/* ── Reset & base ─────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --blue:       #1a3a6b;
  --blue-mid:   #2553a0;
  --blue-light: #3b7dd8;
  --accent:     #e8a020;
  --bg:         #ffffff;
  --bg-alt:     #f6f8fc;
  --text:       #1a1f2e;
  --text-muted: #5a6175;
  --border:     #e2e8f0;
  --radius:     12px;
  --shadow-sm:  0 2px 8px rgba(26,58,107,.08);
  --shadow-md:  0 6px 24px rgba(26,58,107,.12);
  --nav-h:      68px;
  --transition: 0.22s ease;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', sans-serif;
  font-size: 16px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
}

a { color: var(--blue-light); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--blue); }

img { max-width: 100%; display: block; }

/* ── Layout helpers ───────────────────────────────────────────── */
.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

.section        { padding: 96px 0; }
.section-alt    { background: var(--bg-alt); }

.section-header {
  text-align: center;
  max-width: 620px;
  margin: 0 auto 64px;
}

.section-label {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--blue-light);
  margin-bottom: 8px;
}

.section-title {
  font-family: 'Playfair Display', serif;
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 700;
  color: var(--blue);
  margin-bottom: 16px;
  line-height: 1.2;
}

.section-desc {
  color: var(--text-muted);
  font-size: 17px;
}

/* ── Navigation ───────────────────────────────────────────────── */
#navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 999;
  height: var(--nav-h);
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: box-shadow var(--transition);
}

#navbar.scrolled { box-shadow: var(--shadow-md); }

.nav-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.nav-logo {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
  color: var(--blue);
}

.logo-main {
  font-weight: 700;
  font-size: 17px;
  letter-spacing: -.01em;
}

.logo-sub {
  font-size: 11px;
  color: var(--text-muted);
  font-weight: 400;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 8px;
}

.nav-links a {
  padding: 6px 14px;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-muted);
  transition: background var(--transition), color var(--transition);
}

.nav-links a:hover {
  background: var(--bg-alt);
  color: var(--blue);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--blue);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

/* ── Hero ─────────────────────────────────────────────────────── */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  overflow: hidden;
  padding-top: var(--nav-h);
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, #0a1f4a 0%, #1a3a6b 45%, #2553a0 100%);
  z-index: 0;
}

.hero-bg::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 20% 50%, rgba(59,125,216,.25) 0%, transparent 60%),
    radial-gradient(circle at 80% 20%, rgba(232,160,32,.12) 0%, transparent 50%),
    url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Ccircle cx='30' cy='30' r='1'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 780px;
  padding: 0 24px;
}

.hero-label {
  font-size: 13px;
  font-weight: 500;
  letter-spacing: .15em;
  text-transform: uppercase;
  color: rgba(255,255,255,.6);
  margin-bottom: 16px;
}

.hero-title {
  font-family: 'Playfair Display', serif;
  font-size: clamp(48px, 8vw, 88px);
  font-weight: 700;
  color: #fff;
  line-height: 1.05;
  margin-bottom: 24px;
}

.hero-subtitle {
  font-size: clamp(17px, 2.5vw, 21px);
  color: rgba(255,255,255,.78);
  line-height: 1.55;
  margin-bottom: 40px;
}

.hero-cta {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 28px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
  border: 2px solid transparent;
}

.btn:hover { transform: translateY(-2px); }

.btn-primary {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
  box-shadow: 0 4px 18px rgba(232,160,32,.35);
}

.btn-primary:hover {
  background: #d4911a;
  border-color: #d4911a;
  color: #fff;
  box-shadow: 0 6px 24px rgba(232,160,32,.45);
}

.btn-outline {
  background: transparent;
  color: #fff;
  border-color: rgba(255,255,255,.5);
}

.btn-outline:hover {
  background: rgba(255,255,255,.1);
  border-color: rgba(255,255,255,.8);
  color: #fff;
}

.hero-scroll {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  z-index: 1;
  color: rgba(255,255,255,.5);
  font-size: 11px;
  letter-spacing: .1em;
  text-transform: uppercase;
}

.scroll-line {
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, rgba(255,255,255,.5), transparent);
  animation: scrollPulse 2s ease-in-out infinite;
}

@keyframes scrollPulse {
  0%, 100% { opacity: .5; transform: scaleY(1); }
  50%       { opacity: 1;  transform: scaleY(1.15); }
}

/* ── About ────────────────────────────────────────────────────── */
.about-grid {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 72px;
  align-items: start;
}

.about-photo-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
  position: sticky;
  top: calc(var(--nav-h) + 24px);
}

.about-photo-placeholder {
  width: 220px;
  height: 220px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--blue) 0%, var(--blue-light) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 56px;
  font-weight: 700;
  color: rgba(255,255,255,.9);
  font-family: 'Playfair Display', serif;
  box-shadow: var(--shadow-md);
}

.about-affiliations {
  display: flex;
  flex-direction: column;
  gap: 10px;
  width: 100%;
}

.affil-badge {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 16px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
}

.affil-badge img {
  width: 28px;
  height: 28px;
  object-fit: contain;
  flex-shrink: 0;
}

.about-text .section-label { text-align: left; }
.about-text .section-title  { text-align: left; margin-bottom: 20px; }

.about-bio {
  color: var(--text-muted);
  margin-bottom: 16px;
  font-size: 16.5px;
}

.about-bio:last-of-type { margin-bottom: 28px; }

.about-bio strong { color: var(--text); font-weight: 600; }

.about-links {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.icon-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text);
  transition: background var(--transition), border-color var(--transition), transform var(--transition);
}

.icon-link svg { width: 16px; height: 16px; color: var(--blue-light); }

.icon-link:hover {
  background: var(--blue);
  border-color: var(--blue);
  color: #fff;
  transform: translateY(-2px);
}

.icon-link:hover svg { color: #fff; }

/* ── Research ─────────────────────────────────────────────────── */
.research-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.research-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px 30px;
  transition: transform var(--transition), box-shadow var(--transition);
  position: relative;
  overflow: hidden;
}

.research-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 4px;
  background: var(--border);
  transition: background var(--transition);
}

.research-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.research-card--featured::before { background: var(--blue-light); }
.research-card--featured:hover::before { background: var(--blue); }

.research-card:not(.research-card--featured):hover::before { background: var(--accent); }

.research-icon {
  width: 56px;
  height: 56px;
  margin-bottom: 20px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.research-icon svg { width: 32px; height: 32px; }

.ai-icon { background: rgba(37,83,160,.1); color: var(--blue-mid); }
.ds-icon { background: rgba(59,125,216,.1); color: var(--blue-light); }
.hc-icon { background: rgba(220,38,38,.08); color: #c53030; }

.research-card h3 {
  font-size: 19px;
  font-weight: 700;
  color: var(--blue);
  margin-bottom: 12px;
}

.research-card p {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 20px;
}

.research-topics {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.research-topics li {
  font-size: 12px;
  font-weight: 500;
  padding: 4px 10px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 20px;
  color: var(--text-muted);
}

/* ── Team ─────────────────────────────────────────────────────── */
.team-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.team-card {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 24px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: box-shadow var(--transition), transform var(--transition);
}

.team-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-3px);
}

.pi-card {
  border-color: var(--blue-light);
  background: linear-gradient(135deg, rgba(26,58,107,.04) 0%, rgba(59,125,216,.04) 100%);
}

.placeholder-card { opacity: .65; }

.team-avatar {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--blue), var(--blue-light));
  color: #fff;
  font-weight: 700;
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.add-avatar {
  background: var(--bg-alt);
  color: var(--text-muted);
  border: 2px dashed var(--border);
  font-size: 24px;
  font-weight: 300;
}

.team-info h4 {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 2px;
}

.team-role {
  font-size: 13px;
  color: var(--blue-light);
  font-weight: 500;
  margin-bottom: 2px;
}

.team-affil {
  font-size: 12px;
  color: var(--text-muted);
}

/* ── Publications ─────────────────────────────────────────────── */
.pub-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg);
}

.pub-item {
  display: flex;
  align-items: flex-start;
  gap: 20px;
  padding: 24px 28px;
  border-bottom: 1px solid var(--border);
  transition: background var(--transition);
}

.pub-item:last-child { border-bottom: none; }
.pub-item:hover { background: rgba(37,83,160,.03); }

.pub-year {
  font-size: 13px;
  font-weight: 600;
  color: var(--blue-light);
  white-space: nowrap;
  padding-top: 2px;
  min-width: 40px;
}

.pub-body { flex: 1; }

.pub-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 4px;
}

.pub-authors {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 2px;
}

.pub-venue {
  font-size: 13px;
  color: var(--blue-light);
  font-style: italic;
}

.pub-link {
  align-self: center;
  font-size: 12px;
  font-weight: 600;
  padding: 5px 12px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text-muted);
  white-space: nowrap;
  flex-shrink: 0;
  transition: background var(--transition), color var(--transition);
}

.pub-link:hover {
  background: var(--blue);
  border-color: var(--blue);
  color: #fff;
}

.pub-cta {
  margin-top: 40px;
  text-align: center;
}

/* ── Contact ──────────────────────────────────────────────────── */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.contact-card {
  padding: 36px 28px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-align: center;
  transition: transform var(--transition), box-shadow var(--transition);
}

.contact-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.contact-icon {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--blue), var(--blue-light));
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
}

.contact-icon svg {
  width: 22px;
  height: 22px;
  color: #fff;
}

.contact-card h4 {
  font-size: 16px;
  font-weight: 700;
  color: var(--blue);
  margin-bottom: 8px;
}

.contact-card p {
  font-size: 14.5px;
  color: var(--text-muted);
  line-height: 1.6;
}

.contact-card a {
  color: var(--blue-light);
  font-weight: 500;
}

.contact-card a:hover { color: var(--blue); }

/* ── Footer ───────────────────────────────────────────────────── */
.footer {
  background: var(--blue);
  color: rgba(255,255,255,.8);
  padding: 40px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-title {
  font-weight: 700;
  font-size: 16px;
  color: #fff;
  margin-bottom: 2px;
}

.footer-sub {
  font-size: 13px;
  color: rgba(255,255,255,.55);
}

.footer-right {
  font-size: 13px;
  color: rgba(255,255,255,.5);
}

/* ── Responsive ───────────────────────────────────────────────── */
@media (max-width: 900px) {
  .about-grid     { grid-template-columns: 1fr; gap: 48px; }
  .about-photo-wrap { position: static; flex-direction: row; align-items: flex-start; }
  .research-grid  { grid-template-columns: 1fr; }
  .team-grid      { grid-template-columns: 1fr; }
  .contact-grid   { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .nav-links { display: none; flex-direction: column; position: absolute; top: var(--nav-h); left: 0; right: 0; background: #fff; border-bottom: 1px solid var(--border); padding: 16px 24px; gap: 4px; }
  .nav-links.open { display: flex; }
  .nav-toggle { display: flex; }
  .about-photo-wrap { flex-direction: column; align-items: center; }
  .section { padding: 64px 0; }
  .hero-cta { flex-direction: column; align-items: center; }
  .pub-item { flex-wrap: wrap; }
  .footer-inner { flex-direction: column; text-align: center; }
}