/* ============================================
   NAGPAL LAB — Site Stylesheet
   ============================================ */

:root {
  --color-bg: #fafaf8;
  --color-surface: #ffffff;
  --color-text: #1a1a1a;
  --color-text-muted: #5a5a5a;
  --color-accent: #1a5276;
  --color-accent-light: #2980b9;
  --color-accent-warm: #c0392b;
  --color-border: #e0ddd8;
  --color-highlight: #f0ece4;
  --font-heading: 'Playfair Display', Georgia, serif;
  --font-body: 'Source Sans 3', 'Segoe UI', sans-serif;
  --max-width: 960px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  font-size: 18px;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--color-accent-light); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--color-accent); }

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }

/* ---- HEADER ---- */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.site-logo { text-decoration: none; display: flex; flex-direction: column; gap: 0; }
.logo-text {
  font-family: var(--font-heading);
  font-size: 1.45rem;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1.2;
}
.logo-sub {
  font-size: 0.78rem;
  color: var(--color-text-muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.site-nav { display: flex; gap: 6px; }
.nav-link {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-text-muted);
  padding: 6px 12px;
  border-radius: 6px;
  transition: all 0.2s;
}
.nav-link:hover, .nav-link.active {
  color: var(--color-accent);
  background: var(--color-highlight);
}

.menu-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.menu-toggle span {
  display: block; width: 22px; height: 2px; background: var(--color-text);
  margin: 5px 0; transition: 0.3s;
}
.menu-toggle.open span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.menu-toggle.open span:nth-child(2) { opacity: 0; }
.menu-toggle.open span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* ---- HERO ---- */
.hero {
  background: linear-gradient(135deg, #1a5276 0%, #2c3e50 50%, #1a5276 100%);
  color: #fff;
  padding: 80px 0 72px;
}

.hero-inner { display: flex; align-items: center; gap: 48px; }

.hero-text { flex: 1; }
.hero-text h1 {
  font-family: var(--font-heading);
  font-size: 2.8rem;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 12px;
}
.hero-text .hero-tagline {
  font-size: 1.25rem;
  font-weight: 300;
  opacity: 0.9;
  margin-bottom: 20px;
  line-height: 1.6;
}
.hero-text .hero-affiliation {
  font-size: 1rem;
  opacity: 0.7;
  letter-spacing: 0.03em;
}

.hero-photo {
  width: 200px;
  height: 200px;
  border-radius: 50%;
  object-fit: cover;
  border: 4px solid rgba(255,255,255,0.25);
  flex-shrink: 0;
}

.hero-logos {
  margin-top: 24px;
}
.hero-logos img {
  height: 55px;
  width: auto;
  opacity: 0.9;
}

/* ---- HOMEPAGE SECTIONS ---- */
.home-section {
  padding: 56px 0;
}
.home-section:nth-child(even) { background: var(--color-surface); }

.section-title {
  font-family: var(--font-heading);
  font-size: 1.75rem;
  font-weight: 500;
  color: var(--color-accent);
  margin-bottom: 24px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-border);
}

.research-areas {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.research-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 28px 24px;
  overflow: hidden;
  transition: box-shadow 0.25s, transform 0.2s;
  text-decoration: none;
  display: block;
  color: inherit;
}
.research-card:hover {
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
  transform: translateY(-2px);
  color: inherit;
}
.research-card h3 {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  color: var(--color-accent);
  margin-bottom: 10px;
}
.research-card p { font-size: 0.95rem; color: var(--color-text-muted); line-height: 1.6; }

/* News list on homepage */
.news-list { list-style: none; }
.news-list li {
  padding: 14px 0;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  gap: 16px;
  align-items: baseline;
  font-size: 1rem;
}
.news-list li:last-child { border-bottom: none; }
.news-date {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  min-width: 100px;
  flex-shrink: 0;
}

.more-link {
  display: inline-block;
  margin-top: 20px;
  font-weight: 600;
  font-size: 1rem;
  color: var(--color-accent-light);
}
.more-link::after { content: ' →'; }

/* ---- PAGE CONTENT ---- */
.page-content { padding: 56px 0 72px; }

.page-title {
  font-family: var(--font-heading);
  font-size: 2.2rem;
  font-weight: 500;
  color: var(--color-accent);
  margin-bottom: 32px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-border);
}

/* ---- RESEARCH PAGE ---- */
.research-block { margin-bottom: 48px; scroll-margin-top: 80px; }
.research-block h2 {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  color: var(--color-accent);
  margin-bottom: 14px;
}
.research-block p { margin-bottom: 14px; }

.research-block-content {
  display: flex;
  gap: 28px;
  align-items: flex-start;
}
.research-block-img {
  width: 300px;
  flex-shrink: 0;
  border-radius: 8px;
  border: 1px solid var(--color-border);
  object-fit: contain;
  background: #fff;
}

.key-pubs { margin-top: 12px; padding-left: 20px; }
.key-pubs li {
  font-size: 0.95rem;
  color: var(--color-text-muted);
  margin-bottom: 6px;
}

/* ---- PUBLICATIONS PAGE ---- */
.pub-year {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  color: var(--color-accent);
  margin-top: 36px;
  margin-bottom: 14px;
  padding-bottom: 4px;
  border-bottom: 1px solid var(--color-border);
}
.pub-list { list-style: none; }
.pub-list li {
  padding: 12px 0;
  border-bottom: 1px solid #f0ece4;
  font-size: 1rem;
  line-height: 1.6;
}
.pub-list li:last-child { border-bottom: none; }
.pub-title { font-weight: 600; color: #3a3a3a; }
.pub-journal { font-weight: 600; font-style: italic; color: var(--color-accent-light); }
.pub-note { font-size: 0.9rem; color: var(--color-text-muted); }

/* ---- PEOPLE PAGE ---- */
.people-section { margin-bottom: 36px; }
.people-section h2 {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  color: var(--color-accent);
  margin-bottom: 16px;
}

.people-row-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 24px;
  justify-items: start;
}
.person-compact {
  text-align: center;
  max-width: 200px;
}
.person-photo-sm {
  width: 110px;
  height: 110px;
  border-radius: 50%;
  object-fit: cover;
  background: var(--color-highlight);
  border: 3px solid var(--color-border);
  margin: 0 auto 10px;
  display: block;
}
.person-name {
  font-weight: 600;
  font-size: 1.02rem;
  color: var(--color-text);
}
.person-role {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-top: 2px;
  line-height: 1.4;
}
.person-links {
  font-size: 0.85rem;
  margin-top: 6px;
}

/* ---- TEACHING ---- */
.course-item { margin-bottom: 28px; }
.course-item h3 {
  font-size: 1.15rem;
  color: var(--color-accent);
  margin-bottom: 4px;
}
.course-item .course-meta {
  font-size: 0.93rem;
  color: var(--color-text-muted);
  margin-bottom: 6px;
}

/* ---- NEWS PAGE ---- */
.news-full-list li {
  padding: 18px 0;
  border-bottom: 1px solid var(--color-border);
}
.news-full-list li:last-child { border-bottom: none; }

/* ---- JOIN US ---- */
.positions-list { margin-top: 20px; }
.position-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 24px;
  margin-bottom: 20px;
}
.position-card h3 {
  color: var(--color-accent);
  margin-bottom: 8px;
  font-size: 1.15rem;
}

/* ---- CONTACT ---- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 36px;
  margin-top: 20px;
}
.contact-block h3 {
  font-size: 1.1rem;
  color: var(--color-accent);
  margin-bottom: 10px;
}

/* ---- PI PAGE ---- */
.pi-header {
  display: flex;
  gap: 36px;
  align-items: flex-start;
  margin-bottom: 36px;
}
.pi-photo {
  width: 200px;
  height: 200px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--color-border);
  flex-shrink: 0;
}
.pi-intro h2 {
  font-family: var(--font-heading);
  font-size: 1.6rem;
  color: var(--color-accent);
  margin-bottom: 4px;
}
.pi-role {
  font-size: 1rem;
  color: var(--color-text-muted);
  margin-bottom: 10px;
}
.pi-links {
  font-size: 0.95rem;
}
.pi-section {
  margin-bottom: 36px;
}
.pi-section h2 {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  color: var(--color-accent);
  margin-bottom: 16px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--color-border);
}
.pi-section p {
  margin-bottom: 12px;
}
.pi-timeline {
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.pi-timeline-item {
  display: flex;
  gap: 24px;
  align-items: baseline;
}
.pi-year {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  min-width: 120px;
  flex-shrink: 0;
}
.pi-position {
  font-weight: 600;
  margin-bottom: 2px;
}
.pi-institution {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  margin-bottom: 2px;
}
.pi-thesis {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin-top: 4px;
}

/* ---- FOOTER ---- */
.site-footer {
  background: #1e2a33;
  color: rgba(255,255,255,0.7);
  padding: 44px 0;
  font-size: 0.95rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 32px;
  align-items: start;
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.footer-col a { color: rgba(255,255,255,0.6); }
.footer-col a:hover { color: #fff; }

.footer-title {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  color: #fff;
  margin-bottom: 4px;
}

.footer-col-logo {
  gap: 12px;
}
.footer-copy { color: rgba(255,255,255,0.35); font-size: 0.85rem; }
.footer-logo {
  width: 100%;
  max-width: 280px;
  height: auto;
  opacity: 0.85;
  border-radius: 4px;
}

/* ---- RESPONSIVE ---- */
@media (max-width: 768px) {
  .menu-toggle { display: block; }

  .site-nav {
    display: none;
    position: absolute;
    top: 68px; left: 0; right: 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    padding: 12px 24px;
  }
  .site-nav.open { display: flex; }

  .hero { padding: 48px 0 40px; }
  .hero-inner { flex-direction: column-reverse; text-align: center; gap: 24px; }
  .hero-text h1 { font-size: 2rem; }
  .hero-photo { width: 150px; height: 150px; }

  .contact-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }

  .pi-header { flex-direction: column; align-items: center; text-align: center; }
  .pi-photo { width: 160px; height: 160px; }
  .pi-timeline-item { flex-direction: column; gap: 4px; }

  .research-areas { grid-template-columns: 1fr; }
  .research-block-content { flex-direction: column; }
  .research-block-img { width: 100%; max-width: 320px; }

  .people-row-grid { grid-template-columns: repeat(2, 1fr); }
}