:root{
  --bg:#0b0f19;
  --card:#0f1629;
  --text:#e7ecff;
  --muted:#a8b3d6;
  --border:rgba(255,255,255,.10);
  --accent:#7aa2ff;
  --accent2:#66ffd3;
  --shadow: 0 12px 40px rgba(0,0,0,.35);
  --radius: 18px;
}

:root.light{
  --bg:#f7f8fc;
  --card:#ffffff;
  --text:#141a2a;
  --muted:#4e5a78;
  --border:rgba(20,26,42,.12);
  --accent:#2b62ff;
  --accent2:#00a58b;
  --shadow: 0 10px 30px rgba(20,26,42,.10);
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  font-family: ui-sans-serif, system-ui, -apple-system, "Hiragino Sans", "Noto Sans JP", "Segoe UI", sans-serif;
  background: radial-gradient(900px 500px at 15% 5%, rgba(122,162,255,.28), transparent 60%),
              radial-gradient(900px 500px at 85% 15%, rgba(102,255,211,.18), transparent 60%),
              var(--bg);
  color:var(--text);
  line-height:1.55;
}

a{color:inherit}
.container{max-width:1120px;margin:0 auto;padding:0 18px}

.site-header{
  position:sticky;top:0;z-index:50;
  backdrop-filter:saturate(140%) blur(14px);
  background: rgba(10,14,24,.70);
  border-bottom:1px solid var(--border);
}
:root.light .site-header{background: rgba(247,248,252,.75)}
.header-row{display:flex;align-items:center;gap:16px;padding:14px 0}

.brand{display:flex;align-items:center;gap:12px;text-decoration:none}
.brand-mark{
  width:36px;height:36px;border-radius:12px;
  display:grid;place-items:center;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color:#0b0f19;font-weight:900;
}
.brand-title{font-weight:800}
.brand-sub{display:block;color:var(--muted);font-size:12px;margin-top:2px}

.nav{display:flex;gap:14px;margin-left:auto}
.nav a{
  text-decoration:none;
  color:var(--muted);
  font-size:14px;
  padding:8px 10px;
  border-radius:999px;
}
.nav a:hover{color:var(--text);background:rgba(255,255,255,.06)}
:root.light .nav a:hover{background:rgba(20,26,42,.06)}

.header-actions{display:flex;gap:10px}

.btn{
  display:inline-flex;align-items:center;justify-content:center;
  gap:8px;
  padding:10px 12px;border-radius:999px;
  border:1px solid var(--border);
  background: rgba(255,255,255,.06);
  color:var(--text);
  text-decoration:none;
  cursor:pointer;
}
:root.light .btn{background: rgba(20,26,42,.04)}
.btn:hover{transform:translateY(-1px)}
.btn.primary{
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color:#0b0f19;border:none;font-weight:800;
}
.btn.ghost{width:42px}

.hero{display:grid;grid-template-columns:1.5fr .9fr;gap:18px;padding:34px 0 10px}
.hero h1{margin:0;font-size:44px;line-height:1.12;letter-spacing:-.02em}
.lead{color:var(--muted);font-size:16px;margin:14px 0 18px}

.hero-cta{display:flex;gap:10px;align-items:center;flex-wrap:wrap}
.muted{color:var(--muted);font-size:13px}
.kbd{
  border:1px solid var(--border);
  padding:2px 6px;border-radius:6px;font-size:12px;
  background:rgba(255,255,255,.05)
}
:root.light .kbd{background:rgba(20,26,42,.04)}

.hero-metrics{display:flex;gap:12px;flex-wrap:wrap;margin:18px 0}
.metric{
  border:1px solid var(--border);
  background:rgba(255,255,255,.04);
  border-radius:14px;
  padding:10px 12px;
  min-width:120px;
}
:root.light .metric{background:rgba(20,26,42,.03)}
.metric-num{font-weight:900;font-size:22px}
.metric-label{color:var(--muted);font-size:12px;margin-top:2px}

.section{padding:34px 0}
.section-head{display:flex;align-items:flex-end;justify-content:space-between;gap:12px;margin-bottom:12px}
.section-head h2{margin:0;font-size:22px}
.section-actions{display:flex;gap:10px;align-items:center}

.card{
  background: linear-gradient(180deg, rgba(255,255,255,.06), rgba(255,255,255,.03));
  border:1px solid var(--border);
  border-radius:var(--radius);
  padding:16px;
  box-shadow: var(--shadow);
}
:root.light .card{background:var(--card)}
.card.glass{background: rgba(255,255,255,.05)}
:root.light .card.glass{background: rgba(20,26,42,.03)}

.grid-2{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.grid-3{display:grid;grid-template-columns:1fr 1fr 1fr;gap:14px}

.bullets{margin:10px 0 0;padding-left:18px;color:var(--muted)}
.chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}
.chip{
  padding:6px 10px;border-radius:999px;
  border:1px solid var(--border);
  background:rgba(255,255,255,.04);
  font-size:12px;color:var(--muted)
}
:root.light .chip{background:rgba(20,26,42,.03)}

.input,.select{
  border:1px solid var(--border);
  background:rgba(255,255,255,.04);
  color:var(--text);
  border-radius:12px;
  padding:10px 12px;
  outline:none;
}
:root.light .input,:root.light .select{background:rgba(20,26,42,.03)}
.input{min-width:260px}
.select{min-width:140px}

.publist{margin:10px 0 0;padding-left:18px}
.publist li{padding:8px 0}
.publist a{color:var(--accent);text-decoration:none}
.publist a:hover{text-decoration:underline}

.list-head{display:flex;justify-content:space-between;align-items:center;gap:10px}
.link{color:var(--accent);text-decoration:none}
.link:hover{text-decoration:underline}

.timeline{margin:8px 0 0;padding-left:18px;color:var(--muted)}
.timeline li{padding:6px 0}

.contact-grid{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:14px;
}
.label{color:var(--muted);font-size:12px;margin-bottom:6px}

.site-footer{padding:22px 0 18px}

/* Professor Profile Card */
.professor-card{
  display:flex;
  gap:24px;
  align-items:flex-start;
  background: linear-gradient(180deg, rgba(255,255,255,.06), rgba(255,255,255,.03));
  border:1px solid var(--border);
  border-radius:var(--radius);
  padding:24px;
  margin-bottom:18px;
  box-shadow: var(--shadow);
}
:root.light .professor-card{background:var(--card)}

.professor-image{
  width:120px;
  height:120px;
  border-radius:50%;
  flex-shrink:0;
  border:3px solid var(--border);
  object-fit:cover;
}

.professor-info{flex:1}
.professor-info h3{margin:0 0 8px 0;font-size:22px}
.professor-info .title{
  color:var(--muted);
  font-size:14px;
  font-weight:400;
  margin-left:8px;
}
.professor-info .bio{
  color:var(--muted);
  margin:8px 0 12px;
  line-height:1.6;
}

.research-interests{
  list-style:none;
  padding:0;
  margin:12px 0;
  display:flex;
  flex-wrap:wrap;
  gap:8px;
}
.research-interests li{
  padding:6px 12px;
  background:rgba(122,162,255,.15);
  border:1px solid rgba(122,162,255,.3);
  border-radius:999px;
  font-size:13px;
  color:var(--accent);
}
:root.light .research-interests li{
  background:rgba(43,98,255,.08);
  border-color:rgba(43,98,255,.2);
}

.professor-links{
  display:flex;
  gap:12px;
  margin-top:14px;
  flex-wrap:wrap;
}
.professor-links a{
  padding:8px 14px;
  border:1px solid var(--border);
  border-radius:999px;
  text-decoration:none;
  font-size:13px;
  color:var(--accent);
  background:rgba(255,255,255,.04);
  transition:all .2s;
}
:root.light .professor-links a{background:rgba(20,26,42,.03)}
.professor-links a:hover{
  background:rgba(122,162,255,.15);
  transform:translateY(-1px);
}

/* Hero Simple (for Join Us page) */
.hero-simple{
  padding:34px 0 22px;
  text-align:center;
}
.hero-simple h1{
  margin:0;
  font-size:48px;
  line-height:1.1;
  letter-spacing:-.02em;
}
.hero-simple .lead{
  max-width:680px;
  margin:18px auto;
  font-size:17px;
  color:var(--muted);
}

/* Hero CTAs */
.hero-ctas{
  display:flex;
  gap:12px;
  margin-top:22px;
  flex-wrap:wrap;
}

/* Accessibility: Focus Visible */
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible{
  outline:2px solid var(--accent);
  outline-offset:2px;
}

/* Skip Link */
.skip-link{
  position:absolute;
  top:-40px;
  left:0;
  background:var(--accent);
  color:#fff;
  padding:8px 12px;
  text-decoration:none;
  z-index:100;
}
.skip-link:focus{
  top:0;
}

/* Publications grouped by research thread */
.pub-group{margin-top:14px}
.pub-group:first-child{margin-top:4px}
.pub-group-title{
  margin:0 0 4px 0;
  font-size:15px;
  padding-bottom:6px;
  border-bottom:1px solid var(--border);
  color:var(--accent);
}
#pubList > p.muted{margin:8px 0 0}

/* Collaborate section */
.highlight-card{
  border-left:4px solid var(--accent);
  margin-bottom:18px;
}
.sub-head{
  margin:22px 0 12px;
  font-size:17px;
}
.grid-3 .card h4, .grid-2 .card h4{margin:0 0 8px 0;font-size:15px}

/* Grid helpers */
.grid-2 h4, .grid-3 h4{
  margin:0 0 10px 0;
  font-size:16px;
}

@media (max-width: 920px){
  .hero{grid-template-columns:1fr; padding-top:22px}
  .nav{display:none}
  .grid-3{grid-template-columns:1fr}
  .professor-card{flex-direction:column;align-items:center;text-align:center}
  .professor-image{width:100px;height:100px}
  .professor-links{justify-content:center}
  .research-interests{justify-content:center}
}
@media (max-width: 640px){
  .grid-2{grid-template-columns:1fr}
  .contact-grid{grid-template-columns:1fr}
  .input{min-width:0; width:100%}
  .section-actions{width:100%}
  .hero-simple h1{font-size:36px}
  .hero-ctas{justify-content:center}
}