:root {
  --navy: #003865;
  --blue-accent: #0068a5;
  --red: #c41230;
  --white: #ffffff;
  --off-white: #f7f7f5;
  --light-gray: #ebebeb;
  --mid-gray: #767676;
  --text: #1a1a1a;
  --border: #d0d0d0;
  --ink: #111827;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  background: var(--white);
  color: var(--text);
  font-family: 'Source Sans 3', sans-serif;
  font-weight: 300;
  line-height: 1.6;
  font-size: 16px;
}

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

/* TOP BAR */
.topbar {
  background: var(--navy);
  color: rgba(255,255,255,0.65);
  font-size: 0.72rem;
  letter-spacing: 0.05em;
  padding: 0.4rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.topbar a { color: rgba(255,255,255,0.65); font-size: 0.72rem; }
.topbar a:hover { color: white; text-decoration: none; }

/* HEADER */
header {
  background: var(--white);
  border-bottom: 3px solid var(--navy);
  padding: 1.25rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0,0,0,0.07);
}

.logo-block { display: flex; align-items: center; gap: 1rem; text-decoration: none; }
.logo-block:hover { text-decoration: none; }
.logo-bar { width: 4px; height: 44px; background: var(--red); flex-shrink: 0; }
.logo-name {
  font-family: 'Source Serif 4', Georgia, serif;
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--navy);
  line-height: 1.2;
  display: block;
}
.logo-title {
  font-size: 0.72rem;
  color: var(--mid-gray);
  font-weight: 400;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  display: block;
}

nav { display: flex; align-items: center; gap: 0; }
nav a {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--navy);
  padding: 0.5rem 0.85rem;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  transition: background 0.15s;
  border-bottom: 2px solid transparent;
}
nav a:hover { background: var(--off-white); text-decoration: none; }
nav a.active { border-bottom-color: var(--red); color: var(--red); }

/* PAGE HERO */
.page-hero {
  background: var(--navy);
  color: white;
  padding: 3.5rem 2rem 3rem;
}
.page-hero-inner { max-width: 1100px; margin: 0 auto; }
.page-hero-label {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.5);
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.page-hero-label::before {
  content: '';
  display: inline-block;
  width: 24px; height: 2px;
  background: var(--red);
}
.page-hero h1 {
  font-family: 'Source Serif 4', Georgia, serif;
  font-size: clamp(1.8rem, 4vw, 3rem);
  font-weight: 300;
  line-height: 1.15;
  max-width: 680px;
}
.page-hero h1 em { font-style: italic; color: rgba(255,255,255,0.7); }
.page-hero-sub {
  font-size: 1rem;
  color: rgba(255,255,255,0.7);
  max-width: 560px;
  margin-top: 1rem;
  line-height: 1.7;
}

/* LAYOUT */
.page-inner { max-width: 1100px; margin: 0 auto; padding: 0 2rem; }
.content-grid {
  display: grid;
  grid-template-columns: 1fr 290px;
  gap: 3rem;
  padding: 3rem 0;
}

/* SECTION HEADERS */
.section-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.75rem;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--navy);
}
.section-header h2 {
  font-family: 'Source Serif 4', Georgia, serif;
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--navy);
  white-space: nowrap;
}
.section-header-rule { flex: 1; height: 1px; background: var(--border); }

/* RESEARCH CARDS */
.research-card {
  display: flex;
  gap: 1.25rem;
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--light-gray);
}
.research-card:first-of-type { padding-top: 0; }

.card-type-bar {
  width: 3px;
  flex-shrink: 0;
  align-self: stretch;
  background: var(--border);
}
.card-type-bar.quantum { background: var(--navy); }
.card-type-bar.ai { background: var(--blue-accent); }
.card-type-bar.linguistics { background: #7b4f9e; }
.card-type-bar.biology { background: #2e7d32; }
.card-type-bar.business { background: var(--red); }
.card-type-bar.community { background: #c47d00; }

.card-body { flex: 1; }
.card-topic {
  font-size: 0.67rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--blue-accent);
  margin-bottom: 0.35rem;
}
.card-title {
  font-family: 'Source Serif 4', Georgia, serif;
  font-size: 1.08rem;
  font-weight: 600;
  color: var(--navy);
  line-height: 1.35;
  margin-bottom: 0.5rem;
}
.card-desc { font-size: 0.88rem; color: #555; line-height: 1.65; }
.card-meta { margin-top: 0.75rem; display: flex; gap: 0.75rem; align-items: center; flex-wrap: wrap; }

.card-status {
  font-size: 0.63rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.2rem 0.55rem;
  border: 1px solid;
}
.status-active { color: #1b6b2a; border-color: #1b6b2a; background: #f0faf1; }
.status-planned { color: var(--mid-gray); border-color: var(--border); }
.status-research { color: #7b4f9e; border-color: #7b4f9e; background: #faf5ff; }
.status-review { color: var(--blue-accent); border-color: var(--blue-accent); background: #f0f7ff; }

/* PUBLICATION ITEMS */
.pub-item {
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--light-gray);
  display: flex;
  gap: 1.25rem;
}
.pub-item:first-of-type { padding-top: 0; }
.pub-year {
  font-family: 'Source Serif 4', serif;
  font-size: 0.9rem;
  color: var(--mid-gray);
  font-weight: 300;
  min-width: 44px;
  padding-top: 0.1rem;
}
.pub-body { flex: 1; }
.pub-venue {
  font-size: 0.67rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--red);
  margin-bottom: 0.25rem;
}
.pub-title {
  font-family: 'Source Serif 4', Georgia, serif;
  font-size: 1rem;
  font-weight: 600;
  color: var(--navy);
  line-height: 1.4;
  margin-bottom: 0.3rem;
}
.pub-title a { color: var(--navy); }
.pub-title a:hover { color: var(--blue-accent); }
.pub-desc { font-size: 0.83rem; color: #666; line-height: 1.55; }

/* TABS */
.tab-bar {
  display: flex;
  border-bottom: 2px solid var(--border);
  margin-bottom: 0;
  overflow-x: auto;
}
.tab {
  font-size: 0.77rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 0.75rem 1.1rem;
  color: var(--mid-gray);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  white-space: nowrap;
  transition: all 0.15s;
  user-select: none;
}
.tab:hover { color: var(--navy); }
.tab.active { color: var(--navy); border-bottom-color: var(--red); }
.tab-panel { display: none; padding-top: 1.75rem; }
.tab-panel.active { display: block; }

/* ABOUT BANNER */
.about-banner {
  background: var(--navy);
  color: white;
  padding: 2.5rem;
  margin-bottom: 2.5rem;
}
.about-banner p {
  font-family: 'Source Serif 4', serif;
  font-size: clamp(1.05rem, 2vw, 1.3rem);
  font-weight: 300;
  line-height: 1.75;
  color: rgba(255,255,255,0.88);
}
.about-banner p em { font-style: italic; color: white; }
.about-banner p strong { font-weight: 600; color: white; }

/* SIDEBAR */
.sidebar { position: relative; }
.sidebar-sticky { position: sticky; top: 90px; display: flex; flex-direction: column; gap: 1.5rem; }

.sidebar-block {
  background: var(--off-white);
  border-top: 3px solid var(--navy);
  padding: 1.5rem;
}
.sidebar-block h3 {
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--navy);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 1rem;
}
.bio-text { font-size: 0.85rem; color: #444; line-height: 1.65; margin-bottom: 0.65rem; }

.contact-list { list-style: none; }
.contact-list li {
  font-size: 0.82rem;
  padding: 0.4rem 0;
  border-bottom: 1px solid var(--border);
  color: #444;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.5rem;
}
.contact-list li:last-child { border-bottom: none; }
.contact-list a { color: var(--blue-accent); font-size: 0.82rem; }
.contact-list .label { color: var(--mid-gray); font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.06em; flex-shrink: 0; }

.expertise-tags { display: flex; flex-wrap: wrap; gap: 0.4rem; }
.exp-tag { font-size: 0.7rem; padding: 0.25rem 0.6rem; background: white; border: 1px solid var(--border); color: #444; }

/* TIMELINE */
.tl-item {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: 1.5rem;
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--light-gray);
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}
.tl-item:first-child { padding-top: 0; }
.tl-item.visible { opacity: 1; transform: translateY(0); }
.tl-year { font-family: 'Source Serif 4', serif; font-size: 0.82rem; color: var(--mid-gray); line-height: 1.4; }
.tl-title { font-family: 'Source Serif 4', serif; font-size: 1rem; font-weight: 600; color: var(--navy); line-height: 1.3; margin-bottom: 0.35rem; }
.tl-desc { font-size: 0.85rem; color: #555; line-height: 1.6; }

/* NAV CARDS (for homepage featured links) */
.nav-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1px; background: var(--light-gray); margin-top: 2rem; }
.nav-card {
  background: white;
  padding: 1.75rem;
  text-decoration: none;
  display: block;
  border-top: 3px solid transparent;
  transition: border-color 0.2s, background 0.2s;
}
.nav-card:hover { border-top-color: var(--red); background: var(--off-white); text-decoration: none; }
.nav-card-label { font-size: 0.65rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.12em; color: var(--mid-gray); margin-bottom: 0.5rem; }
.nav-card-title { font-family: 'Source Serif 4', serif; font-size: 1.05rem; font-weight: 600; color: var(--navy); line-height: 1.3; margin-bottom: 0.4rem; }
.nav-card-desc { font-size: 0.82rem; color: #666; line-height: 1.55; }
.nav-card-arrow { font-size: 0.75rem; color: var(--red); margin-top: 0.75rem; display: block; font-weight: 600; letter-spacing: 0.05em; }

/* STATS ROW */
.stats-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  background: var(--light-gray);
  margin: 2rem 0;
}
.stat-box {
  background: white;
  flex: 1;
  min-width: 120px;
  padding: 1.5rem;
  text-align: center;
  border-right: 1px solid var(--light-gray);
}
.stat-box:last-child { border-right: none; }
.stat-num {
  font-family: 'Source Serif 4', serif;
  font-size: 2.2rem;
  font-weight: 300;
  color: var(--navy);
  line-height: 1;
  display: block;
}
.stat-label { font-size: 0.7rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--mid-gray); margin-top: 0.3rem; display: block; }

/* FOOTER */
footer { background: var(--navy); color: rgba(255,255,255,0.55); padding: 2.5rem 2rem; margin-top: 4rem; }
.footer-inner { max-width: 1100px; margin: 0 auto; display: flex; justify-content: space-between; align-items: flex-start; flex-wrap: wrap; gap: 2rem; }
.footer-name { font-family: 'Source Serif 4', serif; font-size: 1.1rem; color: white; margin-bottom: 0.3rem; }
.footer-tagline { font-size: 0.8rem; }
.footer-links { display: flex; flex-direction: column; gap: 0.4rem; }
.footer-links a { color: rgba(255,255,255,0.55); font-size: 0.8rem; }
.footer-links a:hover { color: white; text-decoration: none; }
.footer-copy { font-size: 0.7rem; color: rgba(255,255,255,0.3); margin-top: 0.5rem; }

@media (max-width: 768px) {
  .content-grid { grid-template-columns: 1fr; }
  .sidebar-sticky { position: static; }
  nav a { padding: 0.5rem 0.5rem; font-size: 0.75rem; }
}
@media (max-width: 520px) {
  nav { display: none; }
}