:root {
  --nus-blue: #003D7C;
  --surface: #f7f9fc;
  --text: #1f2328;
  --muted: #5c6570;
  --border: #d9dde3;
  --max-width: 1120px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  color: var(--text);
  background: #fff;
  line-height: 1.6;
}
img { max-width: 100%; display: block; }

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

.container {
  width: min(var(--max-width), calc(100% - 2rem));
  margin: 0 auto;
}

.site-header {
  background: #ffffff;
  color: #fff;
  padding: 1rem 0 0.5rem;
  box-shadow: 0 1px 0 rgba(0,0,0,0.08);
  position: sticky;
  top: 0;
  z-index: 50;
}
.header-inner {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}
.logo-row {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.8rem 0.6rem 0.6rem;
}
.logo-link { display: inline-flex; align-items: center; }
.logo-row img {
  display: block;
  height: 48px;
  width: auto;
  object-fit: contain;
}
.logo-row .sublogo img { height: 48px; }

.navbar-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  background: #003D7C;  /* NUS Blue */
  padding: 0.5rem 0.6rem;
}

.nav-toggle {
  display: none;
  border: 1px solid rgba(255,255,255,0.35);
  background: rgba(255,255,255,0.08);
  color: #fff;
  border-radius: 10px;
  padding: 0.55rem 0.75rem;
  font-size: 1rem;
  cursor: pointer;
}
.site-nav ul {
  list-style: none;
  display: flex;
  gap: 0.25rem;
  padding: 0;
  margin: 0;
  flex-wrap: wrap;
  justify-content: flex-end;
}
.site-nav a {
  display: inline-block;
  padding: 0.55rem 0.8rem;
  border-radius: 999px;
  color: #fff;
  font-size: 0.95rem;
}
.site-nav a:hover {
  background: rgba(255,255,255,0.12);
  text-decoration: none;
}
.site-nav a.active {
  background: #fff;
  color: var(--nus-blue);
}

main { padding: 2rem 0 3rem; }

.page-title {
  margin: 0 0 1rem;
  font-size: clamp(1.7rem, 3vw, 2.4rem);
  line-height: 1.15;
}
.lead {
  color: var(--muted);
  max-width: 72ch;
}

.hero {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 2rem;
  align-items: start;
}
.hero > .page-title {
  grid-column: 1 / -1;   /* 关键：跨两列 */
  margin-bottom: 0.5rem;
}
.hero-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 1.25rem;
  box-shadow: 0 1px 2px rgba(16, 24, 40, 0.04);
}
.photo-wrap {
  overflow: hidden;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: var(--surface);
  justify-content: flex-end;
}
.photo-wrap img {
  width: 100%;
  max-width: 360px;
  height: auto;
  border-radius: 12px;
  border: 1px solid #ddd;
}
.project-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.2rem;
}
.pub-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.small-card {
  text-align: center;
  padding: 1rem;
}
.books-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}
.book-card {
  border: 1px solid #ddd;
  border-radius: 12px;
  padding: 0.9rem 1rem;
  background: #fff;
}
.book-title {
  margin: 0 0 0.4rem 0;
  font-size: 0.98rem;
  font-style: italic;
}
.book-meta {
  margin: 0;
  font-size: 0.9rem;
  color: #555;
}
.caption {
  margin-top: 0.75rem;
  color: var(--muted);
  font-size: 0.92rem;
}

.section { margin-top: 2rem; }
.section h2 {
  margin: 0 0 0.75rem;
  font-size: 1.35rem;
}
.section h3 {
  margin: 1.2rem 0 0.55rem;
  font-size: 1.08rem;
}
.section p { margin: 0.5rem 0; }
.list-clean {
  margin: 0.5rem 0 0;
  padding-left: 1.2rem;
}
.list-clean li { margin: 0.35rem 0; }

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.card {
  border: 1px solid var(--border);
  border-radius: 16px;
  background: #fff;
  padding: 1rem 1.1rem;
}
.card h3 { margin-top: 0; }

.person-card {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.person-photo {
  width: 100%;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: var(--surface);
}
.person-name {
  margin: 0;
  font-size: 1.05rem;
}
.person-role {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}
.person-meta {
  margin: 0;
  font-size: 0.95rem;
}

.meta {
  color: var(--muted);
  font-size: 0.95rem;
}
.kicker {
  display: inline-block;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #2fb4ff;
  font-weight: 700;
  margin-bottom: 0.35rem;
}
.section-gap {
  padding-top: 2rem;
}
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--surface);
  padding: 1.5rem 0;
  color: var(--muted);
  font-size: 0.95rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 1rem;
  align-items: start;
}

.small-note {
  font-size: 0.9rem;
  color: var(--muted);
}

.team-staff-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.2rem;
}
.team-student-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.2rem;
}
.clean-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 0.5rem;
  font-size: 0.95rem;
}
.clean-table th {
  text-align: left;
  font-weight: 600;
  padding: 0.5rem 0.3rem;
  border-bottom: 2px solid #ddd;
}
.clean-table td {
  padding: 0.45rem 0.3rem;
  vertical-align: top;
}
.clean-table tbody tr {
  border-bottom: 1px solid #f0f0f0;
}

@media (max-width: 900px) {
  .hero, .grid-2, .footer-grid { grid-template-columns: 1fr; }
  .nav-toggle { display: inline-flex; align-items: center; gap: 0.4rem; }
  .site-nav { display: none; width: 100%; }
  .site-nav.open { display: block; }
  .navbar-row { flex-wrap: wrap; }
  .site-nav ul {
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 0.25rem;
    width: 100%;
    padding-bottom: 0.75rem;
  }
  .site-nav a { border-radius: 12px; width: 100%; }
}