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

:root {
  --navy:   #1a2744;
  --navy2:  #243560;
  --accent: #2e6da4;
  --text:   #222831;
  --muted:  #5a6378;
  --light:  #f5f7fb;
  --white:  #ffffff;
  --border: #dde3ef;
  --radius: 8px;
  --max-w:  900px;
  --transition: 0.2s ease;
}

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: 'Inter', sans-serif;
  color: var(--text);
  background: var(--white);
  line-height: 1.7;
}

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

/* ── Navigation ── */
#site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

nav {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 2rem;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-name {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--navy);
  letter-spacing: 0.01em;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 2rem;
}

.nav-links a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--muted);
  transition: color var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--navy);
  text-decoration: none;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.4rem;
  cursor: pointer;
  color: var(--navy);
}

/* ── Sections ── */
section { padding: 5rem 2rem; }
section:nth-child(even) { background: var(--light); }

.section-inner {
  max-width: var(--max-w);
  margin: 0 auto;
}

.section-title {
  font-family: 'Lora', serif;
  font-size: 1.75rem;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 1.25rem;
  padding-bottom: 0.6rem;
  position: relative;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 48px;
  height: 3px;
  background: var(--accent);
  border-radius: 2px;
}

.section-intro {
  color: var(--muted);
  margin-bottom: 2.5rem;
  max-width: 680px;
}

.stat-num {
  color: var(--navy);
  font-weight: 600;
}

/* ── About ── */
#about {
  padding-top: 5rem;
  padding-bottom: 5rem;
  background: var(--white);
}

.about-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: flex;
  align-items: flex-start;
  gap: 3rem;
}

.about-photo {
  flex-shrink: 0;
}

.about-photo img {
  width: 180px;
  height: 180px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--border);
}

.photo-placeholder {
  display: none;
  width: 180px;
  height: 180px;
  border-radius: 50%;
  background: var(--navy);
  color: white;
  font-size: 2.5rem;
  font-weight: 600;
  align-items: center;
  justify-content: center;
  letter-spacing: 0.05em;
}

.about-text h1 {
  font-family: 'Lora', serif;
  font-size: 2.2rem;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 0.25rem;
}

.degree {
  font-size: 1.1rem;
  font-weight: 400;
  color: var(--muted);
}

.affiliation {
  font-size: 0.95rem;
  color: var(--muted);
  margin-top: 0.15rem;
  margin-bottom: 1rem;
}

.bio {
  font-size: 0.95rem;
  color: var(--text);
  margin-bottom: 0.5rem;
  max-width: 600px;
}

.about-metrics {
  font-size: 0.85rem;
  color: var(--muted);
  margin-bottom: 1.1rem;
}

.about-metrics strong {
  color: var(--navy);
  font-weight: 600;
}

/* ── Bio Tags ── */
.bio-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1.25rem;
}

.bio-tag {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--accent);
  background: rgba(46, 109, 164, 0.07);
  border: 1px solid rgba(46, 109, 164, 0.2);
  border-radius: 4px;
  padding: 0.2rem 0.55rem;
  letter-spacing: 0.01em;
}

/* ── Social Buttons ── */
.social-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.social-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.4rem 0.9rem;
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--navy);
  background: var(--white);
  transition: background var(--transition), border-color var(--transition), color var(--transition);
}

.social-btn svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}

.social-btn:hover {
  background: var(--navy);
  color: var(--white);
  border-color: var(--navy);
  text-decoration: none;
}

/* ── News ── */
.news-list {
  display: flex;
  flex-direction: column;
}

.news-item {
  display: flex;
  gap: 1.5rem;
  padding: 0.7rem 0;
  border-bottom: 1px solid var(--border);
  align-items: baseline;
}

.news-item:first-child {
  border-top: 1px solid var(--border);
}

.news-date {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--muted);
  min-width: 72px;
  flex-shrink: 0;
}

.news-text {
  font-size: 0.9rem;
  color: var(--text);
  line-height: 1.55;
}

/* ── Research Cards ── */
.research-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.research-card {
  background: var(--light);
  border: 1px solid var(--border);
  border-top: 2px solid var(--accent);
  border-radius: var(--radius);
  padding: 1.75rem;
  transition: box-shadow var(--transition), transform var(--transition);
}

.research-card:hover {
  box-shadow: 0 4px 20px rgba(26,39,68,0.08);
  transform: translateY(-2px);
}

.card-icon {
  width: 28px;
  height: 28px;
  color: var(--accent);
  margin-bottom: 0.75rem;
}

.card-icon svg {
  width: 100%;
  height: 100%;
  display: block;
}

.research-card h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 0.5rem;
}

.research-card p {
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.65;
}

.card-paper-count {
  display: inline-block;
  margin-top: 0.85rem;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--accent);
  transition: opacity var(--transition);
}

.card-paper-count:hover {
  opacity: 0.75;
  text-decoration: underline;
}

.card-status {
  display: inline-block;
  margin-top: 0.85rem;
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--muted);
  letter-spacing: 0.01em;
}

/* ── Publications ── */
.pub-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.pub-item {
  padding: 1.25rem 0 1.25rem 0.75rem;
  border-left: 3px solid transparent;
  border-bottom: 1px solid var(--border);
  transition: border-left-color var(--transition), background var(--transition);
}

.pub-item:first-child { border-top: 1px solid var(--border); }

.pub-item:hover {
  border-left-color: var(--accent);
  background: rgba(255, 255, 255, 0.75);
}

.pub-item.pub-featured {
  border-left-color: var(--accent);
  background: rgba(46, 109, 164, 0.05);
}

.pub-venue {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--accent);
  margin-bottom: 0.3rem;
}

.pub-title {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--navy);
  margin-bottom: 0.2rem;
}

.pub-title a {
  color: var(--navy);
  font-weight: 500;
}

.pub-title a:hover {
  color: var(--accent);
  text-decoration: underline;
}

.pub-authors {
  font-size: 0.825rem;
  color: var(--muted);
  margin-bottom: 0.2rem;
}

.pub-authors strong {
  color: var(--text);
  font-weight: 600;
}

.pub-teaser {
  font-size: 0.825rem;
  color: var(--muted);
  font-style: italic;
  line-height: 1.55;
  margin-bottom: 0.5rem;
}

.pub-badge {
  display: inline-block;
  font-size: 0.65rem;
  font-weight: 700;
  font-style: normal;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  padding: 0.1rem 0.45rem;
  border-radius: 3px;
  margin-left: 0.5rem;
  vertical-align: middle;
  position: relative;
  top: -1px;
}

.pub-badge--new {
  background: rgba(46,109,164,0.1);
  color: var(--accent);
  border: 1px solid rgba(46,109,164,0.25);
}

.pub-badge--review {
  background: var(--light);
  color: var(--muted);
  border: 1px solid var(--border);
}

.pub-links { display: flex; gap: 0.5rem; }

.pub-link {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 4px;
  padding: 0.15rem 0.5rem;
  transition: background var(--transition), color var(--transition);
}

.pub-link:hover {
  background: var(--accent);
  color: var(--white);
  text-decoration: none;
}

.pub-link--preprint {
  color: var(--muted);
  border-color: var(--border);
}

.pub-link--preprint:hover {
  background: var(--muted);
  border-color: var(--muted);
}

.pub-note {
  margin-top: 1.5rem;
  font-size: 0.825rem;
  color: var(--muted);
}

/* ── CV ── */
.cv-block {
  position: relative;
  margin-bottom: 2.5rem;
  padding-left: 1.25rem;
  border-left: 2px solid var(--border);
}

.cv-category {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  margin-bottom: 1rem;
}

.cv-entry {
  position: relative;
  display: flex;
  gap: 1.5rem;
  margin-bottom: 1rem;
  align-items: flex-start;
}

.cv-entry::before {
  content: '';
  position: absolute;
  left: calc(-1.25rem - 5px);
  top: 0.35rem;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--white);
  border: 2px solid var(--accent);
}

.cv-date {
  font-size: 0.8rem;
  color: var(--muted);
  min-width: 100px;
  padding-top: 0.1rem;
  flex-shrink: 0;
}

.cv-detail {
  font-size: 0.9rem;
  color: var(--text);
  line-height: 1.6;
}

.cv-sub {
  font-size: 0.825rem;
  color: var(--muted);
}

.cv-download-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 1rem;
  padding: 0.65rem 1.5rem;
  background: var(--navy);
  color: var(--white);
  border-radius: var(--radius);
  font-size: 0.875rem;
  font-weight: 500;
  transition: background var(--transition);
}

.cv-download-btn:hover {
  background: var(--navy2);
  text-decoration: none;
}

/* ── Contact ── */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
}

.contact-block h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 1rem;
}

.contact-block p {
  font-size: 0.9rem;
  color: var(--muted);
  margin-bottom: 0.75rem;
}

.contact-block strong {
  color: var(--text);
}

.contact-links-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.contact-links-list a {
  font-size: 0.9rem;
  color: var(--accent);
}

/* ── Footer ── */
footer {
  background: var(--navy);
  color: rgba(255,255,255,0.5);
  text-align: center;
  padding: 1.5rem 2rem;
  font-size: 0.8rem;
}

/* ── Scroll Reveal ── */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.reveal.in-view {
  opacity: 1;
  transform: none;
}

.research-grid .reveal:nth-child(2) { transition-delay: 0.1s; }
.research-grid .reveal:nth-child(3) { transition-delay: 0.2s; }

.news-list .reveal:nth-child(2) { transition-delay: 0.07s; }
.news-list .reveal:nth-child(3) { transition-delay: 0.14s; }
.news-list .reveal:nth-child(4) { transition-delay: 0.21s; }

.pub-list .reveal:nth-child(2) { transition-delay: 0.06s; }
.pub-list .reveal:nth-child(3) { transition-delay: 0.12s; }
.pub-list .reveal:nth-child(4) { transition-delay: 0.18s; }
.pub-list .reveal:nth-child(5) { transition-delay: 0.24s; }
.pub-list .reveal:nth-child(6) { transition-delay: 0.30s; }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* ── Mobile ── */
@media (max-width: 680px) {
  .nav-links { display: none; }
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    background: var(--white);
    border-bottom: 1px solid var(--border);
    padding: 1rem 2rem;
    gap: 1rem;
  }
  .nav-toggle { display: block; }

  .about-inner { flex-direction: column; align-items: center; text-align: center; gap: 1.5rem; }
  .social-links { justify-content: center; }
  .bio-tags { justify-content: center; }
  .bio { max-width: 100%; }

  .research-grid { grid-template-columns: 1fr; }

  .news-item { flex-direction: column; gap: 0.1rem; }
  .news-date { min-width: unset; }

  .contact-grid { grid-template-columns: 1fr; gap: 2rem; }

  .cv-entry { flex-direction: column; gap: 0.2rem; }
  .cv-date { min-width: unset; }
}