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

:root {
  --navy:       #1e3a5f;
  --navy-dark:  #0f2340;
  --teal:       #0d9488;
  --teal-light: #14b8a6;
  --text:       #1f2937;
  --text-muted: #6b7280;
  --bg:         #f8fafc;
  --bg-alt:     #f0f4f8;
  --white:      #ffffff;
  --border:     #e5e7eb;
  --shadow-sm:  0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.05);
  --shadow-md:  0 4px 12px rgba(0,0,0,.10), 0 2px 4px rgba(0,0,0,.06);
  --shadow-lg:  0 10px 30px rgba(0,0,0,.12), 0 4px 8px rgba(0,0,0,.06);
  --radius:     10px;
  --radius-sm:  6px;
  --font-sans:  'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-serif: 'DM Serif Display', Georgia, serif;
  --transition: 0.22s ease;
}

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

body {
  font-family: var(--font-sans);
  color: var(--text);
  background: var(--white);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* ── Layout ────────────────────────────────────────────────────────────────── */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section { padding: 5rem 0; }
.section-alt { background: var(--bg-alt); }

.section-title {
  font-family: var(--font-serif);
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  color: var(--navy);
  margin-bottom: 0.5rem;
  position: relative;
}

.section-title::after {
  content: '';
  display: block;
  width: 48px;
  height: 3px;
  background: var(--teal);
  border-radius: 2px;
  margin-top: 0.5rem;
}

.section-subtitle {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-bottom: 2.5rem;
  margin-top: 0.5rem;
}

/* ── Navigation ────────────────────────────────────────────────────────────── */
#navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  transition: box-shadow var(--transition);
}

#navbar.scrolled { box-shadow: var(--shadow-sm); }

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--navy);
  letter-spacing: -0.02em;
}

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

.nav-links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: color var(--transition);
}

.nav-links a:hover { color: var(--navy); }

.nav-links .btn-nav {
  background: var(--navy);
  color: var(--white) !important;
  padding: 0.45rem 1.1rem;
  border-radius: 20px;
  font-size: 0.88rem;
  transition: background var(--transition);
}

.nav-links .btn-nav:hover { background: var(--teal); }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.4rem;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--navy);
  border-radius: 2px;
  transition: var(--transition);
}

/* ── Hero ───────────────────────────────────────────────────────────────────── */
.hero {
  min-height: 100vh;
  padding-top: 64px;
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, var(--navy-dark) 0%, var(--navy) 60%, #1e4a7f 100%);
  overflow: hidden;
  position: relative;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Ccircle cx='30' cy='30' r='2'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero .container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 4rem 1.5rem;
}

.hero-content,
.hero-image {
  position: relative;
  z-index: 1;
}

/* Two-column hero layout */
.hero {
  display: grid;
  grid-template-columns: 1fr;
}

.hero > * {
  max-width: 1100px;
  margin: 0 auto;
  width: 100%;
  padding: 5rem 1.5rem 4rem;
}

/* Mobile: photo shown centred above the text */
.hero-image {
  display: flex;
  justify-content: center;
  align-items: center;
  order: -1;               /* renders before .hero-content in the grid */
  padding: 3rem 1.5rem 0;  /* overrides the generic .hero > * padding */
}

.hero-image img {
  width: 140px;
  height: 140px;
  object-fit: cover;
  border-radius: 50%;
  border: 3px solid rgba(255,255,255,0.28);
  box-shadow: 0 8px 28px rgba(0,0,0,0.35);
}

/* Pull the text up since the photo sits above it on mobile */
.hero-content {
  padding-top: 1.6rem;
}

/* Desktop (≥900px): side-by-side, photo on the right */
@media (min-width: 900px) {
  .hero {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0;
  }
  .hero-content {
    flex: 1;
    max-width: 600px;
    padding: 5rem 2rem 4rem 1.5rem;
    margin: 0 auto 0 max(1.5rem, calc((100vw - 1100px) / 2));
  }
  .hero-image {
    order: 0;              /* restore natural source order (right side) */
    flex: 0 0 320px;
    padding: 4rem 1.5rem 4rem 0;
    margin: 0;
  }
  .hero-image img {
    width: 280px;
    height: 280px;
    border: 4px solid rgba(255,255,255,0.2);
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
  }
}

.hero-eyebrow {
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--teal-light);
  margin-bottom: 1rem;
}

.hero-title {
  font-family: var(--font-serif);
  font-size: clamp(2.4rem, 5vw, 3.6rem);
  color: var(--white);
  line-height: 1.1;
  margin-bottom: 1.3rem;
}

.hero-title .accent { color: var(--white); }

.hero-bio {
  font-size: 1.05rem;
  color: rgba(255,255,255,0.82);
  line-height: 1.7;
  max-width: 520px;
  margin-bottom: 1.4rem;
}

.hero-bio strong { color: var(--white); }

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 2rem;
}

.tag {
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.2);
  color: rgba(255,255,255,0.88);
  font-size: 0.78rem;
  font-weight: 500;
  padding: 0.3rem 0.75rem;
  border-radius: 20px;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.btn-primary {
  background: var(--teal);
  color: var(--white);
  font-weight: 600;
  font-size: 0.92rem;
  padding: 0.7rem 1.5rem;
  border-radius: 8px;
  transition: background var(--transition), transform var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.btn-primary:hover {
  background: var(--teal-light);
  transform: translateY(-1px);
}

.btn-secondary {
  background: rgba(255,255,255,0.1);
  color: var(--white);
  font-weight: 500;
  font-size: 0.92rem;
  padding: 0.7rem 1.3rem;
  border-radius: 8px;
  border: 1px solid rgba(255,255,255,0.25);
  transition: background var(--transition), transform var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}

.btn-secondary:hover {
  background: rgba(255,255,255,0.18);
  transform: translateY(-1px);
}

/* ── About ──────────────────────────────────────────────────────────────────── */
.about-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
  margin-top: 2.5rem;
}

@media (min-width: 800px) {
  .about-grid { grid-template-columns: 1.4fr 1fr; gap: 4rem; }
}

.about-text p {
  color: var(--text);
  font-size: 0.97rem;
  line-height: 1.75;
  margin-bottom: 1rem;
}

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

.skills-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1.3rem;
}

.skill-chip {
  background: var(--white);
  border: 1px solid var(--border);
  color: var(--navy);
  font-size: 0.78rem;
  font-weight: 500;
  padding: 0.3rem 0.8rem;
  border-radius: 20px;
}

.about-cards { display: flex; flex-direction: column; gap: 0.85rem; }

.info-card {
  display: flex;
  align-items: flex-start;
  gap: 0.85rem;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.9rem 1rem;
  transition: box-shadow var(--transition);
}

.info-card:hover { box-shadow: var(--shadow-sm); }

.info-icon { font-size: 1.3rem; flex-shrink: 0; margin-top: 0.1rem; }

.info-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--teal);
  margin-bottom: 0.15rem;
}

.info-value {
  font-size: 0.88rem;
  color: var(--text);
  line-height: 1.4;
}

.info-cert-list {
  list-style: disc;
  margin: 0.2rem 0 0 1.1rem;
  padding: 0;
  font-size: 0.88rem;
  color: var(--text);
  line-height: 1.65;
}

/* ── Featured Project ────────────────────────────────────────────────────────── */
.featured-project {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2.5rem;
  margin-bottom: 2.5rem;
  position: relative;
  box-shadow: var(--shadow-md);
  border-top: 4px solid var(--teal);
  margin-top: 2rem;
}

.featured-badge {
  position: absolute;
  top: -1px;
  right: 2rem;
  background: var(--teal);
  color: var(--white);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.3rem 0.8rem;
  border-radius: 0 0 6px 6px;
}

.project-tags-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1rem;
}

.tag-tech {
  background: #eff6ff;
  color: #1d4ed8;
  font-size: 0.72rem;
  font-weight: 600;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  letter-spacing: 0.02em;
}

.featured-title {
  font-family: var(--font-serif);
  font-size: clamp(1.4rem, 2.5vw, 1.9rem);
  color: var(--navy);
  margin-bottom: 0.9rem;
  line-height: 1.25;
}

.featured-desc {
  font-size: 0.97rem;
  color: var(--text);
  line-height: 1.7;
  margin-bottom: 1.5rem;
  max-width: 680px;
}

.results-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-bottom: 1.5rem;
}

@media (min-width: 600px) {
  .results-grid { grid-template-columns: repeat(4, 1fr); }
}

.result-item {
  background: var(--bg-alt);
  border-radius: var(--radius-sm);
  padding: 1rem;
  text-align: center;
}

.result-number {
  font-size: 1.7rem;
  font-weight: 700;
  color: var(--navy);
  line-height: 1;
  margin-bottom: 0.35rem;
}

.result-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  line-height: 1.3;
}

.result-label span { display: block; font-size: 0.7rem; margin-top: 0.1rem; }

.featured-bullets {
  list-style: none;
  margin-bottom: 1.8rem;
}

.featured-bullets li {
  padding: 0.35rem 0 0.35rem 1.4rem;
  position: relative;
  font-size: 0.93rem;
  color: var(--text);
  line-height: 1.5;
}

.featured-bullets li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--teal);
  font-size: 0.85rem;
}

.featured-links { display: flex; gap: 0.75rem; flex-wrap: wrap; align-items: center; }

.btn-demo {
  background: transparent;
  color: var(--teal);
  font-weight: 600;
  font-size: 0.92rem;
  padding: 0.65rem 1.4rem;
  border-radius: 8px;
  border: 2px solid var(--teal);
  transition: background var(--transition), color var(--transition), transform var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}
.btn-demo:hover {
  background: var(--teal);
  color: var(--white);
  transform: translateY(-1px);
}

/* ── Project Cards ─────────────────────────────────────────────────────────── */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1.3rem;
}

.project-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.4rem;
  display: flex;
  flex-direction: column;
  transition: box-shadow var(--transition), transform var(--transition);
}

.project-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.project-card-coming-soon {
  opacity: 0.7;
  border-style: dashed;
}

.project-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.9rem;
}

.project-icon { font-size: 1.8rem; }

.project-card-tags { display: flex; gap: 0.35rem; flex-wrap: wrap; }

.coming-soon-tag {
  background: #f3f4f6;
  color: var(--text-muted) !important;
}

.project-card h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 0.5rem;
  line-height: 1.3;
}

.project-card p {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.6;
  flex: 1;
}

.project-card-footer { margin-top: 1.2rem; }

.card-link {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--teal);
  transition: color var(--transition);
}

.card-link:hover { color: var(--navy); }

/* ── Publications ──────────────────────────────────────────────────────────── */
.publication-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-left: 4px solid var(--teal);
  border-radius: var(--radius);
  padding: 1.8rem 2rem;
  display: grid;
  grid-template-columns: 60px 1fr;
  gap: 1.5rem;
  box-shadow: var(--shadow-sm);
  margin-top: 2rem;
}

.pub-year {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--teal);
  padding-top: 0.1rem;
}

.pub-type {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--teal);
  margin-bottom: 0.5rem;
}

.pub-title {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--navy);
  line-height: 1.35;
  margin-bottom: 0.4rem;
}

.pub-authors { font-size: 0.88rem; color: var(--text); font-weight: 500; margin-bottom: 0.2rem; }

.pub-journal { font-size: 0.88rem; color: var(--text-muted); margin-bottom: 0.7rem; }

.pub-abstract {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 1rem;
}

.pub-links { display: flex; flex-wrap: wrap; gap: 0.7rem; }

.pub-link {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--teal);
  background: #f0fdfa;
  border: 1px solid #99f6e4;
  border-radius: 4px;
  padding: 0.25rem 0.7rem;
  transition: background var(--transition);
}

.pub-link:hover { background: #ccfbf1; color: var(--navy); }

/* ── Academic Service ────────────────────────────────────────────────────────── */
.service-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.3rem;
  margin-top: 2rem;
}

@media (min-width: 600px) { .service-grid { grid-template-columns: 1fr 1fr; } }

.service-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.6rem;
  transition: box-shadow var(--transition);
}

.service-card:hover { box-shadow: var(--shadow-md); }

.service-icon { font-size: 1.8rem; margin-bottom: 0.8rem; }

.service-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 0.2rem;
}

.service-journal {
  font-size: 0.88rem;
  font-style: italic;
  color: var(--teal);
  margin-bottom: 0.3rem;
}

.service-date {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 0.8rem;
}

.service-desc {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ── Contact ────────────────────────────────────────────────────────────────── */
.contact-container { text-align: center; }

.contact-desc {
  max-width: 560px;
  margin: 1rem auto 2.5rem;
  color: var(--text-muted);
  font-size: 1rem;
  line-height: 1.7;
}

.contact-links {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1.2rem;
  max-width: 800px;
  margin: 0 auto;
}

.contact-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.6rem 1rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
  cursor: pointer;
}

.contact-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-3px);
  border-color: var(--teal-light);
}

.contact-icon { font-size: 1.8rem; color: var(--teal); }
.contact-label { font-size: 0.75rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; color: var(--text-muted); }
.contact-value { font-size: 0.85rem; font-weight: 500; color: var(--navy); }

/* ── Footer ─────────────────────────────────────────────────────────────────── */
.footer {
  background: var(--navy-dark);
  color: rgba(255,255,255,0.55);
  text-align: center;
  padding: 2rem 1.5rem;
  font-size: 0.85rem;
}

.footer p + p { margin-top: 0.35rem; }
.footer-sub { font-size: 0.78rem; opacity: 0.6; }

/* ── Animations ─────────────────────────────────────────────────────────────── */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ── Mobile ─────────────────────────────────────────────────────────────────── */
@media (max-width: 700px) {
  .nav-toggle { display: flex; }

  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0; right: 0;
    background: var(--white);
    flex-direction: column;
    padding: 1rem 1.5rem 1.5rem;
    border-bottom: 1px solid var(--border);
    gap: 0.3rem;
    box-shadow: var(--shadow-md);
  }

  .nav-links.open { display: flex; }

  .nav-links li { width: 100%; }
  .nav-links a { display: block; padding: 0.6rem 0; font-size: 1rem; }
  .nav-links .btn-nav { text-align: center; border-radius: 6px; padding: 0.6rem; }

  .publication-card { grid-template-columns: 1fr; gap: 0.5rem; }
  .pub-year { font-size: 1rem; }

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

  .featured-project { padding: 1.5rem; }
}


@media (max-width: 480px) {
  .hero-title { font-size: 2.1rem; }
  .contact-links { grid-template-columns: 1fr 1fr; }
}