors {
  font-size: 15px;
  color: #555;
  margin-bottom: 4px;
}
.pub-citation {
  font-size: 15px;
  color: #555;
  font-style: italic;
}
.pub-highlight {
  display: inline-block;
  margin-top: 8px;
  padding: 3px 10px;
  background: #fef3e2;
  color: #b45309;
  font-size: 13px;
  border-radius: 3px;
}
.pub-toc {
  margin-top: 16px;
  text-align: center;
}
.pub-toc img {
  width: 500px;
  height: 280px;
  object-fit: contain;
}

/* ===== Responsive fallback (desktop-first) ===== */
@media (max-width: 768px) {
  .pi-card {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  .member-grid {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 20px;
  }
}

/* ===== Utility ===== */
.gotop {
  display: none;
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 40px;
  height: 40px;
  background: rgba(0,0,0,0.5);
  color: #fff;
  text-align: center;
  line-height: 40px;
  border-radius: 4px;
  cursor: pointer;
  z-index: 999;
  font-size: 18px;
}