/* =====================================================
   Muhammad S. Abdo — Academic Website
   Primary: Blue #2563eb  |  Light Mode
   ===================================================== */

/* ---------- CSS Variables ---------- */
:root {
  --crimson:        #2563eb;
  --crimson-light:  #3b82f6;
  --crimson-dim:    #1d4ed8;
  --crimson-glow:   rgba(37,99,235,.22);
  --crimson-subtle: rgba(37,99,235,.07);

  --bg:       #f8fafc;
  --bg-2:     #f1f5f9;
  --bg-card:  #ffffff;
  --bg-code:  #1e293b;
  --bg-nav:   rgba(248,250,252,.92);

  --text:     #0f172a;
  --text-2:   #475569;
  --text-3:   #94a3b8;
  --border:   #e2e8f0;
  --border-a: rgba(37,99,235,.22);

  --font:  'Inter', system-ui, sans-serif;
  --mono:  'JetBrains Mono', 'Fira Code', monospace;

  --ease:    cubic-bezier(.4,0,.2,1);
  --t3:      .3s;
  --t5:      .5s;
  --radius:  10px;
  --radius-lg: 16px;

  --shadow:   0 4px 24px rgba(15,23,42,.08);
  --shadow-c: 0 0 28px var(--crimson-glow);
  --max-w:    1160px;
}

/* ---------- Reset & Base ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: var(--crimson-light); text-decoration: none; transition: color var(--t3) var(--ease); }
a:hover { color: #ff3333; }
::selection { background: var(--crimson); color: #fff; }

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-2); }
::-webkit-scrollbar-thumb { background: #cbd5e1; border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--crimson-light); }

/* ---------- Utility ---------- */
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 24px; }
.section { padding: 100px 0; }
.section-sm { padding: 64px 0; }
.text-crimson { color: var(--crimson-light); }
.text-muted { color: var(--text-2); }
.mono { font-family: var(--mono); }
.tag {
  display: inline-block;
  background: var(--crimson-subtle);
  color: var(--crimson-light);
  border: 1px solid var(--border-a);
  border-radius: 4px;
  font-size: .75rem;
  font-weight: 600;
  letter-spacing: .04em;
  padding: 2px 10px;
  text-transform: uppercase;
}
.tag-gray {
  background: rgba(255,255,255,.05);
  color: var(--text-2);
  border-color: var(--border);
}

/* ---------- Section Headers ---------- */
.section-header { margin-bottom: 56px; }
.section-label {
  font-family: var(--mono);
  font-size: .8rem;
  letter-spacing: .12em;
  color: var(--crimson-light);
  text-transform: uppercase;
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.section-label::before {
  content: '';
  display: inline-block;
  width: 24px;
  height: 2px;
  background: var(--crimson);
}
.section-title {
  font-size: clamp(1.8rem, 3vw, 2.6rem);
  font-weight: 700;
  letter-spacing: -.02em;
  line-height: 1.2;
}
.section-sub {
  margin-top: 12px;
  color: var(--text-2);
  font-size: 1.05rem;
  max-width: 580px;
}

/* ================================================
   NAVIGATION
   ================================================ */
#navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: var(--bg-nav);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--t3) var(--ease), box-shadow var(--t3) var(--ease);
}
#navbar.scrolled {
  border-color: var(--border);
  box-shadow: 0 2px 20px rgba(15,23,42,.08);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}
.nav-logo {
  font-family: var(--mono);
  font-size: .95rem;
  color: var(--text);
  font-weight: 600;
  letter-spacing: -.01em;
}
.nav-logo span { color: var(--crimson-light); }
.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
}
.nav-links a {
  color: var(--text-2);
  font-size: .88rem;
  font-weight: 500;
  padding: 6px 12px;
  border-radius: 6px;
  transition: color var(--t3), background var(--t3);
  letter-spacing: .01em;
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--text);
  background: rgba(255,255,255,.06);
}
.nav-links a.nav-cta {
  background: var(--crimson);
  color: #fff;
  padding: 6px 16px;
  border-radius: 6px;
}
.nav-links a.nav-cta:hover { background: var(--crimson-light); }

/* Hamburger */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-2);
  border-radius: 2px;
  transition: transform var(--t3) var(--ease), opacity var(--t3);
}
.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); }

/* ================================================
   HERO
   ================================================ */
#hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  background: linear-gradient(135deg, #f0f5ff 0%, #f8fafc 60%, #eef2ff 100%);
}
#particle-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 20% 50%, rgba(37,99,235,.07) 0%, transparent 60%),
              radial-gradient(ellipse at 80% 20%, rgba(37,99,235,.04) 0%, transparent 50%);
  z-index: 1;
}
.hero-content {
  position: relative;
  z-index: 2;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  padding-top: 80px;
}
.hero-eyebrow {
  font-family: var(--mono);
  font-size: .82rem;
  color: var(--crimson-light);
  letter-spacing: .14em;
  text-transform: uppercase;
  margin-bottom: 16px;
  opacity: 0;
  animation: fadeUp .8s var(--ease) .2s forwards;
}
.hero-eyebrow::before { content: '> '; color: var(--text-3); }
.hero-name {
  font-size: clamp(2.8rem, 7vw, 5.5rem);
  font-weight: 800;
  letter-spacing: -.04em;
  line-height: 1.05;
  margin-bottom: 6px;
  opacity: 0;
  animation: fadeUp .8s var(--ease) .4s forwards;
}
.hero-name .accent { color: var(--crimson-light); }
.hero-title {
  font-size: clamp(1rem, 2.5vw, 1.45rem);
  color: var(--text-2);
  font-weight: 500;
  margin-bottom: 28px;
  opacity: 0;
  animation: fadeUp .8s var(--ease) .6s forwards;
}
.hero-desc {
  max-width: 560px;
  color: var(--text-2);
  font-size: 1.05rem;
  line-height: 1.8;
  margin-bottom: 40px;
  opacity: 0;
  animation: fadeUp .8s var(--ease) .8s forwards;
}
.hero-btns {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  opacity: 0;
  animation: fadeUp .8s var(--ease) 1s forwards;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 26px;
  border-radius: var(--radius);
  font-size: .92rem;
  font-weight: 600;
  transition: all var(--t3) var(--ease);
  cursor: pointer;
  border: none;
}
.btn-primary {
  background: var(--crimson);
  color: #fff;
}
.btn-primary:hover {
  background: var(--crimson-light);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: var(--shadow-c);
}
.btn-outline {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-outline:hover {
  background: rgba(255,255,255,.05);
  border-color: var(--crimson);
  color: var(--text);
  transform: translateY(-2px);
}
.hero-stats {
  display: flex;
  gap: 48px;
  margin-top: 64px;
  opacity: 0;
  animation: fadeUp .8s var(--ease) 1.2s forwards;
}
.hero-stat-num {
  font-size: 2rem;
  font-weight: 800;
  color: var(--crimson-light);
  line-height: 1;
}
.hero-stat-label {
  font-size: .78rem;
  color: var(--text-2);
  letter-spacing: .04em;
  margin-top: 4px;
}
.hero-scroll {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--text-3);
  font-size: .75rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  animation: bounce 2s infinite;
}
.hero-scroll::after {
  content: '';
  display: block;
  width: 1px;
  height: 48px;
  background: linear-gradient(to bottom, var(--crimson-light), transparent);
}

/* ================================================
   CARDS
   ================================================ */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: transform var(--t3) var(--ease), box-shadow var(--t3) var(--ease), border-color var(--t3) var(--ease);
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-c);
  border-color: var(--border-a);
}
.card-icon {
  width: 44px;
  height: 44px;
  background: var(--crimson-subtle);
  border: 1px solid var(--border-a);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  margin-bottom: 18px;
}
.card-title { font-size: 1.05rem; font-weight: 700; margin-bottom: 8px; }
.card-desc { color: var(--text-2); font-size: .92rem; line-height: 1.7; }

/* ================================================
   PUBLICATION ITEMS
   ================================================ */
.pub-list { display: flex; flex-direction: column; gap: 2px; }
.pub-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 24px;
  transition: border-color var(--t3), box-shadow var(--t3);
  cursor: default;
}
.pub-item:hover {
  border-color: var(--border-a);
  box-shadow: inset 0 0 0 1px rgba(37,99,235,.08);
}
.pub-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 8px;
}
.pub-year {
  font-family: var(--mono);
  font-size: .78rem;
  color: var(--text-3);
}
.pub-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  line-height: 1.4;
  margin-bottom: 6px;
}
.pub-title a { color: var(--text); }
.pub-title a:hover { color: var(--crimson-light); }
.pub-authors {
  font-size: .87rem;
  color: var(--text-2);
  margin-bottom: 4px;
}
.pub-authors .me { color: var(--text); font-weight: 600; }
.pub-venue {
  font-size: .85rem;
  color: var(--text-3);
  font-style: italic;
}
.pub-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 12px;
  flex-wrap: wrap;
}
.pub-link {
  font-size: .82rem;
  color: var(--crimson-light);
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 10px;
  border: 1px solid var(--border-a);
  border-radius: 4px;
  transition: background var(--t3);
}
.pub-link:hover { background: var(--crimson-subtle); }
.pub-cite {
  font-family: var(--mono);
  font-size: .78rem;
  color: var(--text-3);
  margin-left: auto;
}

/* Publication filter bar */
.pub-filter {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}
.pub-search {
  flex: 1;
  min-width: 240px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text);
  font-family: var(--font);
  font-size: .9rem;
  padding: 10px 16px;
  border-radius: var(--radius);
  outline: none;
  transition: border-color var(--t3);
}
.pub-search::placeholder { color: var(--text-3); }
.pub-search:focus { border-color: var(--crimson); }
.filter-btn {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-2);
  font-size: .82rem;
  font-weight: 600;
  padding: 9px 16px;
  border-radius: var(--radius);
  cursor: pointer;
  transition: all var(--t3);
}
.filter-btn:hover,
.filter-btn.active {
  background: var(--crimson-subtle);
  border-color: var(--border-a);
  color: var(--crimson-light);
}

/* ================================================
   TIMELINE
   ================================================ */
.timeline { position: relative; padding-left: 28px; }
.timeline::before {
  content: '';
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 0;
  width: 1px;
  background: linear-gradient(to bottom, var(--crimson), transparent);
}
.timeline-item {
  position: relative;
  margin-bottom: 36px;
  opacity: 0;
  transform: translateX(-16px);
  transition: opacity .6s var(--ease), transform .6s var(--ease);
}
.timeline-item.visible { opacity: 1; transform: none; }
.timeline-item::before {
  content: '';
  position: absolute;
  left: -25px;
  top: 8px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--crimson);
  box-shadow: 0 0 10px var(--crimson-glow);
}
.timeline-year {
  font-family: var(--mono);
  font-size: .78rem;
  color: var(--crimson-light);
  letter-spacing: .06em;
  margin-bottom: 4px;
}
.timeline-title { font-size: 1rem; font-weight: 700; margin-bottom: 2px; }
.timeline-sub { font-size: .88rem; color: var(--text-2); }
.timeline-desc { font-size: .88rem; color: var(--text-2); margin-top: 6px; }

/* ================================================
   SKILLS
   ================================================ */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
}
.skill-group {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 22px;
  transition: border-color var(--t3);
}
.skill-group:hover { border-color: var(--border-a); }
.skill-group-title {
  font-size: .82rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--crimson-light);
  margin-bottom: 14px;
  font-family: var(--mono);
}
.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.skill-tag {
  background: rgba(255,255,255,.04);
  border: 1px solid var(--border);
  color: var(--text-2);
  font-size: .82rem;
  padding: 4px 12px;
  border-radius: 4px;
  transition: all var(--t3);
}
.skill-tag:hover {
  background: var(--crimson-subtle);
  border-color: var(--border-a);
  color: var(--crimson-light);
}

/* ================================================
   RESEARCH CARDS
   ================================================ */
.research-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
}
.research-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 30px;
  transition: all var(--t3) var(--ease);
  position: relative;
  overflow: hidden;
}
.research-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--crimson), transparent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--t5) var(--ease);
}
.research-card:hover { border-color: var(--border-a); transform: translateY(-4px); box-shadow: var(--shadow-c); }
.research-card:hover::before { transform: scaleX(1); }
.research-card-num {
  font-family: var(--mono);
  font-size: .72rem;
  color: var(--text-3);
  margin-bottom: 16px;
}
.research-card-title { font-size: 1.1rem; font-weight: 700; margin-bottom: 10px; }
.research-card-body { font-size: .91rem; color: var(--text-2); line-height: 1.75; }
.research-card-tags { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 18px; }

/* ================================================
   TERMINAL BLOCK (Code-editor style)
   ================================================ */
.terminal {
  background: var(--bg-code);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  font-family: var(--mono);
}
.terminal-header {
  background: #161b22;
  padding: 10px 16px;
  display: flex;
  align-items: center;
  gap: 8px;
  border-bottom: 1px solid var(--border);
}
.terminal-dot {
  width: 12px; height: 12px;
  border-radius: 50%;
}
.terminal-dot:nth-child(1) { background: #ff5f57; }
.terminal-dot:nth-child(2) { background: #ffbd2e; }
.terminal-dot:nth-child(3) { background: #28c841; }
.terminal-filename {
  margin-left: 8px;
  font-size: .78rem;
  color: var(--text-3);
}
.terminal-body {
  padding: 22px 26px;
  font-size: .88rem;
  line-height: 2;
  color: #8b949e;
}
.terminal-body .t-key { color: #79c0ff; }
.terminal-body .t-val { color: #a5d6ff; }
.terminal-body .t-str { color: #a8d8a8; }
.terminal-body .t-num { color: #ff9900; }
.terminal-body .t-comment { color: #444d56; }
.terminal-body .t-crimson { color: var(--crimson-light); }

/* ================================================
   CONTACT
   ================================================ */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: start;
}
.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 20px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color var(--t3);
}
.contact-item:hover { border-color: var(--border-a); }
.contact-icon {
  width: 40px; height: 40px;
  min-width: 40px;
  background: var(--crimson-subtle);
  border: 1px solid var(--border-a);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
}
.contact-info { flex: 1; }
.contact-label { font-size: .78rem; color: var(--text-3); text-transform: uppercase; letter-spacing: .08em; margin-bottom: 2px; }
.contact-val { font-size: .95rem; color: var(--text); font-weight: 500; }

/* ================================================
   AWARDS / HIGHLIGHTS
   ================================================ */
.award-item {
  display: flex;
  align-items: flex-start;
  gap: 18px;
  padding: 22px 24px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-left: 3px solid var(--crimson);
  border-radius: var(--radius);
  margin-bottom: 14px;
  transition: box-shadow var(--t3);
}
.award-item:hover { box-shadow: var(--shadow-c); }
.award-year {
  font-family: var(--mono);
  font-size: .8rem;
  color: var(--crimson-light);
  min-width: 44px;
  padding-top: 3px;
}
.award-title { font-size: .97rem; font-weight: 700; margin-bottom: 4px; }
.award-desc { font-size: .87rem; color: var(--text-2); }

/* ================================================
   FOOTER
   ================================================ */
footer {
  background: var(--bg-2);
  border-top: 1px solid var(--border);
  padding: 48px 0 32px;
  color: var(--text);
}
.footer-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}
.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 32px;
  flex-wrap: wrap;
  margin-bottom: 36px;
  padding-bottom: 36px;
  border-bottom: 1px solid var(--border);
}
.footer-brand { max-width: 320px; }
.footer-brand-name {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
}
.footer-brand-name span { color: var(--crimson-light); }
.footer-tagline { font-size: .88rem; color: var(--text-2); }
.footer-links-group { display: flex; gap: 48px; flex-wrap: wrap; }
.footer-links-col h4 {
  font-size: .78rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--text-3);
  margin-bottom: 14px;
  font-family: var(--mono);
}
.footer-links-col ul { list-style: none; }
.footer-links-col li { margin-bottom: 8px; }
.footer-links-col a { color: var(--text-2); font-size: .88rem; }
.footer-links-col a:hover { color: var(--text); }
.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}
.footer-copy { font-size: .82rem; color: var(--text-3); }
.footer-socials { display: flex; gap: 14px; }
.footer-social-link {
  width: 34px; height: 34px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-2);
  font-size: .85rem;
  transition: all var(--t3);
}
.footer-social-link:hover {
  background: var(--crimson-subtle);
  border-color: var(--border-a);
  color: var(--crimson-light);
}

/* ================================================
   PAGE HERO (inner pages)
   ================================================ */
.page-hero {
  padding: 140px 0 80px;
  position: relative;
  overflow: hidden;
}
.page-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 30% 40%, rgba(37,99,235,.05) 0%, transparent 60%);
  pointer-events: none;
}
.page-hero-label {
  font-family: var(--mono);
  font-size: .8rem;
  color: var(--crimson-light);
  letter-spacing: .12em;
  text-transform: uppercase;
  margin-bottom: 12px;
}
.page-hero-title {
  font-size: clamp(2rem, 5vw, 3.8rem);
  font-weight: 800;
  letter-spacing: -.03em;
  line-height: 1.1;
  margin-bottom: 14px;
}
.page-hero-sub {
  font-size: 1.1rem;
  color: var(--text-2);
  max-width: 580px;
  line-height: 1.7;
}

/* Grid 2 col */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }

/* Reveal animation */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity .7s var(--ease), transform .7s var(--ease);
}
.reveal.visible { opacity: 1; transform: none; }

/* ================================================
   ANIMATIONS
   ================================================ */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: none; }
}
@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50%       { transform: translateX(-50%) translateY(-8px); }
}
@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 0 var(--crimson-glow); }
  50%       { box-shadow: 0 0 0 8px transparent; }
}
@keyframes blink {
  50% { opacity: 0; }
}

/* Typing cursor */
.cursor::after {
  content: '|';
  color: var(--crimson-light);
  animation: blink 1s step-end infinite;
}

/* ================================================
   RESPONSIVE
   ================================================ */
@media (max-width: 900px) {
  .contact-grid { grid-template-columns: 1fr; }
  .grid-2 { grid-template-columns: 1fr; }
  .grid-3 { grid-template-columns: 1fr 1fr; }
  .hero-stats { gap: 32px; }
  .footer-top { flex-direction: column; }
}
@media (max-width: 720px) {
  .nav-links { display: none; flex-direction: column; position: absolute; top: 64px; left: 0; right: 0; background: var(--bg-nav); backdrop-filter: blur(16px); border-bottom: 1px solid var(--border); padding: 16px 24px; gap: 4px; }
  .nav-links.open { display: flex; }
  .nav-toggle { display: flex; }
  .research-grid { grid-template-columns: 1fr; }
  .skills-grid { grid-template-columns: 1fr 1fr; }
  .grid-3 { grid-template-columns: 1fr; }
  .hero-stats { flex-wrap: wrap; gap: 24px; }
  .pub-filter { flex-direction: column; align-items: stretch; }
  .pub-cite { margin-left: 0; }
  .footer-links-group { gap: 32px; }
  .section { padding: 72px 0; }
}
@media (max-width: 480px) {
  .skills-grid { grid-template-columns: 1fr; }
  .hero-btns { flex-direction: column; }
  .hero-btns .btn { text-align: center; justify-content: center; }
}