/* ============================================================
   ROOT & RESET
   ============================================================ */
:root {
  --bg: #050b18;
  --bg-surface: #0d1b2a;
  --bg-card: #0f2035;
  --border: rgba(14, 165, 233, 0.12);
  --border-hover: rgba(14, 165, 233, 0.35);
  --blue: #0ea5e9;
  --cyan: #06b6d4;
  --lime: #84cc16;
  --purple: #a855f7;
  --gold: #f59e0b;
  --orange: #f97316;
  --red: #ef4444;
  --green: #22c55e;
  --gray-badge: #64748b;
  --text: #e2e8f0;
  --text-muted: #64748b;
  --text-dim: #94a3b8;
  --glow-blue: 0 0 20px rgba(14, 165, 233, 0.35);
  --glow-cyan: 0 0 20px rgba(6, 182, 212, 0.35);
  --radius: 12px;
  --radius-sm: 8px;
  --nav-h: 64px;
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-h);
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Space Grotesk', sans-serif;
  line-height: 1.7;
  overflow-x: hidden;
}

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

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ============================================================
   NAV
   ============================================================ */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 32px;
  background: rgba(5, 11, 24, 0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
  transition: border-color var(--transition);
}

.nav.scrolled { border-bottom-color: var(--border-hover); }

.nav-logo {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--blue);
  letter-spacing: 0.02em;
}

.nav-logo-bracket { color: var(--cyan); }

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

.nav-links a {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  color: var(--text-dim);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
}

.nav-links a:hover { color: var(--blue); background: rgba(14, 165, 233, 0.08); }

.nav-links a.nav-cta {
  color: var(--blue);
  border: 1px solid rgba(14, 165, 233, 0.4);
  padding: 6px 16px;
}

.nav-links a.nav-cta:hover {
  background: rgba(14, 165, 233, 0.12);
  border-color: var(--blue);
  box-shadow: var(--glow-blue);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-dim);
  border-radius: 2px;
  transition: var(--transition);
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: var(--nav-h) 24px 80px;
}

#heroCanvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0.45;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 780px;
  text-align: center;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  color: var(--lime);
  background: rgba(132, 204, 22, 0.08);
  border: 1px solid rgba(132, 204, 22, 0.25);
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 28px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.hero-tag-dot {
  width: 6px; height: 6px;
  background: var(--lime);
  border-radius: 50%;
  animation: pulse-dot 2s ease-in-out infinite;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.7); }
}

.hero-title {
  font-size: clamp(2.8rem, 7vw, 5rem);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #ffffff 0%, #94a3b8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-typewriter {
  font-family: 'JetBrains Mono', monospace;
  font-size: clamp(1rem, 2.5vw, 1.35rem);
  color: var(--cyan);
  margin-bottom: 24px;
  min-height: 2em;
}

.hero-prompt { color: var(--text-muted); }

.hero-cursor {
  display: inline-block;
  animation: blink 1.1s step-end infinite;
  color: var(--blue);
}

@keyframes blink { 0%, 100% { opacity: 1; } 50% { opacity: 0; } }

.hero-sub {
  font-size: 1.05rem;
  color: var(--text-dim);
  max-width: 580px;
  margin: 0 auto 36px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 56px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  transition: all var(--transition);
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--blue), var(--cyan));
  color: #fff;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(14, 165, 233, 0.4);
}

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

.btn-ghost:hover {
  color: var(--blue);
  border-color: var(--border-hover);
  background: rgba(14, 165, 233, 0.06);
  transform: translateY(-2px);
}

.hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  flex-wrap: wrap;
  background: rgba(13, 27, 42, 0.7);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  backdrop-filter: blur(12px);
  padding: 20px 32px;
  gap: 0;
}

.stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 0 28px;
}

.stat-value {
  font-size: 2rem;
  font-weight: 700;
  color: var(--blue);
  line-height: 1.1;
  font-family: 'Space Grotesk', sans-serif;
}

.stat-plus { color: var(--cyan); font-size: 1.4rem; }

.stat-label {
  font-size: 0.72rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-top: 4px;
  font-family: 'JetBrains Mono', monospace;
}

.stat-divider {
  width: 1px;
  height: 40px;
  background: var(--border);
}

.hero-scroll {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.65rem;
  color: var(--text-muted);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  animation: fadeInUp 1s 1.5s both;
}

.hero-scroll-line {
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, var(--blue), transparent);
  animation: scroll-pulse 2s ease-in-out infinite;
}

@keyframes scroll-pulse {
  0%, 100% { opacity: 0.3; transform: scaleY(1); }
  50% { opacity: 1; transform: scaleY(0.6); }
}

/* ============================================================
   SECTIONS
   ============================================================ */
.section {
  padding: 100px 0;
}

.section-dark { background: var(--bg-surface); }

.section-header {
  margin-bottom: 56px;
}

.section-tag {
  display: block;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  color: var(--cyan);
  margin-bottom: 10px;
  letter-spacing: 0.05em;
}

.section-title {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
}

/* ============================================================
   ABOUT
   ============================================================ */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
}

.about-text p {
  color: var(--text-dim);
  margin-bottom: 18px;
  font-size: 1.02rem;
}

.about-text strong { color: var(--text); }

.about-cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.about-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}

.about-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: var(--glow-blue);
}

.about-card-icon {
  color: var(--blue);
  margin-bottom: 12px;
}

.about-card h3 {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 8px;
}

.about-card p {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ============================================================
   SKILLS
   ============================================================ */
.skills-groups {
  display: flex;
  flex-direction: column;
  gap: 36px;
}

.skill-group-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-dim);
  margin-bottom: 14px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-family: 'JetBrains Mono', monospace;
  display: flex;
  align-items: center;
  gap: 8px;
}

.skill-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.badge {
  padding: 6px 14px;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 500;
  border: 1px solid transparent;
  transition: all var(--transition);
  cursor: default;
}

.badge:hover { transform: translateY(-2px); }

.badge-blue   { background: rgba(14,165,233,0.1);  color: #38bdf8; border-color: rgba(14,165,233,0.25); }
.badge-blue:hover   { background: rgba(14,165,233,0.2);  box-shadow: 0 0 16px rgba(14,165,233,0.3); }

.badge-cyan   { background: rgba(6,182,212,0.1);   color: #22d3ee; border-color: rgba(6,182,212,0.25); }
.badge-cyan:hover   { background: rgba(6,182,212,0.2);   box-shadow: 0 0 16px rgba(6,182,212,0.3); }

.badge-lime   { background: rgba(132,204,22,0.1);  color: #a3e635; border-color: rgba(132,204,22,0.25); }
.badge-lime:hover   { background: rgba(132,204,22,0.2);  box-shadow: 0 0 16px rgba(132,204,22,0.3); }

.badge-purple { background: rgba(168,85,247,0.1);  color: #c084fc; border-color: rgba(168,85,247,0.25); }
.badge-purple:hover { background: rgba(168,85,247,0.2);  box-shadow: 0 0 16px rgba(168,85,247,0.3); }

.badge-gold   { background: rgba(245,158,11,0.1);  color: #fbbf24; border-color: rgba(245,158,11,0.25); }
.badge-gold:hover   { background: rgba(245,158,11,0.2);  box-shadow: 0 0 16px rgba(245,158,11,0.3); }

.badge-orange { background: rgba(249,115,22,0.1);  color: #fb923c; border-color: rgba(249,115,22,0.25); }

.badge-green  { background: rgba(34,197,94,0.1);   color: #4ade80; border-color: rgba(34,197,94,0.25); }

.badge-red    { background: rgba(239,68,68,0.1);   color: #f87171; border-color: rgba(239,68,68,0.25); }

.badge-gray   { background: rgba(100,116,139,0.1); color: #94a3b8; border-color: rgba(100,116,139,0.25); }
.badge-gray:hover   { background: rgba(100,116,139,0.2); box-shadow: 0 0 16px rgba(100,116,139,0.25); }

/* ============================================================
   TIMELINE
   ============================================================ */
.timeline {
  position: relative;
  padding-left: 32px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 12px;
  bottom: 12px;
  width: 2px;
  background: linear-gradient(to bottom, var(--blue), transparent);
}

.timeline-item {
  position: relative;
  margin-bottom: 40px;
}

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

.timeline-marker {
  position: absolute;
  left: -28px;
  top: 14px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 2px solid var(--border);
  background: var(--bg);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.timeline-item-active .timeline-marker {
  border-color: var(--blue);
  background: var(--blue);
  box-shadow: 0 0 12px rgba(14, 165, 233, 0.6);
}

.timeline-content {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 28px;
  transition: border-color var(--transition), transform var(--transition);
}

.timeline-content:hover {
  border-color: var(--border-hover);
  transform: translateX(4px);
}

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

.timeline-role {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
}

.timeline-company {
  display: block;
  font-size: 0.85rem;
  color: var(--blue);
  margin-top: 2px;
  font-family: 'JetBrains Mono', monospace;
}

.timeline-period {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.78rem;
  color: var(--text-muted);
  white-space: nowrap;
  padding-top: 3px;
}

.timeline-desc {
  font-size: 0.9rem;
  color: var(--text-dim);
  margin-bottom: 14px;
  line-height: 1.7;
}

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

.timeline-tags span {
  font-size: 0.75rem;
  font-family: 'JetBrains Mono', monospace;
  color: var(--cyan);
  background: rgba(6, 182, 212, 0.08);
  border: 1px solid rgba(6, 182, 212, 0.2);
  padding: 3px 10px;
  border-radius: 4px;
}

/* ============================================================
   ARTICLES
   ============================================================ */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  align-items: start;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  position: relative;
  transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}

.article-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: var(--glow-blue);
}

.article-card-featured {
  grid-column: 1 / 3;
  border-color: rgba(14, 165, 233, 0.25);
  background: linear-gradient(135deg, rgba(14,165,233,0.06) 0%, rgba(6,182,212,0.03) 100%);
}

.article-card-badge {
  display: inline-block;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.7rem;
  padding: 3px 10px;
  border-radius: 999px;
  background: rgba(132, 204, 22, 0.12);
  color: var(--lime);
  border: 1px solid rgba(132, 204, 22, 0.3);
  margin-bottom: 14px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.article-card-badge-soon {
  background: rgba(100, 116, 139, 0.12);
  color: var(--text-muted);
  border-color: rgba(100, 116, 139, 0.2);
}

.article-card-tag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem;
  color: var(--cyan);
  margin-bottom: 12px;
}

.article-card h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 12px;
  line-height: 1.4;
}

.article-card p {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 16px;
}

.article-metrics {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-bottom: 20px;
}

.article-metrics span {
  font-size: 0.78rem;
  font-family: 'JetBrains Mono', monospace;
  color: var(--text-muted);
}

.article-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--blue);
  transition: gap var(--transition), color var(--transition);
}

.article-link:hover { gap: 10px; color: var(--cyan); }

/* ============================================================
   CERTIFICATIONS
   ============================================================ */
.certs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 14px;
}

.cert-card {
  display: flex;
  align-items: center;
  gap: 16px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  transition: border-color var(--transition), transform var(--transition);
}

.cert-card:hover {
  border-color: var(--border-hover);
  transform: translateX(4px);
}

.cert-icon {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  font-weight: 700;
  flex-shrink: 0;
}

.cert-icon-azure     { background: rgba(14,165,233,0.15);  color: var(--blue);   border: 1px solid rgba(14,165,233,0.3); }
.cert-icon-oracle    { background: rgba(239,68,68,0.12);   color: #f87171;       border: 1px solid rgba(239,68,68,0.25); }
.cert-icon-databricks{ background: rgba(245,158,11,0.12);  color: #fbbf24;       border: 1px solid rgba(245,158,11,0.25); }

.cert-vendor {
  display: block;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.68rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 3px;
}

.cert-name {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text);
}

/* ============================================================
   EDUCATION
   ============================================================ */
.edu-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.edu-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: border-color var(--transition), transform var(--transition);
}

.edu-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
}

.edu-card-active {
  border-color: rgba(14, 165, 233, 0.3);
  background: linear-gradient(135deg, rgba(14,165,233,0.06), rgba(6,182,212,0.03));
}

.edu-status {
  display: inline-block;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.7rem;
  padding: 3px 10px;
  border-radius: 999px;
  background: rgba(14, 165, 233, 0.12);
  color: var(--blue);
  border: 1px solid rgba(14, 165, 233, 0.3);
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.edu-status-done {
  background: rgba(100,116,139,0.12);
  color: var(--text-muted);
  border-color: rgba(100,116,139,0.2);
}

.edu-degree {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 6px;
}

.edu-institution {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  color: var(--cyan);
  margin-bottom: 4px;
}

.edu-period {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 14px;
  font-family: 'JetBrains Mono', monospace;
}

.edu-desc {
  font-size: 0.88rem;
  color: var(--text-dim);
  line-height: 1.7;
}

/* ============================================================
   CONTACT
   ============================================================ */
.contact-wrapper {
  max-width: 600px;
}

.contact-text {
  font-size: 1.05rem;
  color: var(--text-dim);
  margin-bottom: 36px;
  line-height: 1.8;
}

.contact-links {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}

.contact-link {
  display: flex;
  align-items: center;
  gap: 14px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 24px;
  min-width: 200px;
  transition: all var(--transition);
  color: var(--text-dim);
}

.contact-link:hover {
  border-color: var(--blue);
  color: var(--blue);
  transform: translateY(-4px);
  box-shadow: var(--glow-blue);
}

.contact-link span { font-weight: 600; font-size: 0.95rem; }
.contact-link small { display: block; font-size: 0.78rem; color: var(--text-muted); font-family: 'JetBrains Mono', monospace; }

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  border-top: 1px solid var(--border);
  padding: 28px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.footer-logo {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.95rem;
  color: var(--blue);
}

.footer-copy {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.footer-stack {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ============================================================
   KOREAN CULTURE CARD
   ============================================================ */
.about-card-korea {
  border-color: rgba(205, 46, 46, 0.3);
  background: linear-gradient(135deg, rgba(205, 46, 46, 0.06) 0%, rgba(255, 200, 50, 0.04) 100%);
  grid-column: 1 / -1;
}

.about-card-korea:hover {
  border-color: rgba(205, 46, 46, 0.5);
  box-shadow: 0 0 24px rgba(205, 46, 46, 0.2);
}

.about-card-icon-korea {
  font-size: 2rem;
  margin-bottom: 12px;
  line-height: 1;
}

/* ============================================================
   LANGUAGE SWITCHER
   ============================================================ */
.lang-switcher {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: 8px;
  padding-left: 12px;
  border-left: 1px solid var(--border);
}

.lang-btn {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem;
  color: var(--text-muted);
  background: none;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  padding: 4px 8px;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

.lang-btn:hover {
  color: var(--blue);
  border-color: var(--border);
  background: rgba(14, 165, 233, 0.06);
}

.lang-btn-active {
  color: var(--blue);
  border-color: rgba(14, 165, 233, 0.35);
  background: rgba(14, 165, 233, 0.08);
}

/* ============================================================
   SCROLL REVEAL
   ============================================================ */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.65s cubic-bezier(0.4,0,0.2,1), transform 0.65s cubic-bezier(0.4,0,0.2,1);
}

.reveal.visible {
  opacity: 1;
  transform: none;
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: none; }
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 900px) {
  .about-grid { grid-template-columns: 1fr; gap: 40px; }
  .articles-grid { grid-template-columns: 1fr; }
  .edu-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .nav-links { display: none; position: fixed; top: var(--nav-h); left: 0; right: 0; background: rgba(5,11,24,0.97); backdrop-filter: blur(16px); flex-direction: column; padding: 20px 24px; border-bottom: 1px solid var(--border); }
  .nav-links.open { display: flex; }
  .nav-toggle { display: flex; }
  .hero-stats { gap: 0; padding: 16px; }
  .stat { padding: 0 16px; }
  .stat-value { font-size: 1.5rem; }
  .about-cards { grid-template-columns: 1fr; }
  .timeline { padding-left: 24px; }
  .timeline-header { flex-direction: column; gap: 4px; }
  .certs-grid { grid-template-columns: 1fr; }
  .footer-inner { flex-direction: column; text-align: center; }
}

@media (max-width: 480px) {
  .hero-actions { flex-direction: column; align-items: stretch; }
  .btn { justify-content: center; }
  .stat-divider { display: none; }
  .hero-stats { flex-direction: column; gap: 16px; }
  .stat { padding: 0; }
  .contact-links { flex-direction: column; }
  .contact-link { min-width: unset; }
}