@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

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

:root {
  --accent: #0051ff;
  --accent-hover: #003ecc;
  --accent-light: #eff6ff;
  --text-primary: #0f0f0f;
  --text-secondary: #4b5563;
  --text-tertiary: #9ca3af;
  --bg: #ffffff;
  --bg-secondary: #f9fafb;
  --border: #e5e7eb;
  --tag-bg: #f3f4f6;
  --tag-text: #374151;
  --radius: 8px;
  --max-w: 960px;
  --card-bg: rgba(255, 255, 255, 0.72);
  --card-bg-secondary: rgba(249, 250, 251, 0.72);
  color-scheme: light;
}

[data-theme="dark"] {
  --accent: #4d84ff;
  --accent-hover: #6b9bff;
  --accent-light: #0d1f40;
  --text-primary: #efefef;
  --text-secondary: #a0a0aa;
  --text-tertiary: #606068;
  --bg: #0c0c0c;
  --bg-secondary: #161616;
  --border: #242424;
  --tag-bg: #1c1c1c;
  --tag-text: #c4c4cc;
  --card-bg: rgba(18, 18, 20, 0.72);
  --card-bg-secondary: rgba(22, 22, 26, 0.72);
  color-scheme: dark;
}

html {
  scroll-behavior: smooth;
  transition: background-color 0.25s ease;
}

/* ─── SCROLL REVEAL ──────────────────────────────────────── */

.will-reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}

.will-reveal.is-revealed {
  opacity: 1;
  transform: translateY(0);
}

/* ─── HERO ENTRANCE ──────────────────────────────────────── */

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(18px); }
  to   { opacity: 1; transform: translateY(0); }
}

.hero-badge    { animation: fadeUp 0.5s ease 0.05s both; }

.hero-name     { animation: fadeUp 0.55s ease 0.12s both; }

.hero-subtitle { animation: fadeUp 0.55s ease 0.2s both; }

.hero-bio      { animation: fadeUp 0.55s ease 0.28s both; }

.hero-actions  { animation: fadeUp 0.55s ease 0.36s both; }

.hero-card     { animation: fadeUp 0.55s ease 0.2s both; }

/* ─── smooth theme transition on key surfaces ────────────── */

body,
.header,
.hero-card,
.research-card,
.edu-card,
.vol-card,
.project-card,
.repo-card,
.contact-quote,
.tag,
.pub-icon,
.pub-doi,
.btn-resume,
.btn-outline {
  transition:
    background-color 0.25s ease,
    border-color 0.25s ease,
    color 0.15s ease;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 15px;
  line-height: 1.6;
  color: var(--text-primary);
  background: linear-gradient(135deg, #ffffff 0%, #e8f0ff 50%, #f0fff8 100%) fixed;
  -webkit-font-smoothing: antialiased;
}

[data-theme="dark"] body {
  background: linear-gradient(135deg, #0c0c0c 0%, #0d1a33 50%, #001a12 100%) fixed;
}

.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

/* ─── HEADER ─────────────────────────────────────────────── */

.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.75);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.logo {
  font-size: 20px;
  font-weight: 800;
  color: var(--text-primary);
  text-decoration: none;
  letter-spacing: -0.5px;
}

.logo span { color: #10b981; }

.nav {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.nav a {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-decoration: none;
  color: var(--text-secondary);
  text-transform: uppercase;
  transition: color 0.15s;
  position: relative;
  padding-bottom: 2px;
}

.nav a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1.5px;
  background: var(--accent);
  border-radius: 2px;
  transition: width 0.22s ease;
}

.nav a:hover { color: var(--text-primary); }

.nav a:hover::after { width: 100%; }

.btn-resume {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 7px 16px;
  border: 1.5px solid var(--text-primary);
  background: transparent;
  color: var(--text-primary);
  border-radius: 4px;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.15s;
}

.btn-resume:hover {
  background: var(--text-primary);
  color: #fff;
}

/* ─── HERO ───────────────────────────────────────────────── */

.hero { padding: 72px 0 80px; }

.hero-inner {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 48px;
  align-items: start;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 20px;
}

.badge-dot {
  width: 8px;
  height: 8px;
  background: #10b981;
  border-radius: 50%;
  flex-shrink: 0;
}

.hero-name {
  font-size: 54px;
  font-weight: 800;
  letter-spacing: -2px;
  line-height: 1.05;
  margin-bottom: 14px;
}

.hero-name-gradient {
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 17px;
  font-weight: 500;
  color: var(--accent);
  margin-bottom: 20px;
}

.hero-bio {
  font-size: 15px;
  line-height: 1.75;
  color: var(--text-secondary);
  max-width: 500px;
  margin-bottom: 32px;
}

.hero-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

/* Buttons */

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.15s;
}

.btn-primary:hover { background: var(--accent-hover); }

.btn-primary:active { transform: scale(0.97); }

.btn-outline:active { transform: scale(0.97); }

.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 16px;
  background: transparent;
  color: var(--text-primary);
  border: 1.5px solid var(--border);
  border-radius: 6px;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  text-decoration: none;
  transition: border-color 0.15s;
}

.btn-outline:hover { border-color: var(--text-primary); }

/* Hero info card */

.hero-card {
  background: var(--card-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.hero-avatar-wrap {
  display: flex;
  justify-content: center;
  padding: 24px 20px 16px;
  border-bottom: 1px solid var(--border);
}

.hero-avatar {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--border);
}

.hero-card-body { padding: 20px 20px 0; }

.contact-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 0;
  font-size: 13.5px;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border);
}

.contact-item:last-child { border-bottom: none; }

.contact-icon {
  width: 18px;
  flex-shrink: 0;
  color: var(--text-tertiary);
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--border);
}

.stat {
  padding: 16px 12px;
  text-align: center;
}

.stat:not(:last-child) { border-right: 1px solid var(--border); }

.stat-label {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  margin-bottom: 4px;
}

.stat-value {
  font-size: 28px;
  font-weight: 800;
  color: var(--accent);
  letter-spacing: -0.5px;
  line-height: 1;
}

/* ─── SECTION COMMON ─────────────────────────────────────── */

.section {
  padding: 72px 0;
  border-top: 1px solid var(--border);
}

.section-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  margin-bottom: 6px;
}

.section-title {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.5px;
  color: var(--text-primary);
  margin-bottom: 28px;
}

/* Tags */

.tag {
  display: inline-block;
  padding: 3px 9px;
  background: var(--tag-bg);
  color: var(--tag-text);
  border-radius: 4px;
  font-size: 12px;
  font-weight: 500;
  transition: background-color 0.15s, color 0.15s;
  cursor: default;
}

.tag:hover {
  background: var(--accent-light);
  color: var(--accent);
}

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

/* ─── RESEARCH ───────────────────────────────────────────── */

.research-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-bottom: 36px;
}

.research-card {
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius);
  padding: 18px 20px;
  background: var(--card-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.research-card:hover {
  box-shadow: 0 6px 20px rgba(0,0,0,0.07);
  transform: translateY(-2px);
}

.research-card-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 8px;
  margin-bottom: 6px;
}

.research-role {
  font-size: 12px;
  color: var(--text-tertiary);
  font-weight: 500;
}

.research-period {
  font-size: 11.5px;
  color: var(--text-tertiary);
  white-space: nowrap;
  flex-shrink: 0;
}

.research-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
  line-height: 1.4;
}

.research-desc {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 12px;
}

.pubs-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0;
}

.pub-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
}

.pub-item:first-of-type { border-top: 1px solid var(--border); }

.pub-icon {
  width: 34px;
  height: 34px;
  border: 1px solid var(--border);
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 15px;
  color: var(--text-tertiary);
  background: var(--card-bg-secondary);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.pub-content { flex: 1; }

.pub-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.pub-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
}

.pub-conference {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 8px;
  background: var(--accent-light);
  color: var(--accent);
  border-radius: 4px;
  font-size: 11px;
  font-weight: 700;
}

.pub-date {
  font-size: 12px;
  color: var(--text-tertiary);
  margin-left: auto;
}

.pub-conference-link {
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: opacity 0.15s;
}

.pub-conference-link:hover { opacity: 0.75; }

.pub-doi {
  font-size: 11px;
  font-weight: 500;
  color: var(--text-tertiary);
  text-decoration: none;
  font-family: monospace;
  border: 1px solid var(--border);
  padding: 2px 7px;
  border-radius: 4px;
  transition: color 0.15s, border-color 0.15s;
}

.pub-doi:hover {
  color: var(--accent);
  border-color: var(--accent);
}

/* ─── PROJECTS ───────────────────────────────────────────── */

.projects-featured {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-bottom: 14px;
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}

.project-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  background: var(--card-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: box-shadow 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.project-card:hover {
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.09);
  border-color: #d1d5db;
  transform: translateY(-3px);
}

.project-card-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 10px;
}

.project-icon {
  width: 40px;
  height: 40px;
  background: var(--tag-bg);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  line-height: 1;
}

.featured-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 11px;
  font-weight: 600;
  color: #92400e;
  background: #fef3c7;
  padding: 3px 8px;
  border-radius: 4px;
}

.project-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 5px;
}

.project-desc {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.55;
  margin-bottom: 12px;
}

.project-links {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-top: 12px;
}

.project-link {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.15s;
}

.project-link:hover { color: var(--accent); }

.project-link-live {
  color: var(--accent);
}

.project-link-live:hover { opacity: 0.75; }

/* ─── SKILLS ─────────────────────────────────────────────── */

.skills-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 20px;
}

.skill-group-title {
  font-size: 12px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
}

.skill-tags {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

/* ─── REPOS ──────────────────────────────────────────────── */

.repos-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 18px;
}

.repos-count { font-size: 14px; color: var(--text-secondary); }

.repos-viewall {
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: opacity 0.15s;
}

.repos-viewall:hover { opacity: 0.75; }

.repos-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}

.repo-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  background: var(--card-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  display: flex;
  flex-direction: column;
  transition: box-shadow 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.repo-card:hover {
  box-shadow: 0 8px 24px rgba(0,0,0,0.09);
  border-color: #d1d5db;
  transform: translateY(-3px);
}

.repo-name {
  font-size: 14px;
  font-weight: 700;
  color: var(--accent);
  text-decoration: none;
  display: block;
  margin-bottom: 6px;
  transition: opacity 0.15s;
}

.repo-name:hover { opacity: 0.75; }

.repo-desc {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.55;
  flex: 1;
  margin-bottom: 14px;
}

.repo-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  color: var(--text-tertiary);
}

.repo-lang {
  display: flex;
  align-items: center;
  gap: 5px;
}

.lang-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #3b82f6;
  flex-shrink: 0;
}

.repo-stat {
  display: flex;
  align-items: center;
  gap: 3px;
}

/* ─── CONTACT ────────────────────────────────────────────── */

.contact { padding: 72px 0; border-top: 1px solid var(--border); }

.contact-body { max-width: 640px; }

.contact-quote {
  background: var(--card-bg-secondary);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-radius: var(--radius);
  padding: 22px 24px 22px 40px;
  margin: 20px 0 28px;
  position: relative;
}

.quote-mark {
  font-size: 52px;
  color: var(--border);
  line-height: 1;
  position: absolute;
  top: 4px;
  left: 14px;
  font-family: Georgia, serif;
  user-select: none;
}

.contact-quote p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.75;
}

.contact-actions { display: flex; gap: 10px; flex-wrap: wrap; }

/* ─── FOOTER ─────────────────────────────────────────────── */

.footer {
  border-top: 1px solid var(--border);
  padding: 22px 0;
}

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

.footer-copy { font-size: 13px; color: var(--text-tertiary); }

.footer-socials { display: flex; gap: 14px; }

.footer-social {
  color: var(--text-tertiary);
  text-decoration: none;
  display: flex;
  align-items: center;
  transition: color 0.15s;
}

.footer-social:hover { color: var(--text-primary); }

/* ─── EDUCATION ──────────────────────────────────────────── */

.edu-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.edu-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  background: var(--card-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: box-shadow 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.edu-card:hover {
  box-shadow: 0 6px 20px rgba(0,0,0,0.07);
  transform: translateY(-2px);
}

.edu-card-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 8px;
  margin-bottom: 6px;
}

.edu-institution {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-primary);
}

.edu-period {
  font-size: 11.5px;
  color: var(--text-tertiary);
  white-space: nowrap;
  flex-shrink: 0;
}

.edu-degree {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 10px;
  line-height: 1.5;
}

.edu-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.edu-location {
  font-size: 12px;
  color: var(--text-tertiary);
}

.edu-grade {
  font-size: 12px;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-light);
  padding: 2px 8px;
  border-radius: 4px;
}

/* ─── VOLUNTEERING ───────────────────────────────────────── */

.vol-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.vol-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  background: var(--card-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: box-shadow 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.vol-card:hover {
  box-shadow: 0 6px 20px rgba(0,0,0,0.07);
  transform: translateY(-2px);
}

.vol-card-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 8px;
  margin-bottom: 14px;
}

.vol-event {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 3px;
}

.vol-role {
  font-size: 12px;
  color: var(--accent);
  font-weight: 600;
}

.vol-period {
  font-size: 11.5px;
  color: var(--text-tertiary);
  white-space: nowrap;
  flex-shrink: 0;
}

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

.vol-points li {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
  padding-left: 14px;
  position: relative;
}

.vol-points li::before {
  content: '·';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
}

/* ─── SKELETON LOADER ────────────────────────────────────── */

@keyframes shimmer {
  0%   { background-position: -600px 0; }
  100% { background-position:  600px 0; }
}

.skeleton {
  border-radius: 4px;
  background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
  background-size: 600px 100%;
  animation: shimmer 1.4s infinite linear;
}

.skeleton-title  { height: 16px; width: 55%; margin-bottom: 10px; }

.skeleton-text   { height: 13px; width: 100%; margin-bottom: 6px; }

.skeleton-text.short { width: 70%; margin-bottom: 16px; }

.skeleton-meta   { height: 12px; width: 80%; }

.repos-fallback,
.repos-cache-note {
  font-size: 12px;
  color: var(--text-tertiary);
  margin-left: 4px;
}

/* ─── THEME TOGGLE ───────────────────────────────────────── */

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  background: none;
  border: 1.5px solid var(--border);
  border-radius: 6px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s, background 0.15s;
  flex-shrink: 0;
}

.theme-toggle:hover {
  border-color: var(--text-primary);
  color: var(--text-primary);
  background: var(--tag-bg);
}

/* ─── DARK MODE OVERRIDES ────────────────────────────────── */

/* header glass */

[data-theme="dark"] .header {
  background: rgba(12, 12, 12, 0.75);
}

/* featured badge (amber) */

[data-theme="dark"] .featured-badge {
  background: #2a1f00;
  color: #d4a560;
}

/* pub conference badge light bg */

[data-theme="dark"] .pub-conference {
  background: var(--accent-light);
}

/* skeleton shimmer */

[data-theme="dark"] .skeleton {
  background: linear-gradient(90deg, #1a1a1a 25%, #262626 50%, #1a1a1a 75%);
  background-size: 600px 100%;
}

/* ─── HEADER RIGHT ───────────────────────────────────────── */

.header-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* ─── RESPONSIVE — 1024px (tablet landscape) ─────────────── */

@media (max-width: 1024px) {
  :root { --max-w: 100%; }

  .skills-grid { grid-template-columns: repeat(3, 1fr); gap: 16px; }
  .repos-grid { grid-template-columns: repeat(2, 1fr); }
}

/* ─── RESPONSIVE — 768px (tablet portrait) ───────────────── */

@media (max-width: 768px) {
  /* Header */
  .nav { display: none; }

  /* Section spacing */
  .section { padding: 52px 0; }
  .hero { padding: 48px 0 56px; }
  .contact { padding: 52px 0; }
  .section-title { font-size: 24px; margin-bottom: 20px; }

  /* Hero */
  .hero-inner { grid-template-columns: 1fr; gap: 32px; }
  .hero-name { font-size: 40px; letter-spacing: -1.5px; }
  .hero-subtitle { font-size: 15px; }
  .hero-bio { font-size: 14px; }

  /* Grids → single column */
  .edu-grid { grid-template-columns: 1fr; }
  .research-grid { grid-template-columns: 1fr; }
  .vol-grid { grid-template-columns: 1fr; }
  .projects-featured { grid-template-columns: 1fr; }
  .projects-grid { grid-template-columns: repeat(2, 1fr); }
  .repos-grid { grid-template-columns: 1fr; }

  /* Skills */
  .skills-grid { grid-template-columns: repeat(3, 1fr); gap: 14px; }

  /* Footer */
  .footer-inner { flex-direction: column; gap: 12px; text-align: center; }

  /* Contact */
  .contact-quote { padding: 20px 20px 20px 36px; }
}

/* ─── RESPONSIVE — 640px (large phone) ───────────────────── */

@media (max-width: 640px) {
  .container { padding: 0 16px; }

  .hero-name { font-size: 34px; letter-spacing: -1px; }
  .hero-subtitle { font-size: 14px; }
  .hero-actions { gap: 8px; }
  .btn-primary, .btn-outline { font-size: 13px; padding: 9px 14px; }

  .stat-value { font-size: 24px; }
  .stat-label { font-size: 9px; }
  .stat { padding: 12px 8px; }

  .research-card { padding: 16px; }
  .research-card-head { flex-direction: column; gap: 2px; }
  .research-period { font-size: 11px; }

  .projects-grid { grid-template-columns: 1fr; }
  .skills-grid { grid-template-columns: repeat(2, 1fr); }

  .repos-header { flex-direction: column; align-items: flex-start; gap: 6px; }

  .pub-item { flex-direction: column; gap: 10px; }
  .pub-date { margin-left: 0; }

  .vol-card-head { flex-direction: column; gap: 4px; }

  .edu-card-head { flex-direction: column; gap: 2px; }
  .edu-period { font-size: 11px; }
}

/* ─── RESPONSIVE — 480px (phone) ─────────────────────────── */

@media (max-width: 480px) {
  .hero { padding: 36px 0 44px; }
  .section { padding: 44px 0; }
  .hero-name { font-size: 30px; }
  .section-title { font-size: 22px; }

  .hero-badge { font-size: 12px; }
  .hero-bio { font-size: 13.5px; }

  .skills-grid { grid-template-columns: repeat(2, 1fr); }

  .hero-card-body { padding: 16px 16px 0; }
  .contact-item { font-size: 13px; }

  .project-card { padding: 14px; }
  .edu-card { padding: 14px; }
  .vol-card { padding: 14px; }
  .repo-card { padding: 14px; }

  .contact-actions { flex-direction: column; }
  .contact-actions .btn-primary,
  .contact-actions .btn-outline { width: 100%; justify-content: center; }
}

/* ─── RESPONSIVE — 360px (small phone) ───────────────────── */

@media (max-width: 360px) {
  .hero-name { font-size: 26px; }
  .skills-grid { grid-template-columns: 1fr 1fr; }
  .hero-stats { grid-template-columns: repeat(3, 1fr); }
  .stat-value { font-size: 20px; }
}