:root {
  --white: #f1f3f5;
  --off:   #f7f8fa;
  --ink:   #111318;
  --ink2:  #2a2d35;
  --ink3:  #5a5f6e;
  --ink4:  #9ba3b4;
  --blue:  #1a56db;
  --blue-lt: #eef3ff;
  --border: #e4e7ef;
  --border2: #cdd2e0;
  --f-sans: 'Inter', system-ui, sans-serif;
  --f-mono: 'JetBrains Mono', 'Courier New', monospace;
  --nav-h: 60px;
  --max: 1100px;
  --pad: clamp(1.25rem, 5vw, 2.5rem);
  --r: 5px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--white);
  color: var(--ink);
  font-family: var(--f-sans);
  font-weight: 300;
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }
strong { font-weight: 600; color: var(--ink2); }
button { cursor: pointer; border: none; background: none; font: inherit; }

/* ── Canvas background ─────────────────────────────── */
#bg {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: 1;
}

/* ── Nav ───────────────────────────────────────────── */
#nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--pad);
  background: rgba(255,255,255,0.93);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-name {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--ink2);
  letter-spacing: -0.01em;
}
#nav ul {
  display: flex;
  list-style: none;
  gap: 1.75rem;
}
#nav a {
  font-size: 0.88rem;
  font-weight: 400;
  color: var(--ink3);
  text-decoration: none;
  letter-spacing: 0.01em;
  transition: color 0.15s;
}
#nav a:hover { color: var(--blue); text-decoration: none; }

.burger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
}
.burger span { display: block; width: 20px; height: 1.5px; background: var(--ink2); }

/* ── Hero ──────────────────────────────────────────── */
#hero {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: var(--nav-h) var(--pad) 0;
}
.hero-inner { max-width: var(--max); margin: 0 auto; width: 100%; padding: 4rem 0; }

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--f-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: var(--blue);
  margin-bottom: 1.5rem;
  background: var(--blue-lt);
  padding: 0.35rem 0.9rem;
  border-radius: 100px;
  border: 1px solid rgba(26,86,219,0.18);
}
.tag-dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--blue);
  animation: blink 2s infinite;
}
@keyframes blink { 0%,100%{opacity:1} 50%{opacity:0.3} }

#hero h1 {
  font-size: clamp(3rem, 7vw, 5.5rem);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--ink);
  margin-bottom: 1.25rem;
}
#hero h1 span { color: var(--blue); }

.hero-desc {
  font-family: var(--f-mono);
  font-size: 0.88rem;
  color: var(--ink3);
  letter-spacing: 0.04em;
  margin-bottom: 2rem;
}

.hero-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 2.5rem;
}
.link-pill {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--ink2);
  padding: 0.55rem 1.1rem;
  border: 1px solid var(--border2);
  border-radius: 100px;
  text-decoration: none;
  transition: border-color 0.15s, color 0.15s;
}
.link-pill:hover { border-color: var(--blue); color: var(--blue); text-decoration: none; }

.hero-stats {
  display: flex;
  gap: 2.5rem;
  flex-wrap: wrap;
}
.hero-stats > div { display: flex; flex-direction: column; gap: 2px; }
.sn {
  font-size: 1.9rem;
  font-weight: 600;
  color: var(--ink);
  line-height: 1;
  letter-spacing: -0.02em;
}
.sl {
  font-family: var(--f-mono);
  font-size: 0.65rem;
  color: var(--ink4);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* ── Sections ──────────────────────────────────────── */
.section {
  position: relative;
  z-index: 1;
  padding: 5rem var(--pad);
  border-top: 1px solid var(--border);
}
.section-alt { background: var(--off); }

.container { max-width: var(--max); margin: 0 auto; }

.sec-title {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--ink);
  letter-spacing: -0.01em;
  margin-bottom: 2.25rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.sec-title::before {
  content: '';
  display: inline-block;
  width: 18px; height: 2px;
  background: var(--blue);
  border-radius: 2px;
}

/* Reveal */
.reveal { opacity: 0; transform: translateY(16px); transition: opacity 0.55s ease, transform 0.55s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ── About ─────────────────────────────────────────── */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 220px;
  gap: 4rem;
  align-items: start;
}
.about-bio p {
  color: var(--ink3);
  margin-bottom: 1rem;
  line-height: 1.75;
  font-size: 0.95rem;
}
.about-bio a { color: var(--blue); }
.about-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 1.25rem;
}
.about-tags span {
  font-family: var(--f-mono);
  font-size: 0.75rem;
  color: var(--blue);
  background: var(--blue-lt);
  padding: 0.25rem 0.65rem;
  border-radius: 3px;
  border: 1px solid rgba(26,86,219,0.15);
}

.about-info { display: flex; flex-direction: column; gap: 0; }
.info-block {
  padding: 0.7rem 0;
  border-bottom: 1px solid var(--border);
}
.info-block:first-child { border-top: 1px solid var(--border); }
.ib-label {
  font-family: var(--f-mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink4);
  margin-bottom: 0.15rem;
}
.ib-val { font-size: 0.9rem; color: var(--ink2); }
.ib-val a { color: var(--blue); text-decoration: none; }
.ib-val a:hover { text-decoration: underline; }

/* ── Research cards ───────────────────────────────── */
.cards-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: var(--r);
  overflow: hidden;
}
.card {
  background: var(--white);
  padding: 1.75rem;
  position: relative;
  transition: background 0.15s;
}
.section-alt .card { background: var(--off); }
.card:hover { background: var(--white); }

.card-num {
  font-family: var(--f-mono);
  font-size: 0.7rem;
  color: var(--ink4);
  letter-spacing: 0.08em;
  margin-bottom: 1rem;
}
.card-icon {
  width: 36px; height: 36px;
  color: var(--blue);
  margin-bottom: 0.9rem;
  opacity: 0.85;
}
.card h3 {
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 0.5rem;
}
.card p {
  font-size: 0.86rem;
  color: var(--ink3);
  line-height: 1.65;
}

/* ── Publications ─────────────────────────────────── */
.pub-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1.5rem;
}
.pub-filters { display: flex; gap: 0.35rem; }
.pf {
  font-family: var(--f-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  padding: 0.35rem 0.85rem;
  border: 1px solid var(--border2);
  border-radius: 100px;
  color: var(--ink4);
  transition: all 0.15s;
}
.pf:hover { border-color: var(--blue); color: var(--blue); }
.pf.active { background: var(--blue); border-color: var(--blue); color: #fff; }

.pub-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
}
.pub-table tr {
  border-bottom: 1px solid var(--border);
  transition: background 0.12s;
}
.pub-table tr:first-child { border-top: 2px solid var(--ink2); }
.pub-table tr:hover { background: var(--off); }
.pub-table tr.hidden { display: none; }
.pub-table td { padding: 1rem 0.6rem; vertical-align: top; }

.pt-year {
  font-family: var(--f-mono);
  font-size: 0.8rem;
  font-weight: 400;
  color: var(--blue);
  white-space: nowrap;
  width: 48px;
  padding-right: 0;
}
.pt-venue {
  font-family: var(--f-mono);
  font-size: 0.72rem;
  color: var(--ink4);
  white-space: nowrap;
  width: 110px;
  letter-spacing: 0.03em;
}
.pt-title {
  font-size: 0.88rem;
  color: var(--ink2);
  font-weight: 400;
  line-height: 1.45;
}
.pt-authors {
  font-size: 0.78rem;
  color: var(--ink4);
  width: 160px;
  font-style: italic;
}
.pt-link a {
  font-family: var(--f-mono);
  font-size: 0.75rem;
  color: var(--blue);
  white-space: nowrap;
  text-decoration: none;
}
.pt-link a:hover { text-decoration: underline; }

.pub-more {
  margin-top: 1.5rem;
  display: flex;
  gap: 2rem;
  font-size: 0.8rem;
}
.pub-more a { color: var(--blue); }

/* ── Projects ─────────────────────────────────────── */
.proj-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  border-top: 2px solid var(--ink2);
}
.proj-item {
  display: grid;
  grid-template-columns: 220px 1fr auto;
  gap: 1rem 2.5rem;
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--border);
  align-items: start;
  transition: background 0.12s;
  border-radius: 3px;
}
.proj-item:hover { background: var(--white); padding-left: 0.5rem; }
.proj-item--lead { background: var(--blue-lt); padding: 1.5rem; border-radius: var(--r); border: 1px solid rgba(26,86,219,0.15); margin-bottom: 0; }
.proj-item--lead:hover { background: var(--blue-lt); padding-left: 1.5rem; }

.pi-left { display: flex; flex-direction: column; gap: 0.25rem; }
.pi-badge {
  font-family: var(--f-mono);
  font-size: 0.66rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.2rem 0.55rem;
  border-radius: 3px;
  display: inline-block;
  align-self: flex-start;
  margin-bottom: 0.25rem;
}
.pi-badge--fnr  { background: #fef3c7; color: #92400e; }
.pi-badge--list { background: #dbeafe; color: #1e40af; }
.pi-badge--res  { background: #d1fae5; color: #065f46; }
.pi-badge--phd  { background: #ede9fe; color: #5b21b6; }

.pi-left h3 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--ink);
}
.pi-sub {
  font-size: 0.82rem;
  color: var(--ink3);
  font-style: italic;
}
.pi-desc {
  font-size: 0.88rem;
  color: var(--ink3);
  line-height: 1.65;
  align-self: center;
}
.pi-link {
  font-family: var(--f-mono);
  font-size: 0.78rem;
  color: var(--blue);
  white-space: nowrap;
  text-decoration: none;
  align-self: start;
  padding-top: 0.15rem;
}
.pi-link:hover { text-decoration: underline; }

/* ── Contact ──────────────────────────────────────── */
.contact-grid {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 4rem;
  align-items: start;
}
.contact-intro {
  font-size: 0.95rem;
  color: var(--ink3);
  line-height: 1.7;
  margin-top: 0.25rem;
}

.contact-links {
  display: flex;
  flex-direction: column;
  gap: 0;
  border-top: 2px solid var(--ink2);
}
.contact-row {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--border);
  text-decoration: none;
  transition: background 0.12s;
  border-radius: 3px;
}
.contact-row:hover { background: var(--off); padding-left: 0.5rem; text-decoration: none; }
.cr-label {
  font-family: var(--f-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink4);
  width: 65px;
  flex-shrink: 0;
}
.cr-val { flex: 1; font-size: 0.9rem; color: var(--ink2); }
.cr-arr { font-size: 0.9rem; color: var(--blue); }

/* ── Footer ───────────────────────────────────────── */
footer {
  position: relative;
  z-index: 1;
  border-top: 1px solid var(--border);
  padding: 1.5rem var(--pad);
  background: var(--white);
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.75rem;
  color: var(--ink4);
}
.footer-mono { font-family: var(--f-mono); font-size: 0.68rem; }

/* ── Project video thumbnail ──────────────────────── */
.proj-video-thumb {
  grid-column: 1 / -1;
  position: relative;
  display: block;
  margin-top: 1rem;
  border-radius: 6px;
  overflow: hidden;
  width: 320px;
  max-width: 100%;
  aspect-ratio: 16 / 9;
  text-decoration: none;
  background: var(--ink);
}
.proj-video-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: opacity 0.2s, transform 0.3s;
  opacity: 0.88;
}
.proj-video-thumb:hover img {
  opacity: 0.7;
  transform: scale(1.02);
}
.pvt-play {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: none;
}
.pvt-play svg {
  filter: drop-shadow(0 2px 8px rgba(0,0,0,0.5));
  transition: transform 0.2s;
}
.proj-video-thumb:hover .pvt-play svg {
  transform: scale(1.12);
}
.pvt-label {
  position: absolute;
  bottom: 0.6rem;
  right: 0.75rem;
  font-family: var(--f-mono);
  font-size: 0.68rem;
  color: #fff;
  background: rgba(0,0,0,0.55);
  padding: 0.2rem 0.5rem;
  border-radius: 3px;
  letter-spacing: 0.04em;
}

/* ── Responsive ───────────────────────────────────── */
@media (max-width: 900px) {
  .cards-4 { grid-template-columns: 1fr 1fr; }
  .about-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; gap: 2rem; }
  .pub-table .pt-authors { display: none; }
  .proj-item { grid-template-columns: 1fr 1fr; }
  .proj-item .pi-desc { grid-column: 1 / -1; }
}
@media (max-width: 600px) {
  :root { --nav-h: 56px; }

  #nav ul { display: none; }
  #nav ul.open {
    display: flex;
    flex-direction: column;
    position: fixed;
    inset: var(--nav-h) 0 0 0;
    background: var(--white);
    padding: 2rem var(--pad);
    gap: 1.5rem;
    z-index: 99;
    border-top: 1px solid var(--border);
  }
  #nav ul.open a { font-size: 1.05rem; }
  .burger { display: flex; }

  /* Hero */
  #hero h1 { font-size: clamp(2.4rem, 10vw, 3.5rem); }
  .hero-desc { font-size: 0.85rem; }
  .hero-tag { font-size: 0.75rem; }
  .link-pill { font-size: 0.88rem; padding: 0.6rem 1.1rem; }

  /* Sections */
  .section { padding: 3.5rem var(--pad); }
  .sec-title { font-size: 1.1rem; }

  /* Research cards */
  .cards-4 { grid-template-columns: 1fr; }
  .card { padding: 1.4rem; }
  .card h3 { font-size: 1rem; }
  .card p { font-size: 0.9rem; }

  /* Publications */
  .pub-header { flex-direction: column; align-items: flex-start; }
  .pub-filters { flex-wrap: wrap; }
  .pf { font-size: 0.78rem; padding: 0.4rem 0.9rem; }
  .pub-table .pt-venue { display: none; }
  .pub-table .pt-title { font-size: 0.88rem; }
  .pub-table .pt-year { font-size: 0.8rem; }
  .pt-link a { font-size: 0.78rem; }
  .pub-more { flex-direction: column; gap: 0.75rem; font-size: 0.88rem; }

  /* Projects */
  .proj-item { grid-template-columns: 1fr; }
  .proj-item--lead { padding: 1.25rem; }
  .pi-left h3 { font-size: 1.05rem; }
  .pi-desc { font-size: 0.88rem; }
  .pi-link { font-size: 0.82rem; }

  /* About */
  .about-bio p { font-size: 0.95rem; }
  .ib-val { font-size: 0.92rem; }

  /* Contact */
  .cr-val { font-size: 0.88rem; }
  .contact-intro { font-size: 0.92rem; }

  /* Footer */
  .footer-mono { display: none; }
  .hero-stats { gap: 1.5rem; }
}