/* =============================================================
   DESIGN TOKENS — Change colors/fonts here to restyle the whole site
   ============================================================= */
:root {
  --ink:          #1a1a2e;
  --ink-light:    #4a4a6a;
  --ink-muted:    #7a7a9a;
  --accent:       #8b0000;
  --accent-mid:   #b30000;
  --accent-soft:  #fff0f0;
  --gold:         #c8961a;
  --gold-bg:      #fff8e1;
  --gold-border:  #f0d070;
  --blue:         #1a3a8b;
  --blue-bg:      #e8f0fe;
  --blue-border:  #c0d0f8;
  --green:        #2e7d32;
  --green-bg:     #e8f5e9;
  --green-border: #b0d8b2;
  --purple:       #7b1fa2;
  --purple-bg:    #f3e5f5;
  --purple-border:#d8b0e0;
  --bg:           #fafafa;
  --bg-card:      #ffffff;
  --border:       #e8e8f0;
  --border-dark:  #c8c8e0;
  --radius:       8px;
  --shadow-sm:    0 2px 8px rgba(26,26,46,0.07);
  --shadow-md:    0 6px 24px rgba(26,26,46,0.10);
  --nav-h:        60px;
  --max-w:        900px;
  --font-display: 'DM Serif Display', Georgia, serif;
  --font-body:    'DM Sans', -apple-system, sans-serif;
}

/* =============================================================
   RESET & BASE
   ============================================================= */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
::selection { background: var(--accent); color: white; }

/* =============================================================
   NAVBAR
   ============================================================= */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  height: var(--nav-h);
  background: rgba(250,250,250,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex; align-items: center; justify-content: space-between;
}
.nav-logo {
  font-family: var(--font-display);
  font-size: 1.1rem;
  color: var(--accent);
  display: flex; align-items: center; gap: 7px;
}
.nav-penguin {
  height: 32px; width: auto;
  display: block;
  filter: drop-shadow(0 1px 2px rgba(0,0,0,0.15));
}
.nav-links {
  display: flex; gap: 4px; list-style: none;
}
.nav-links a {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--ink-light);
  padding: 6px 13px;
  border-radius: 20px;
  transition: background 0.18s, color 0.18s;
}
.nav-links a:hover,
.nav-links a.active {
  background: var(--accent-soft);
  color: var(--accent);
}
.nav-cv {
  font-weight: 600 !important;
  color: white !important;
  background: var(--accent) !important;
}
.nav-cv:hover { background: var(--accent-mid) !important; }

.nav-hamburger {
  display: none;
  background: none; border: none;
  cursor: pointer; padding: 8px;
  color: var(--ink); font-size: 1.2rem;
}
.mobile-menu {
  display: none; position: fixed;
  top: var(--nav-h); left: 0; right: 0;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  padding: 16px 24px; z-index: 99;
  flex-direction: column; gap: 4px;
}
.mobile-menu.open { display: flex; }
.mobile-menu a {
  padding: 10px 12px; border-radius: var(--radius);
  font-weight: 500; color: var(--ink-light);
  transition: all 0.18s;
}
.mobile-menu a:hover { background: var(--accent-soft); color: var(--accent); }

/* =============================================================
   PAGE LAYOUT
   ============================================================= */
main {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: calc(var(--nav-h) + 28px) 24px 0;
}
section { padding-top: 56px; }
section:last-of-type { padding-bottom: 40px; }

.section-header {
  display: flex; align-items: baseline; gap: 12px;
  margin-bottom: 32px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--border);
}
.section-header h2 {
  font-family: var(--font-display);
  font-size: 1.8rem; font-weight: 400;
}
.section-count {
  font-size: 0.75rem; font-weight: 700;
  color: var(--ink-muted);
  background: var(--border);
  padding: 2px 9px; border-radius: 20px;
  letter-spacing: 0.05em; text-transform: uppercase;
}

/* =============================================================
   ABOUT SECTION
   ============================================================= */
.about-grid {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 40px; align-items: start;
}
.about-photo-wrap {
  display: flex; flex-direction: column;
  align-items: center; gap: 16px;
}
.about-photo {
  width: 200px; height: 200px;
  border-radius: 50%;
  object-fit: cover;
  object-position: center top;
  box-shadow: 0 0 0 4px white, 0 0 0 6px var(--border-dark), var(--shadow-md);
}
.about-photo-wrap .social-links {
  flex-direction: column; width: 100%; gap: 6px;
}
.about-photo-wrap .social-link {
  justify-content: center;
  font-size: 0.78rem; padding: 6px 8px;
}
.about-name {
  font-family: var(--font-display);
  font-size: 2rem; font-weight: 400;
  line-height: 1.15; margin-bottom: 5px;
}
.about-role {
  font-size: 0.92rem; color: var(--ink-light);
  margin-bottom: 20px;
}
.about-role strong a { color: var(--accent); font-weight: 600; }
.research-tags {
  display: flex; flex-wrap: wrap; gap: 7px;
  margin-bottom: 18px;
}
.tag {
  font-size: 0.76rem; font-weight: 500;
  padding: 3px 11px; border-radius: 20px;
  background: var(--accent-soft);
  color: var(--accent);
  border: 1px solid #f0c0c0;
}
.about-bio {
  font-size: 0.95rem; color: var(--ink-light);
  line-height: 1.75;
  text-align: justify;
}
.about-bio p { margin-bottom: 14px; }
.about-bio p:last-child { margin-bottom: 0; }
.about-bio a { color: var(--blue); border-bottom: 1px solid transparent; }
.about-bio a:hover { border-bottom-color: var(--blue); }
.social-links {
  display: flex; gap: 8px; flex-wrap: wrap;
}
.social-link {
  display: flex; align-items: center; gap: 6px;
  font-size: 0.82rem; font-weight: 500;
  color: var(--ink-light);
  padding: 6px 12px; border-radius: 20px;
  border: 1px solid var(--border-dark);
  transition: all 0.18s;
}
.social-link:hover {
  border-color: var(--accent); color: var(--accent);
  background: var(--accent-soft);
}

/* =============================================================
   FILTER BARS (shared by news and papers)
   ============================================================= */
.filter-bar {
  display: flex; gap: 7px; flex-wrap: wrap;
  margin-bottom: 20px;
}
.filter-btn {
  font-size: 0.78rem; font-weight: 600;
  padding: 5px 13px; border-radius: 20px;
  border: 1px solid var(--border-dark);
  background: transparent; color: var(--ink-light);
  cursor: pointer; transition: all 0.18s;
  letter-spacing: 0.02em;
}
.filter-btn:hover, .filter-btn.active {
  background: var(--accent); border-color: var(--accent); color: white;
}
.toggle-btn {
  margin-top: 14px;
  background: none; border: 1px solid var(--border-dark);
  color: var(--ink-light); font-size: 0.83rem; font-weight: 500;
  padding: 8px 20px; border-radius: 20px;
  cursor: pointer; transition: all 0.18s;
}
.toggle-btn:hover {
  background: var(--accent-soft); border-color: var(--accent); color: var(--accent);
}

/* =============================================================
   NEWS SECTION
   ============================================================= */
.news-list { display: flex; flex-direction: column; }
.news-item {
  display: grid; grid-template-columns: 52px 1fr;
  gap: 0 16px; padding: 13px 0;
  border-bottom: 1px solid var(--border);
  align-items: start;
  transition: opacity 0.2s;
}
.news-item.hidden { display: none; }
.news-item:last-child { border-bottom: none; }
.news-year {
  font-size: 0.74rem; font-weight: 700;
  color: var(--ink-muted); letter-spacing: 0.06em;
  text-transform: uppercase; padding-top: 3px;
}
.news-body {
  font-size: 0.905rem; color: var(--ink-light); line-height: 1.6;
}
.news-body a { color: var(--blue); font-weight: 500; }
.news-body a:hover { text-decoration: underline; }
.news-badge {
  display: inline-flex; align-items: center; gap: 3px;
  font-size: 0.7rem; font-weight: 700;
  padding: 2px 7px; border-radius: 10px;
  margin-left: 6px; vertical-align: middle;
  letter-spacing: 0.02em;
}
.badge-award   { background: var(--gold-bg);   color: var(--gold);   border: 1px solid var(--gold-border); }
.badge-paper   { background: var(--blue-bg);   color: var(--blue);   border: 1px solid var(--blue-border); }
.badge-service { background: var(--green-bg);  color: var(--green);  border: 1px solid var(--green-border); }
.badge-talk    { background: var(--purple-bg); color: var(--purple); border: 1px solid var(--purple-border); }
.badge-poster  { background: #e0f7fa;          color: #00796b;       border: 1px solid #80cbc4; }
.badge-venue   { background: var(--green-bg);  color: var(--green);     border: 1px solid var(--green-border); }
.badge-other   { background: var(--border);    color: var(--ink-muted); border: 1px solid var(--border-dark); }


/* =============================================================
   PUBLICATIONS SECTION
   ============================================================= */
.year-group { margin-bottom: 36px; }
.year-group.hidden { display: none; }

.year-label {
  font-family: var(--font-display);
  font-size: 1.2rem; color: var(--accent);
  margin-bottom: 12px;
  display: flex; align-items: center; gap: 12px;
}
.year-label::after {
  content: ''; flex: 1; height: 1px; background: var(--border);
}

.paper-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 17px 20px;
  margin-bottom: 10px;
  transition: border-color 0.18s, box-shadow 0.18s;
}
.paper-card:hover {
  border-color: var(--border-dark);
  box-shadow: var(--shadow-sm);
}
.paper-award { border-left: 3px solid var(--gold); }

.paper-top-row {
  display: flex; align-items: center;
  justify-content: space-between; flex-wrap: wrap;
  gap: 8px; margin-bottom: 7px;
}
.paper-venue-badge {
  display: inline-block;
  font-size: 0.7rem; font-weight: 700;
  padding: 2px 9px; border-radius: 10px;
  background: var(--ink); color: white;
  letter-spacing: 0.07em; text-transform: uppercase;
}
.paper-award-badge {
  display: inline-flex; align-items: center; gap: 4px;
  font-size: 0.7rem; font-weight: 700;
  color: var(--gold); background: var(--gold-bg);
  border: 1px solid var(--gold-border);
  padding: 2px 9px; border-radius: 10px;
}
.paper-title {
  font-size: 0.975rem; font-weight: 600;
  color: var(--blue); line-height: 1.4;
  margin-bottom: 5px;
}
.paper-title a:hover { text-decoration: underline; }
.paper-authors {
  font-size: 0.84rem; color: var(--ink-light);
  margin-bottom: 5px; line-height: 1.5;
}
.paper-authors .me,
.paper-authors strong.me { font-weight: 700; color: var(--ink); }
.paper-venue-full {
  font-size: 0.79rem; color: var(--ink-muted);
  font-style: italic; margin-bottom: 10px;
}
.paper-links { display: flex; gap: 7px; flex-wrap: wrap; }
.paper-link {
  font-size: 0.73rem; font-weight: 700;
  padding: 3px 9px; border-radius: 10px;
  border: 1px solid var(--border-dark);
  color: var(--accent);
  transition: all 0.18s;
  text-transform: uppercase; letter-spacing: 0.04em;
}
.paper-link:hover {
  background: var(--accent); border-color: var(--accent); color: white;
}

/* =============================================================
   DISSERTATION CARD
   ============================================================= */
.dissertation-card {
  background: linear-gradient(135deg, #1a1a2e 0%, #2d1a2e 100%);
  border-radius: var(--radius);
  padding: 26px 30px;
  color: white; margin-top: 32px;
  position: relative; overflow: hidden;
}
.dissertation-card::before {
  content: '"';
  position: absolute; right: 20px; top: -16px;
  font-family: var(--font-display);
  font-size: 9rem; color: rgba(255,255,255,0.05);
  line-height: 1; pointer-events: none;
}
.dissertation-label {
  font-size: 0.7rem; font-weight: 700;
  letter-spacing: 0.12em; text-transform: uppercase;
  color: rgba(255,255,255,0.45); margin-bottom: 10px;
}
.dissertation-title {
  font-family: var(--font-display);
  font-size: 1.2rem; font-weight: 400;
  margin-bottom: 14px; line-height: 1.4;
}
.dissertation-title a { color: white; }
.dissertation-title a:hover { text-decoration: underline; }
.dissertation-thesis {
  font-size: 0.845rem; color: rgba(255,255,255,0.65);
  font-style: italic; line-height: 1.7;
  border-left: 2px solid rgba(255,255,255,0.2);
  padding-left: 14px; margin: 0 0 18px;
}
.dissertation-links { display: flex; gap: 8px; }
.dissertation-link {
  font-size: 0.75rem; font-weight: 600;
  padding: 5px 13px; border-radius: 10px;
  border: 1px solid rgba(255,255,255,0.22);
  color: rgba(255,255,255,0.82);
  transition: background 0.18s; text-transform: uppercase; letter-spacing: 0.04em;
}
.dissertation-link:hover { background: rgba(255,255,255,0.12); }

/* =============================================================
   CONTACT SECTION
   ============================================================= */
.contact-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 10px;
}
.contact-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
  display: flex; gap: 10px; align-items: center;
  transition: border-color 0.18s, box-shadow 0.18s;
  cursor: pointer;
}
.contact-card:hover {
  border-color: var(--accent); box-shadow: var(--shadow-sm);
}
.contact-icon {
  width: 30px; height: 30px; border-radius: 8px;
  background: var(--accent-soft);
  display: flex; align-items: center; justify-content: center;
  color: var(--accent); font-size: 0.8rem; flex-shrink: 0;
}
.contact-label {
  font-size: 0.65rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--ink-muted); margin-bottom: 2px;
}
.contact-value {
  font-size: 0.8rem; font-weight: 500; color: var(--ink);
  word-break: break-word;
}

/* =============================================================
   FOOTER
   ============================================================= */
footer {
  border-top: 1px solid var(--border);
  padding: 20px 24px; text-align: center;
  color: var(--ink-muted); font-size: 0.8rem;
  max-width: var(--max-w); margin: 0 auto;
}
.footer-sub { margin-top: 3px; font-size: 0.76rem; color: #aaa; }

/* =============================================================
   VENUE CHIPS (about section)
   ============================================================= */
.venue-counts {
  display: flex; flex-wrap: wrap; gap: 6px;
  margin: 10px 0 14px;
}
.venue-chip {
  display: inline-flex; align-items: center; gap: 4px;
  background: var(--accent-soft); color: var(--accent);
  border: 1px solid color-mix(in srgb, var(--accent) 20%, transparent);
  border-radius: 6px; padding: 3px 9px;
  font-size: 0.72rem; font-weight: 600; letter-spacing: 0.03em;
  white-space: nowrap;
}
.venue-chip strong { font-weight: 800; }

/* =============================================================
   SCHOLAR CITATION BADGE
   ============================================================= */
.scholar-count {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  font-size: 0.65rem; font-weight: 700;
  border-radius: 20px;
  padding: 1px 6px;
  margin-left: 4px;
  vertical-align: middle;
  line-height: 1.5;
  opacity: 0;
  transition: opacity 0.3s;
}
.scholar-count.loaded { opacity: 1; }

/* =============================================================
   COPY EMAIL TOOLTIP
   ============================================================= */
.contact-card { position: relative; }
.copy-tooltip {
  position: absolute; bottom: calc(100% + 6px); left: 50%;
  transform: translateX(-50%) translateY(4px);
  background: var(--ink); color: #fff;
  font-size: 0.7rem; font-weight: 600;
  padding: 4px 10px; border-radius: 6px;
  white-space: nowrap; pointer-events: none;
  opacity: 0; transition: opacity 0.2s, transform 0.2s;
}
.copy-tooltip::after {
  content: '';
  position: absolute; top: 100%; left: 50%;
  transform: translateX(-50%);
  border: 5px solid transparent;
  border-top-color: var(--ink);
}
.contact-card.copied .copy-tooltip {
  opacity: 1; transform: translateX(-50%) translateY(0);
}

/* =============================================================
   SERVICE SECTION
   ============================================================= */
.service-block { margin-bottom: 24px; }
.service-block:last-child { margin-bottom: 0; }
.service-role-label {
  display: flex; align-items: center; gap: 7px;
  font-size: 0.78rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--ink-muted); margin-bottom: 12px;
}
.service-role-label i { color: var(--accent); font-size: 0.85rem; }
.service-pc-grid {
  display: flex; flex-direction: column; gap: 10px;
}
.service-pc-row {
  display: grid; grid-template-columns: 72px 1fr;
  gap: 10px; align-items: flex-start;
}
.service-pc-conf {
  font-size: 0.78rem; font-weight: 700;
  color: var(--ink); padding-top: 5px;
  text-align: right;
}
.service-tags {
  display: flex; flex-wrap: wrap; gap: 7px;
}
.service-tag {
  display: inline-block;
  background: var(--bg-card); color: var(--ink);
  border: 1px solid var(--border);
  border-radius: 6px; padding: 4px 11px;
  font-size: 0.78rem; font-weight: 500;
  text-decoration: none;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}
.service-tag:hover {
  background: var(--accent-soft); border-color: var(--accent);
  color: var(--accent);
}

/* =============================================================
   BACK-TO-TOP BUTTON
   ============================================================= */
.back-to-top {
  position: fixed; bottom: 28px; right: 28px; z-index: 900;
  width: 40px; height: 40px; border-radius: 50%;
  background: var(--accent); color: #fff;
  border: none; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.85rem;
  box-shadow: 0 2px 10px rgba(0,0,0,0.2);
  opacity: 0; pointer-events: none;
  transition: opacity 0.25s, transform 0.25s;
  transform: translateY(8px);
}
.back-to-top.visible {
  opacity: 1; pointer-events: auto; transform: translateY(0);
}
.back-to-top:hover { background: var(--accent-dark, #6b0000); }

/* =============================================================
   ANIMATIONS
   ============================================================= */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(14px); }
  to   { opacity: 1; transform: translateY(0); }
}
section { animation: fadeUp 0.45s ease both; }
#news        { animation-delay: 0.05s; }
#publications{ animation-delay: 0.10s; }
#service     { animation-delay: 0.13s; }
#contact     { animation-delay: 0.15s; }

/* =============================================================
   RESPONSIVE
   ============================================================= */
@media (max-width: 680px) {
  .about-grid { grid-template-columns: 1fr; gap: 20px; }
  .about-photo { width: 140px; height: 140px; }
  .about-photo-wrap .social-links { flex-direction: row; width: auto; }
  .about-photo-wrap .social-link { justify-content: flex-start; font-size: 0.82rem; padding: 6px 12px; }
  .contact-grid { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .nav-hamburger { display: block; }
  .section-header h2 { font-size: 1.5rem; }
  .paper-top-row { flex-direction: column; align-items: flex-start; }
  main { padding-top: calc(var(--nav-h) + 16px); }
}