:root {
  --bg: #05070f;
  --bg-2: #0a0e1c;
  --surface: rgba(255, 255, 255, 0.04);
  --surface-strong: rgba(255, 255, 255, 0.07);
  --text: #eef2ff;
  --muted: #9aa6c4;
  --muted-dim: #6b7596;
  --primary: #5b8cff;
  --primary-2: #8b5cf6;
  --accent: #22d3ee;
  --brand: #10b981;
  --brand-2: #059669;
  --brand-glow: rgba(16, 185, 129, 0.38);
  --border: rgba(255, 255, 255, 0.1);
  --border-soft: rgba(255, 255, 255, 0.06);
  --glow: 0 0 0 1px rgba(255, 255, 255, 0.05), 0 24px 60px rgba(2, 6, 23, 0.6);
  --radius: 20px;
  --container: 1140px;
  --nav-bg: rgba(7, 11, 24, 0.97);
  --orb-opacity: 0.55;
  --grid-line: rgba(255, 255, 255, 0.025);
  color-scheme: dark;
}

/* ---------- Light theme ---------- */
[data-theme='light'] {
  --bg: #f4f6fc;
  --bg-2: #ffffff;
  --surface: rgba(15, 23, 42, 0.03);
  --surface-strong: rgba(15, 23, 42, 0.06);
  --text: #0f172a;
  --muted: #51607d;
  --muted-dim: #8590ab;
  --primary: #3b6cf6;
  --primary-2: #7c3aed;
  --accent: #0e9aae;
  --border: rgba(15, 23, 42, 0.12);
  --border-soft: rgba(15, 23, 42, 0.07);
  --glow: 0 0 0 1px rgba(15, 23, 42, 0.04), 0 20px 50px rgba(15, 23, 42, 0.1);
  --nav-bg: rgba(255, 255, 255, 0.97);
  --orb-opacity: 0.22;
  --grid-line: rgba(15, 23, 42, 0.04);
  color-scheme: light;
}

[data-theme='light'] .bg-aurora {
  background:
    radial-gradient(1200px 600px at 80% -10%, rgba(91, 140, 255, 0.14), transparent 60%),
    linear-gradient(180deg, #eef2fb 0%, #f4f6fc 50%, #eef2fb 100%);
}
[data-theme='light'] .site-header {
  background: rgba(244, 246, 252, 0.72);
}
[data-theme='light'] .hero-highlights li,
[data-theme='light'] .chip-list li,
[data-theme='light'] .profile-stat-grid div,
[data-theme='light'] .contact-form input,
[data-theme='light'] .contact-form textarea,
[data-theme='light'] .contact-socials a {
  background: rgba(15, 23, 42, 0.03);
}
[data-theme='light'] .quote-card::before {
  color: rgba(59, 108, 246, 0.16);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
}

h1, h2, h3 {
  font-family: 'Sora', 'Inter', sans-serif;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  z-index: 2000;
  background: var(--primary);
  color: #fff;
  padding: 10px 16px;
  border-radius: 0 0 10px 0;
}
.skip-link:focus {
  left: 0;
}

.container {
  width: min(100% - 48px, var(--container));
  margin: 0 auto;
}

.section {
  padding: 110px 0;
  position: relative;
}

/* ---------- Animated aurora background ---------- */
.bg-aurora {
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(1200px 600px at 80% -10%, rgba(91, 140, 255, 0.12), transparent 60%),
    linear-gradient(180deg, #05070f 0%, #070b18 50%, #05070f 100%);
  overflow: hidden;
}

.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: var(--orb-opacity);
  will-change: transform;
  transition: opacity 0.4s ease;
}
.orb-1 {
  width: 520px; height: 520px;
  background: radial-gradient(circle, rgba(91, 140, 255, 0.7), transparent 70%);
  top: -120px; left: -80px;
  animation: drift1 22s ease-in-out infinite;
}
.orb-2 {
  width: 460px; height: 460px;
  background: radial-gradient(circle, rgba(139, 92, 246, 0.6), transparent 70%);
  top: 30%; right: -120px;
  animation: drift2 26s ease-in-out infinite;
}
.orb-3 {
  width: 400px; height: 400px;
  background: radial-gradient(circle, rgba(34, 211, 238, 0.4), transparent 70%);
  bottom: -120px; left: 30%;
  animation: drift3 30s ease-in-out infinite;
}
.grid-overlay {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 30%, transparent 80%);
}

@keyframes drift1 { 50% { transform: translate(60px, 50px) scale(1.1); } }
@keyframes drift2 { 50% { transform: translate(-50px, 40px) scale(1.05); } }
@keyframes drift3 { 50% { transform: translate(40px, -40px) scale(1.12); } }

/* ---------- Glass ---------- */
.glass {
  background: var(--surface);
  border: 1px solid var(--border);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  box-shadow: var(--glow);
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(5, 7, 15, 0.6);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-soft);
}
.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 74px;
  gap: 20px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
}
.brand-mark {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  color: #fff;
  border-radius: 50%;
  font-size: 0.85rem;
  letter-spacing: 0.06em;
  box-shadow: 0 6px 20px var(--brand-glow);
  flex-shrink: 0;
}
.brand-text { font-size: 0.95rem; white-space: nowrap; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 22px;
}
.nav-links a {
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 500;
  transition: color 0.2s ease;
  position: relative;
}
.nav-links a:not(.nav-cta):hover,
.nav-links a.active:not(.nav-cta) {
  color: var(--text);
}
.nav-links a.nav-cta { color: #fff; }
.nav-links a:not(.nav-cta)::after {
  content: '';
  position: absolute;
  left: 0; bottom: -6px;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.25s ease;
}
.nav-links a.active:not(.nav-cta)::after { transform: scaleX(1); }

.nav-end {
  display: flex;
  align-items: center;
  gap: 10px;
}

.theme-toggle {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  cursor: pointer;
  transition: background 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}
.theme-toggle:hover {
  border-color: var(--primary);
  transform: translateY(-1px);
}
.theme-toggle svg { width: 18px; height: 18px; }
.theme-toggle .icon-sun { display: none; }
[data-theme='light'] .theme-toggle .icon-sun { display: block; }
[data-theme='light'] .theme-toggle .icon-moon { display: none; }

.nav-toggle {
  display: none;
  background: transparent;
  border: 0;
  cursor: pointer;
  padding: 6px;
}
.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  margin: 5px 0;
  transition: transform 0.3s ease, opacity 0.3s ease;
}
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 24px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  white-space: nowrap;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary {
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  color: #fff;
  box-shadow: 0 10px 30px var(--brand-glow);
}
.btn-primary:hover { box-shadow: 0 14px 40px rgba(16, 185, 129, 0.5); }
.btn-ghost {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-ghost:hover { background: var(--surface-strong); }

/* ---------- Hero ---------- */
.hero {
  padding: 120px 0 80px;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  align-items: center;
  gap: 56px;
}
.eyebrow,
.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  font-size: 0.74rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 18px;
}
.pulse-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 0 rgba(34, 211, 238, 0.6);
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(34, 211, 238, 0.6); }
  70% { box-shadow: 0 0 0 8px rgba(34, 211, 238, 0); }
  100% { box-shadow: 0 0 0 0 rgba(34, 211, 238, 0); }
}
.hero-copy h1 {
  font-size: clamp(2.6rem, 5vw, 4.4rem);
  margin-bottom: 22px;
  max-width: 16ch;
}
.grad-text {
  background: linear-gradient(120deg, var(--primary), var(--primary-2) 50%, var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-text {
  max-width: 56ch;
  color: var(--muted);
  font-size: 1.05rem;
}
.hero-actions {
  display: flex;
  gap: 14px;
  margin: 30px 0;
  flex-wrap: wrap;
}
.hero-highlights {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
}
.hero-highlights li {
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 9px 14px;
  border-radius: 999px;
  color: var(--muted);
  font-size: 0.86rem;
}

/* ---------- Profile card ---------- */
.hero-visual { display: flex; justify-content: center; }
.profile-card {
  width: min(460px, 100%);
  border-radius: 26px;
  padding: 32px;
  position: relative;
  text-align: center;
  overflow: hidden;
}
.profile-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% 0%, rgba(91, 140, 255, 0.18), transparent 60%);
  pointer-events: none;
}
.profile-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(34, 211, 238, 0.1);
  border: 1px solid rgba(34, 211, 238, 0.25);
  color: var(--accent);
  padding: 7px 14px;
  border-radius: 999px;
  font-size: 0.78rem;
  margin-bottom: 22px;
}
.profile-avatar {
  width: 132px;
  height: 132px;
  margin: 0 auto 18px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--primary), var(--primary-2));
  border-radius: 50%;
  font-family: 'Sora', sans-serif;
  font-size: 2.6rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  color: #fff;
  box-shadow: 0 0 40px rgba(91, 140, 255, 0.45);
  overflow: hidden;
  position: relative;
}
.profile-avatar img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 18%;
  border-radius: 50%;
}
.profile-name {
  font-family: 'Sora', sans-serif;
  font-weight: 700;
  font-size: 1.25rem;
}
.profile-role {
  color: var(--muted);
  font-size: 0.88rem;
  margin-bottom: 24px;
}
.profile-stat-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
.profile-stat-grid div {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-soft);
  border-radius: 14px;
  padding: 14px 10px;
}
.profile-stat-grid strong {
  display: block;
  font-family: 'Sora', sans-serif;
  font-size: 1.4rem;
  background: linear-gradient(120deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.profile-stat-grid span {
  display: block;
  font-size: 0.76rem;
  color: var(--muted);
  margin-top: 2px;
}

/* ---------- Trust bar ---------- */
.trust-bar {
  margin-top: 72px;
  display: flex;
  align-items: center;
  gap: 28px;
  flex-wrap: wrap;
  padding-top: 32px;
  border-top: 1px solid var(--border-soft);
}
.trust-label {
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 0.72rem;
  color: var(--muted-dim);
  font-weight: 600;
}
.trust-bar ul {
  display: flex;
  flex-wrap: wrap;
  gap: 28px;
  list-style: none;
}
.trust-bar li {
  color: var(--muted);
  font-weight: 600;
  font-size: 0.95rem;
  opacity: 0.8;
  transition: opacity 0.2s ease, color 0.2s ease;
}
.trust-bar li:hover { opacity: 1; color: var(--text); }

/* ---------- Headings ---------- */
.section-heading { margin-bottom: 52px; max-width: 720px; }
.about h2,
.section-heading h2,
.education h2,
.contact-panel h2 {
  font-size: clamp(2rem, 3.4vw, 2.9rem);
}
.section-sub,
.about-lead {
  color: var(--muted);
  margin-top: 16px;
  font-size: 1.02rem;
}

/* ---------- About ---------- */
.about-grid {
  display: grid;
  grid-template-columns: 0.95fr 1.05fr;
  gap: 56px;
}
.about p { color: var(--muted); margin-bottom: 14px; }
.about strong { color: var(--text); }
.about-sub {
  color: var(--text) !important;
  font-weight: 600;
  margin: 24px 0 14px;
}
.chip-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
}
.chip-list li {
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 8px 14px;
  border-radius: 10px;
  font-size: 0.86rem;
  color: var(--muted);
  transition: border-color 0.2s ease, color 0.2s ease;
}
.chip-list li:hover { border-color: var(--primary); color: var(--text); }

/* ---------- Cards / grids ---------- */
.card-grid { display: grid; gap: 22px; }
.expertise-grid { grid-template-columns: repeat(3, 1fr); }
.awards-grid { grid-template-columns: repeat(3, 1fr); }

.info-card,
.award-card {
  padding: 30px;
  border-radius: var(--radius);
  position: relative;
  overflow: hidden;
  transition: transform 0.3s ease, border-color 0.3s ease;
}
.info-card::after,
.award-card::after {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.35s ease;
}
.info-card:hover,
.award-card:hover {
  transform: translateY(-6px);
  border-color: rgba(91, 140, 255, 0.4);
}
.info-card:hover::after,
.award-card:hover::after { transform: scaleX(1); }

.icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(91, 140, 255, 0.18), rgba(139, 92, 246, 0.18));
  border: 1px solid var(--border);
  color: var(--accent);
  font-family: 'Sora', sans-serif;
  font-weight: 700;
  margin-bottom: 18px;
}
.info-card h3,
.award-card h3,
.timeline-content h3,
.research-item h3 {
  margin-bottom: 10px;
  font-size: 1.12rem;
}
.info-card p,
.award-card p,
.timeline-content p,
.research-item p,
.quote-card p {
  color: var(--muted);
  font-size: 0.96rem;
}
.award-icon {
  display: inline-block;
  font-size: 1.6rem;
  margin-bottom: 14px;
}

/* ---------- Timeline ---------- */
.timeline {
  position: relative;
  max-width: 820px;
  margin: 0 auto;
}
.timeline::before {
  content: '';
  position: absolute;
  left: 9px; top: 6px; bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--primary), var(--primary-2), transparent);
}
.timeline-item {
  position: relative;
  padding-left: 44px;
  margin-bottom: 22px;
}
.timeline-marker {
  position: absolute;
  left: 0; top: 22px;
  width: 20px; height: 20px;
  border-radius: 50%;
  background: var(--primary);
  border: 4px solid var(--bg-2);
  box-shadow: 0 0 0 4px rgba(91, 140, 255, 0.2);
}
.timeline-content {
  padding: 22px 26px;
  border-radius: var(--radius);
  transition: transform 0.25s ease;
}
.timeline-content:hover { transform: translateX(4px); }
.timeline-date {
  display: inline-block;
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  margin-bottom: 8px;
}

/* ---------- Research ---------- */
.research-list { display: grid; gap: 18px; }
.research-item {
  display: grid;
  grid-template-columns: 130px 1fr;
  gap: 24px;
  align-items: center;
  padding: 24px 28px;
  border-radius: var(--radius);
  transition: transform 0.25s ease, border-color 0.25s ease;
}
.research-item:hover {
  transform: translateY(-4px);
  border-color: rgba(34, 211, 238, 0.4);
}
.research-year {
  font-family: 'Sora', sans-serif;
  font-weight: 800;
  font-size: 1.05rem;
  color: var(--accent);
}

/* ---------- Education ---------- */
.education-grid {
  display: grid;
  grid-template-columns: 0.95fr 1.05fr;
  gap: 56px;
  align-items: start;
}
.education-list { display: grid; gap: 4px; }
.education-list div {
  padding: 20px 0;
  border-bottom: 1px solid var(--border-soft);
}
.education-list strong {
  display: block;
  font-family: 'Sora', sans-serif;
  font-size: 1.05rem;
  margin-bottom: 4px;
}
.education-list span { color: var(--muted); font-size: 0.92rem; }

/* ---------- Testimonials ---------- */
.testimonial-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 22px;
}
.recs-all {
  margin-top: 36px;
  text-align: center;
}
.quote-card {
  padding: 30px;
  border-radius: var(--radius);
  position: relative;
}
.quote-card::before {
  content: '“';
  position: absolute;
  top: 6px; right: 22px;
  font-family: 'Sora', serif;
  font-size: 4rem;
  color: rgba(91, 140, 255, 0.18);
  line-height: 1;
}
.quote-card p { font-size: 1rem; color: var(--text); }
.quote-author {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-top: 22px;
}
.quote-avatar {
  width: 44px; height: 44px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--primary-2));
  font-size: 0.85rem;
  font-weight: 700;
  color: #fff;
  flex-shrink: 0;
}
.quote-author strong { display: block; font-size: 0.96rem; }
.quote-author span { color: var(--muted); font-size: 0.84rem; }

/* ---------- Blog ---------- */
.blog-heading {
  max-width: none;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}
.blog-all { white-space: nowrap; }
.blog-grid { grid-template-columns: repeat(3, 1fr); }

.blog-card {
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform 0.3s ease, border-color 0.3s ease;
}
.blog-card:hover {
  transform: translateY(-6px);
  border-color: rgba(91, 140, 255, 0.4);
}
.blog-cover {
  display: flex;
  align-items: flex-end;
  height: 150px;
  padding: 16px;
  position: relative;
  overflow: hidden;
}
.blog-cover::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 70% 20%, rgba(255, 255, 255, 0.22), transparent 55%);
}
.cover-ai { background: linear-gradient(135deg, #3b6cf6, #8b5cf6); }
.cover-chain { background: linear-gradient(135deg, #8b5cf6, #22d3ee); }
.cover-transport { background: linear-gradient(135deg, #22d3ee, #3b6cf6); }
.cover-emerald { background: linear-gradient(135deg, #10b981, #0891b2); }
.cover-indigo { background: linear-gradient(135deg, #6366f1, #22d3ee); }
.cover-azure { background: linear-gradient(135deg, #0ea5e9, #6366f1); }
.cover-violet { background: linear-gradient(135deg, #7c3aed, #ec4899); }
.cover-amber { background: linear-gradient(135deg, #f59e0b, #ef4444); }
.cover-slate { background: linear-gradient(135deg, #64748b, #334155); }
.cover-rose { background: linear-gradient(135deg, #f43f5e, #8b5cf6); }
.blog-cat {
  position: relative;
  z-index: 1;
  background: rgba(0, 0, 0, 0.25);
  border: 1px solid rgba(255, 255, 255, 0.25);
  color: #fff;
  padding: 6px 12px;
  border-radius: 999px;
  font-size: 0.76rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}
.blog-body { padding: 24px; display: flex; flex-direction: column; gap: 10px; flex: 1; }
.blog-meta {
  color: var(--muted-dim);
  font-size: 0.82rem;
  letter-spacing: 0.02em;
}
.blog-card h3 { font-size: 1.14rem; }
.blog-card h3 a { transition: color 0.2s ease; }
.blog-card h3 a:hover { color: var(--primary); }
.blog-card .blog-body > p { color: var(--muted); font-size: 0.95rem; }
.blog-link {
  margin-top: auto;
  color: var(--accent);
  font-weight: 600;
  font-size: 0.92rem;
  width: fit-content;
  transition: transform 0.2s ease;
}
.blog-link:hover { transform: translateX(3px); }

/* ---------- Article / blog post pages ---------- */
.article { padding: 56px 0 40px; }
.article-wrap { width: min(100% - 48px, 760px); margin: 0 auto; }
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--accent);
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 28px;
  transition: transform 0.2s ease;
}
.back-link:hover { transform: translateX(-3px); }
.article-cat {
  display: inline-block;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--accent);
  padding: 6px 14px;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  margin-bottom: 18px;
}
.article h1 {
  font-size: clamp(2rem, 4vw, 3.1rem);
  margin-bottom: 18px;
}
.article-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--muted-dim);
  font-size: 0.9rem;
  margin-bottom: 32px;
}
.article-meta .dot { width: 4px; height: 4px; border-radius: 50%; background: var(--muted-dim); }
.article-cover {
  height: 220px;
  border-radius: var(--radius);
  margin-bottom: 40px;
  position: relative;
  overflow: hidden;
}
.article-cover::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 70% 20%, rgba(255, 255, 255, 0.22), transparent 55%);
}
.prose { font-size: 1.06rem; color: var(--muted); }
.prose > * + * { margin-top: 22px; }
.prose h2 {
  font-size: 1.5rem;
  color: var(--text);
  margin-top: 44px;
}
.prose h3 { font-size: 1.18rem; color: var(--text); margin-top: 32px; }
.prose p { line-height: 1.8; }
.prose strong { color: var(--text); }
.prose a { color: var(--accent); text-decoration: underline; text-underline-offset: 3px; }
.prose ul, .prose ol { padding-left: 22px; }
.prose li { margin-top: 10px; line-height: 1.7; }
.prose blockquote {
  border-left: 3px solid var(--brand);
  padding: 6px 0 6px 22px;
  margin: 32px 0;
  color: var(--text);
  font-size: 1.2rem;
  font-family: 'Sora', sans-serif;
  line-height: 1.5;
}
.prose code {
  background: var(--surface-strong);
  border: 1px solid var(--border-soft);
  padding: 2px 7px;
  border-radius: 6px;
  font-size: 0.92em;
  font-family: ui-monospace, 'SF Mono', Menlo, Consolas, monospace;
}
.prose pre {
  background: #0b1224;
  color: #d7e0fb;
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 12px;
  padding: 18px 20px;
  margin-top: 24px;
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.65;
  -webkit-overflow-scrolling: touch;
}
.prose pre code {
  background: none;
  border: 0;
  padding: 0;
  font-size: inherit;
  color: inherit;
}
.prose figcaption {
  color: var(--muted-dim);
  font-size: 0.84rem;
  margin-top: 8px;
  text-align: center;
}
.article-foot {
  margin-top: 48px;
  padding-top: 28px;
  border-top: 1px solid var(--border-soft);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}
.article-foot .byline { display: flex; align-items: center; gap: 12px; }
.article-foot .byline img,
.article-foot .byline .avatar-fallback {
  width: 44px; height: 44px; border-radius: 50%; object-fit: cover; object-position: center 18%;
}
.article-foot .byline .avatar-fallback {
  display: grid; place-items: center;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  color: #fff; font-weight: 700; font-size: 0.85rem;
}
.article-foot strong { display: block; }
.article-foot span { color: var(--muted); font-size: 0.88rem; }

/* blog index page */
.blog-archive { padding-top: 48px; }
.archive-group-title {
  font-size: 1.45rem;
  margin: 64px 0 26px;
  display: flex;
  align-items: baseline;
  gap: 12px;
  flex-wrap: wrap;
}
.archive-group-title::before {
  content: '';
  width: 22px;
  height: 3px;
  border-radius: 3px;
  background: linear-gradient(90deg, var(--brand), var(--accent));
  align-self: center;
}
.archive-group-title span {
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 500;
  font-family: 'Inter', sans-serif;
}

/* ---------- Contact ---------- */
.contact-panel {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  padding: 52px;
  border-radius: 28px;
  position: relative;
  overflow: hidden;
}
.contact-panel::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 0% 0%, rgba(139, 92, 246, 0.16), transparent 55%);
  pointer-events: none;
}
.contact-intro p { color: var(--muted); }
.contact-socials {
  display: flex;
  gap: 12px;
  margin-top: 24px;
}
.contact-socials a {
  width: 44px; height: 44px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  background: var(--surface);
  border: 1px solid var(--border);
  font-weight: 700;
  color: var(--muted);
  transition: all 0.2s ease;
}
.contact-socials a:hover {
  color: #fff;
  border-color: var(--primary);
  background: linear-gradient(135deg, rgba(91, 140, 255, 0.25), rgba(139, 92, 246, 0.25));
  transform: translateY(-2px);
}
.contact-form {
  display: grid;
  gap: 14px;
  position: relative;
}
.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 14px 16px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
  font-family: inherit;
  font-size: 0.95rem;
  outline: none;
  transition: border-color 0.2s ease, background 0.2s ease;
}
.contact-form input:focus,
.contact-form textarea:focus {
  border-color: var(--primary);
  background: rgba(91, 140, 255, 0.06);
}
.contact-form input::placeholder,
.contact-form textarea::placeholder { color: var(--muted-dim); }

.honeypot {
  position: absolute;
  left: -9999px;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}
.human-check {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}
.human-check label {
  color: var(--muted);
  font-size: 0.92rem;
}
.human-check input {
  width: 96px;
  text-align: center;
  font-weight: 600;
}
.form-error {
  color: #f87171;
  font-size: 0.88rem;
  margin: -4px 0 0;
}
[data-theme='light'] .form-error { color: #dc2626; }

/* ---------- Footer ---------- */
.site-footer {
  padding: 36px 0 48px;
  border-top: 1px solid var(--border-soft);
}
.footer-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--muted);
  font-size: 0.9rem;
  gap: 16px;
  flex-wrap: wrap;
}
.footer-links { display: flex; gap: 18px; }
.footer-links a:hover { color: var(--text); }

/* ---------- Scroll reveal ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
[data-reveal].revealed {
  opacity: 1;
  transform: none;
}

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .hero-grid,
  .about-grid,
  .education-grid,
  .contact-panel,
  .expertise-grid,
  .awards-grid,
  .testimonial-grid,
  .blog-grid {
    grid-template-columns: 1fr;
  }
  .section { padding: 80px 0; }
  .hero { padding-top: 80px; }
  .hero-copy h1 { max-width: 100%; }
  .contact-panel { padding: 36px 26px; }
}

@media (max-width: 1024px) {
  .nav-toggle { display: block; z-index: 1100; }
  .nav-links {
    position: fixed;
    inset: 74px 0 auto 0;
    background: var(--nav-bg);
    backdrop-filter: blur(16px);
    flex-direction: column;
    align-items: flex-start;
    padding: 24px;
    gap: 18px;
    display: none;
    border-bottom: 1px solid var(--border);
  }
  .nav-links.open { display: flex; }
  .nav-cta { width: 100%; }
}

@media (max-width: 768px) {
  .hero-actions { flex-direction: column; align-items: stretch; }
  .research-item { grid-template-columns: 1fr; gap: 8px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  [data-reveal] { opacity: 1; transform: none; }
}