/* ============================================================
   DESIGN TOKENS
   ============================================================ */
:root {
  --bg:        #f0f4f8;
  --surface:   #ffffff;
  --surface2:  #e4ecf2;
  --border:    rgba(15,23,42,0.1);
  --accent:    #0284c7;
  --accent2:   #6366f1;
  --green:     #059669;
  --text:      #0f172a;
  --muted:     #334155;
  --faint:     #64748b;
  --radius:    12px;
  --radius-lg: 20px;
  --nav-h:     64px;
  --transition: 0.25s cubic-bezier(0.4,0,0.2,1);
}

/* ============================================================
   RESET & BASE
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; font-size: 17px; }

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

img { max-width: 100%; display: block; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

/* ============================================================
   SCROLLBAR
   ============================================================ */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--surface); }
::-webkit-scrollbar-thumb { background: var(--faint); border-radius: 3px; }

/* ============================================================
   SELECTION
   ============================================================ */
::selection { background: rgba(2,132,199,0.18); }

/* ============================================================
   LAYOUT HELPERS
   ============================================================ */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

section {
  padding: 100px 0;
}

.section-label {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  color: var(--text);
  margin-bottom: 16px;
}

.section-subtitle {
  color: var(--muted);
  font-size: 1.05rem;
  max-width: 600px;
  margin-bottom: 56px;
}

/* ============================================================
   NAVIGATION
   ============================================================ */
nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-h);
  z-index: 100;
  background: rgba(240,244,248,0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  transition: background var(--transition);
}

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-weight: 700;
  font-size: 1rem;
  color: var(--text);
  letter-spacing: -0.01em;
}

.nav-logo span { color: var(--accent); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
}

.nav-links a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--muted);
  padding: 6px 12px;
  border-radius: 8px;
  transition: color var(--transition), background var(--transition);
}

.nav-links a:hover {
  color: var(--text);
  background: rgba(15,23,42,0.05);
  text-decoration: none;
}

.nav-links .btn-nav {
  color: var(--accent);
  border: 1px solid rgba(2,132,199,0.35);
  background: rgba(2,132,199,0.07);
}

.nav-links .btn-nav:hover {
  background: rgba(2,132,199,0.14);
  color: var(--accent);
}

/* ============================================================
   HERO
   ============================================================ */
#hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  position: relative;
  padding: 100px 0 80px;
  overflow: hidden;
}

/* Animated gradient blobs */
#hero::before {
  content: '';
  position: absolute;
  width: 600px;
  height: 600px;
  top: -100px;
  right: -150px;
  background: radial-gradient(ellipse, rgba(99,102,241,0.1) 0%, transparent 70%);
  animation: blob1 12s ease-in-out infinite;
  pointer-events: none;
}

#hero::after {
  content: '';
  position: absolute;
  width: 500px;
  height: 500px;
  bottom: -80px;
  left: -100px;
  background: radial-gradient(ellipse, rgba(2,132,199,0.08) 0%, transparent 70%);
  animation: blob2 15s ease-in-out infinite;
  pointer-events: none;
}

@keyframes blob1 {
  0%, 100% { transform: translate(0,0) scale(1); }
  33%       { transform: translate(-40px, 60px) scale(1.1); }
  66%       { transform: translate(30px, -40px) scale(0.9); }
}

@keyframes blob2 {
  0%, 100% { transform: translate(0,0) scale(1); }
  50%       { transform: translate(60px, -50px) scale(1.15); }
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 260px;
  gap: 64px;
  align-items: center;
}

.hero-photo-wrap {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-photo {
  width: 190px;
  height: 260px;
  border-radius: 50%;
  overflow: hidden;
  border: 2px solid rgba(2,132,199,0.3);
  box-shadow:
    0 0 0 8px rgba(2,132,199,0.08),
    0 24px 64px rgba(15,23,42,0.15);
  flex-shrink: 0;
}

.hero-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.hero-name {
  font-size: clamp(3rem, 7vw, 5.5rem);
  font-weight: 800;
  color: var(--text);
  letter-spacing: -0.04em;
  line-height: 1;
  margin-bottom: 20px;
}

.hero-name .gradient-text {
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-title {
  font-size: clamp(1.1rem, 2vw, 1.4rem);
  font-weight: 400;
  color: var(--muted);
  margin-bottom: 28px;
  letter-spacing: -0.01em;
}

.hero-title strong {
  color: var(--text);
  font-weight: 600;
}

.hero-desc {
  font-size: 1.05rem;
  color: var(--muted);
  max-width: 620px;
  margin-bottom: 48px;
  line-height: 1.8;
}

.hero-ctas {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 64px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 12px 22px;
  border-radius: var(--radius);
  transition: all var(--transition);
  cursor: pointer;
  border: none;
  text-decoration: none;
}

.btn-primary {
  background: var(--accent);
  color: #ffffff;
}

.btn-primary:hover {
  background: #0369a1;
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(2,132,199,0.25);
  text-decoration: none;
  color: #ffffff;
}

.btn-secondary {
  background: var(--surface2);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: rgba(15,23,42,0.06);
  transform: translateY(-2px);
  text-decoration: none;
  color: var(--text);
}

.btn-ghost {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
}

.btn-ghost:hover {
  color: var(--text);
  background: rgba(15,23,42,0.05);
  text-decoration: none;
}

/* Hero skill tags */
.hero-skills {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 20px;
}

.hero-skill-tag {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--accent);
  background: rgba(2,132,199,0.08);
  border: 1px solid rgba(2,132,199,0.22);
  border-radius: 20px;
  padding: 4px 12px;
  letter-spacing: 0.01em;
}

/* Hero stats */
.hero-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 32px;
}

.stat-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.stat-value {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--text);
  letter-spacing: -0.03em;
  line-height: 1;
}

.stat-label {
  font-size: 0.75rem;
  color: var(--faint);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

/* ============================================================
   ABOUT
   ============================================================ */
#about {
  background: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.about-grid {
  display: grid;
  grid-template-columns: 3fr 2fr;
  gap: 64px;
  align-items: start;
}

.about-body p {
  color: var(--muted);
  margin-bottom: 20px;
  font-size: 1.05rem;
}

.about-body p:last-child { margin-bottom: 0; }

.about-sidebar {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.info-card {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.info-card h4 {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--faint);
  margin-bottom: 12px;
}

.info-row {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.875rem;
  color: var(--muted);
  margin-bottom: 8px;
}

.info-row:last-child { margin-bottom: 0; }

.info-row svg { flex-shrink: 0; color: var(--accent); }

.social-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 4px;
}

.social-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--muted);
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 6px 12px;
  border-radius: 8px;
  transition: all var(--transition);
}

.social-link:hover {
  color: var(--accent);
  border-color: rgba(2,132,199,0.35);
  background: rgba(2,132,199,0.07);
  text-decoration: none;
}

/* ============================================================
   EXPERIENCE TIMELINE
   ============================================================ */
#experience {
  padding: 100px 0;
}

.timeline {
  position: relative;
  padding-left: 32px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 8px;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--accent), var(--accent2), transparent);
}

.timeline-item {
  position: relative;
  margin-bottom: 48px;
}

.timeline-item:last-child { margin-bottom: 0; }

.timeline-dot {
  position: absolute;
  left: -38px;
  top: 6px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent);
  border: 3px solid var(--bg);
  box-shadow: 0 0 0 2px rgba(2,132,199,0.3);
}

.timeline-item:nth-child(2) .timeline-dot { background: var(--accent2); box-shadow: 0 0 0 2px rgba(99,102,241,0.3); }
.timeline-item:nth-child(3) .timeline-dot { background: var(--accent2); }
.timeline-item:nth-child(4) .timeline-dot { background: var(--faint); box-shadow: none; }

.timeline-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.timeline-role {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 2px;
}

.timeline-company {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--accent);
}

.timeline-period {
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--faint);
  background: var(--surface2);
  border: 1px solid var(--border);
  padding: 4px 10px;
  border-radius: 6px;
  white-space: nowrap;
  align-self: flex-start;
}

.timeline-body {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.timeline-body li {
  font-size: 0.9rem;
  color: var(--muted);
  padding-left: 16px;
  position: relative;
}

.timeline-body li::before {
  content: '›';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
}

/* ============================================================
   EDUCATION
   ============================================================ */
#education {
  background: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.edu-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

.edu-card {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: border-color var(--transition), transform var(--transition);
}

.edu-card:hover {
  border-color: rgba(2,132,199,0.3);
  transform: translateY(-4px);
}

.edu-degree {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 6px;
}

.edu-field {
  font-size: 0.875rem;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 4px;
}

.edu-uni {
  font-size: 0.85rem;
  color: var(--muted);
  margin-bottom: 2px;
}

.edu-year {
  font-size: 0.78rem;
  color: var(--faint);
}

/* ============================================================
   SKILLS
   ============================================================ */
#skills {
  padding: 100px 0;
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.skill-group {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
}

.skill-group-title {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.skill-group-title::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--muted);
  background: var(--surface2);
  border: 1px solid var(--border);
  padding: 5px 12px;
  border-radius: 6px;
  transition: all var(--transition);
}

.tag:hover {
  color: var(--accent);
  border-color: rgba(2,132,199,0.35);
  background: rgba(2,132,199,0.07);
}

/* ============================================================
   BLOG
   ============================================================ */
#blog {
  background: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
}

.blog-card {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}

.blog-card:hover {
  border-color: rgba(2,132,199,0.25);
  transform: translateY(-4px);
  box-shadow: 0 16px 48px rgba(15,23,42,0.08);
}

.blog-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.78rem;
  color: var(--faint);
}

.blog-date { font-variant-numeric: tabular-nums; }

.blog-card h3 {
  font-size: 1.05rem;
  color: var(--text);
  line-height: 1.4;
}

.blog-card h3 a {
  color: inherit;
  transition: color var(--transition);
}

.blog-card h3 a:hover {
  color: var(--accent);
  text-decoration: none;
}

.blog-excerpt {
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.7;
  flex: 1;
}

.blog-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.blog-tag {
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--accent2);
  background: rgba(129,140,248,0.1);
  border: 1px solid rgba(129,140,248,0.2);
  padding: 3px 9px;
  border-radius: 100px;
}

/* ============================================================
   SIMULATION
   ============================================================ */
#simulation {
  padding: 100px 0;
}

.simulation-wrap {
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--surface);
}

.simulation-wrap iframe {
  display: block;
  width: 100%;
  height: 735px;
  border: none;
}

/* ============================================================
   PUBLICATIONS
   ============================================================ */
#publications {
  background: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.pub-category {
  margin-bottom: 40px;
}

.pub-category:last-child { margin-bottom: 0; }

.pub-category-label {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.pub-category-label::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

.pub-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.pub-item {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  transition: border-color var(--transition);
}

.pub-item:hover {
  border-color: rgba(2,132,199,0.3);
}

.pub-title {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text);
  line-height: 1.4;
}

.pub-authors {
  font-size: 0.8rem;
  color: var(--faint);
}

.pub-venue {
  font-size: 0.78rem;
  color: var(--accent);
  font-style: italic;
}

.pub-links {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 6px;
}

.pub-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--accent);
  background: rgba(2,132,199,0.07);
  border: 1px solid rgba(2,132,199,0.22);
  padding: 3px 10px;
  border-radius: 6px;
  transition: all var(--transition);
  text-decoration: none;
}

.pub-link:hover {
  background: rgba(2,132,199,0.15);
  text-decoration: none;
}

/* ============================================================
   CONTACT / FOOTER
   ============================================================ */
#footer {
  padding: 60px 0;
}

.footer-inner {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
}

.footer-name {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text);
  letter-spacing: -0.02em;
}

.footer-email {
  font-size: 0.9rem;
  color: var(--muted);
}

.footer-email a { color: var(--accent); }

.footer-socials {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}

.footer-legal {
  font-size: 0.78rem;
  color: var(--faint);
}

/* ============================================================
   DIVIDER
   ============================================================ */
.divider {
  width: 48px;
  height: 3px;
  background: linear-gradient(to right, var(--accent), var(--accent2));
  border-radius: 2px;
  margin-bottom: 40px;
}

/* ============================================================
   BLOG POST PROSE
   ============================================================ */
.post-header {
  padding: calc(var(--nav-h) + 60px) 0 48px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 56px;
}

.post-header .section-label { margin-bottom: 16px; }

.post-title {
  font-size: clamp(1.8rem, 4vw, 3rem);
  font-weight: 800;
  color: var(--text);
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 20px;
}

.post-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 0.85rem;
  color: var(--faint);
}

.post-meta-date { font-variant-numeric: tabular-nums; }

.prose {
  max-width: 720px;
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--muted);
  text-align: justify;
}

.prose h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
  margin: 48px 0 16px;
  letter-spacing: -0.02em;
}

.prose h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text);
  margin: 32px 0 12px;
  letter-spacing: -0.01em;
}

.prose p {
  margin-bottom: 20px;
}

.prose p:last-child { margin-bottom: 0; }

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

.prose a { color: var(--accent); }

.prose ul, .prose ol {
  padding-left: 24px;
  margin-bottom: 20px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.prose li { color: var(--muted); }

.prose hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 40px 0;
}

.prose blockquote {
  border-left: 3px solid var(--accent);
  padding: 4px 20px;
  margin: 24px 0;
  color: var(--faint);
  font-style: italic;
}

/* Inline code */
.prose code {
  font-family: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', Consolas, monospace;
  font-size: 0.875em;
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--accent2);
  padding: 2px 6px;
  border-radius: 5px;
}

/* Code blocks — stay dark for readability regardless of theme */
.prose pre {
  background: #1e2a3a;
  border: 1px solid rgba(255,255,255,0.07);
  border-radius: var(--radius);
  padding: 20px 24px;
  overflow-x: auto;
  margin: 24px 0;
  line-height: 1.65;
}

.prose pre code {
  font-size: 0.875rem;
  background: none;
  border: none;
  color: #e2e8f0;
  padding: 0;
  border-radius: 0;
}

/* Figures */
.prose figure {
  margin: 32px 0;
  text-align: center;
}

.prose figure img {
  border-radius: var(--radius);
  border: 1px solid var(--border);
  margin: 0 auto;
}

.prose figcaption {
  font-size: 0.82rem;
  color: var(--faint);
  margin-top: 10px;
  font-style: italic;
}

.prose .post-img {
  display: block;
  margin: 28px auto;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  max-width: 100%;
}

.prose .img-caption {
  text-align: center;
  font-size: 0.82rem;
  color: var(--faint);
  margin-top: -16px;
  margin-bottom: 28px;
  font-style: italic;
}

/* Iframe embeds */
.prose .embed-wrap {
  margin: 32px 0;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
}

.prose .embed-wrap iframe {
  display: block;
  width: 100%;
  border: none;
}

/* Wide Plotly charts (1050px source): scale to fit prose width (720px) */
.prose .embed-wrap-plotly {
  margin: 32px 0;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  overflow: hidden;
  height: 446px; /* 650 * (720/1050) */
}

.prose .embed-wrap-plotly iframe {
  display: block;
  border: none;
  width: 1050px;
  height: 650px;
  transform: scale(0.686);   /* 720/1050 */
  transform-origin: top left;
}

/* Two-column post layout: prose + TOC sidebar */
.post-body-grid {
  display: grid;
  grid-template-columns: 1fr 210px;
  gap: 56px;
  align-items: start;
}

/* TOC sidebar */
.post-toc {
  position: sticky;
  top: calc(var(--nav-h) + 28px);
}

.toc-label {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--faint);
  margin-bottom: 12px;
}

.post-toc ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 2px;
  border-left: 2px solid var(--border);
  padding-left: 14px;
}

.post-toc ul li a {
  font-size: 0.8rem;
  color: var(--faint);
  display: block;
  padding: 4px 0;
  transition: color var(--transition);
  line-height: 1.4;
}

.post-toc ul li a:hover,
.post-toc ul li a.active {
  color: var(--accent);
  text-decoration: none;
}

/* Post nav */
.post-nav {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-top: 64px;
  padding-top: 32px;
  border-top: 1px solid var(--border);
  flex-wrap: wrap;
}

.post-layout {
  padding-bottom: 80px;
}

/* ============================================================
   FADE-IN ANIMATION
   ============================================================ */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ============================================================
   HAMBURGER MENU
   ============================================================ */
.nav-burger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}

.nav-burger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.25s ease, opacity 0.25s ease;
}

body.nav-open .nav-burger span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
body.nav-open .nav-burger span:nth-child(2) { opacity: 0; }
body.nav-open .nav-burger span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.nav-dropdown {
  display: none;
  flex-direction: column;
  position: fixed;
  top: var(--nav-h);
  left: 0;
  right: 0;
  background: rgba(240,244,248,0.98);
  border-bottom: 1px solid var(--border);
  padding: 8px 24px 16px;
  box-shadow: 0 8px 24px rgba(15,23,42,0.08);
  z-index: 99;
}

.nav-dropdown a {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--muted);
  padding: 12px 8px;
  border-bottom: 1px solid var(--border);
  text-decoration: none;
  transition: color var(--transition);
}

.nav-dropdown a:last-child { border-bottom: none; }
.nav-dropdown a:hover { color: var(--text); }
.nav-dropdown .btn-nav { color: var(--accent); font-weight: 600; }

body.nav-open .nav-dropdown { display: flex; }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 768px) {
  section { padding: 72px 0; }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .nav-links { display: none; }

  .nav-burger { display: flex; }

  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .hero-photo-wrap { order: -1; }

  .hero-photo {
    width: 140px;
    height: 190px;
  }

  .hero-stats {
    gap: 24px;
  }

  .stat-value { font-size: 1.4rem; }
}

/* Blog: collapse to single column below 900px */
@media (max-width: 900px) {
  .post-body-grid {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .post-toc { display: none; }

  .prose { max-width: 100%; }

  .container { padding: 0 16px; }
}

@media (max-width: 480px) {
  .timeline { padding-left: 24px; }
  .timeline-dot { left: -30px; }
  .hero-ctas { flex-direction: column; }
  .hero-ctas .btn { text-align: center; justify-content: center; }
  .container { padding: 0 14px; }
}