:root {
  --color-bg: #faf9f7;
  --color-surface: #fff;
  --color-text: #1a1a1a;
  --color-text-muted: #4a4a4a;
  --color-accent: #0d47a1;
  --color-accent-light: #1565c0;
  --color-border: #e0ddd9;
  --font-serif: 'Cormorant Garamond', Georgia, serif;
  --font-sans: 'Source Sans 3', -apple-system, BlinkMacSystemFont, sans-serif;
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --radius: 6px;
  --shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
  --transition: 0.2s ease;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
}

/* Keyboard accessibility */
.skip-link {
  position: absolute;
  left: var(--space-lg);
  top: var(--space-lg);
  z-index: 1000;
  background: var(--color-surface);
  color: var(--color-text);
  border: 2px solid var(--color-accent);
  border-radius: var(--radius);
  padding: var(--space-sm) var(--space-md);
  text-decoration: none;
  transform: translateY(-200%);
  transition: transform var(--transition);
}
.skip-link:focus,
.skip-link:focus-visible {
  transform: translateY(0);
}

:where(a, button, input, select, textarea, [tabindex]:not([tabindex="-1"])):focus-visible {
  outline: 3px solid rgba(13, 71, 161, 0.45);
  outline-offset: 3px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 249, 247, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}
.site-header.is-scrolled { box-shadow: var(--shadow); }

.nav {
  max-width: 960px;
  margin: 0 auto;
  padding: var(--space-md) var(--space-lg);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.5rem;
  color: var(--color-accent);
  text-decoration: none;
  letter-spacing: 0.02em;
}
.nav-links {
  display: flex;
  gap: var(--space-lg);
  list-style: none;
  margin: 0;
  padding: 0;
}
.nav-links a {
  color: var(--color-text-muted);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  transition: color var(--transition);
}
.nav-links a:hover { color: var(--color-accent); }
body.page-about .nav-links a[href="index.html"],
body.page-projects .nav-links a[href="projects.html"],
body.page-hackathons .nav-links a[href="hackathons.html"],
body.page-experience .nav-links a[href="experience.html"],
body.page-publications .nav-links a[href="publications.html"],
body.page-cv .nav-links a[href="cv.html"] {
  color: var(--color-accent);
  font-weight: 600;
}
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-sm);
}
.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--color-text);
}

.hero {
  min-height: 85vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-2xl) var(--space-lg);
  background: linear-gradient(160deg, #e8eef5 0%, var(--color-bg) 50%, #f0eeeb 100%);
  border-bottom: 1px solid var(--color-border);
}
.hero-content { text-align: center; max-width: 640px; }
.hero-badge {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-accent);
  background: rgba(13, 71, 161, 0.1);
  padding: var(--space-xs) var(--space-md);
  border-radius: 999px;
  margin-bottom: var(--space-lg);
}
.hero-name {
  font-family: var(--font-serif);
  font-size: clamp(2.25rem, 6vw, 3.5rem);
  font-weight: 600;
  margin: 0 0 var(--space-sm);
  letter-spacing: 0.02em;
}
.hero-tagline {
  font-size: 1.2rem;
  color: var(--color-text);
  margin: 0 0 var(--space-xs);
  font-weight: 500;
}
.hero-subtitle, .hero-location {
  font-size: 1rem;
  color: var(--color-text-muted);
  margin: 0 0 var(--space-xs);
}
.hero-location { margin-bottom: var(--space-xl); }
.hero.hero-compact {
  min-height: 60vh;
  padding: var(--space-xl) var(--space-lg);
}
.hero.hero-compact .hero-content { max-width: 100%; }
.hero-cta {
  display: flex;
  gap: var(--space-md);
  justify-content: center;
  flex-wrap: wrap;
}

.highlights {
  padding: var(--space-lg) var(--space-lg);
  background: var(--color-text);
  color: rgba(255,255,255,0.9);
}
.highlights-inner {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-lg) var(--space-2xl);
  font-size: 0.95rem;
}
.highlight-item strong { color: #fff; }

.btn {
  display: inline-block;
  padding: var(--space-sm) var(--space-lg);
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  border-radius: var(--radius);
  transition: background var(--transition), color var(--transition);
}
.btn-primary {
  background: var(--color-accent);
  color: #fff;
}
.btn-primary:hover { background: var(--color-accent-light); }
.btn-secondary {
  background: transparent;
  color: var(--color-accent);
  border: 2px solid var(--color-accent);
}
.btn-secondary:hover { background: var(--color-accent); color: #fff; }

.section { padding: var(--space-2xl) var(--space-lg); }
.container { max-width: 800px; margin: 0 auto; }
.container-narrow { max-width: 640px; }
.page-head { padding-bottom: var(--space-lg); }
.page-title {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 600;
  margin: 0 0 var(--space-sm);
  color: var(--color-text);
  border-bottom: 2px solid var(--color-accent);
  padding-bottom: var(--space-sm);
  display: inline-block;
}
.section-title {
  font-family: var(--font-serif);
  font-size: 1.75rem;
  font-weight: 600;
  margin: 0 0 var(--space-xl);
  color: var(--color-text);
  border-bottom: 2px solid var(--color-accent);
  padding-bottom: var(--space-sm);
  display: inline-block;
}
.section-intro {
  color: var(--color-text-muted);
  font-size: 1rem;
  margin: 0 0 var(--space-xl);
}
.alt-bg { background: rgba(0,0,0,0.02); }

.updates-table-wrap { overflow-x: auto; }
.updates-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}
.updates-table td {
  padding: var(--space-sm) var(--space-md) var(--space-sm) 0;
  vertical-align: top;
  border-bottom: 1px solid var(--color-border);
}
.updates-table tr:last-child td { border-bottom: none; }
.updates-date {
  white-space: nowrap;
  color: var(--color-text-muted);
  font-size: 0.9rem;
  width: 6em;
}

.pub-list-numbered { list-style: decimal; padding-left: 1.5rem; }
.pub-list-numbered li { margin-bottom: var(--space-lg); }
.pub-list-numbered .pub-venue { margin-top: var(--space-xs); }

.project-cards-preview { grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.project-card h3 a {
  color: inherit;
  text-decoration: none;
}
.project-card h3 a:hover { color: var(--color-accent); }

.project-links {
  margin: 0 0 var(--space-md);
  font-size: 0.9rem;
}
.project-links a {
  color: var(--color-accent);
  text-decoration: none;
  margin-right: var(--space-lg);
}
.project-links a:hover { text-decoration: underline; }

.cv-download { margin-top: var(--space-lg); }

.about-content p { margin: 0 0 var(--space-md); }
.about-content .lead { font-size: 1.1rem; color: var(--color-text-muted); }
.about-content .highlight {
  background: rgba(13, 71, 161, 0.08);
  padding: var(--space-md);
  border-radius: var(--radius);
  border-left: 4px solid var(--color-accent);
}

.timeline {
  position: relative;
  padding-left: var(--space-xl);
}
.timeline::before {
  content: '';
  position: absolute;
  left: 6px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--color-border);
}
.timeline-item { position: relative; padding-bottom: var(--space-xl); }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-marker {
  position: absolute;
  left: calc(-1 * var(--space-xl) + 2px);
  top: 0.4em;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-accent);
  border: 3px solid var(--color-bg);
}
.timeline-content h3 { margin: 0 0 var(--space-xs); font-size: 1.15rem; }
.timeline-content .company { color: var(--color-accent); font-weight: 600; margin: 0 0 var(--space-xs); }
.timeline-content .meta { font-size: 0.9rem; color: var(--color-text-muted); margin: 0 0 var(--space-sm); }
.timeline-content .description { margin: 0; font-size: 0.95rem; color: var(--color-text-muted); }

.project-cards { display: grid; gap: var(--space-lg); }
.project-card {
  background: var(--color-surface);
  padding: var(--space-lg);
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition), border-color var(--transition);
}
.project-card:hover {
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  border-color: rgba(13, 71, 161, 0.2);
}
.project-card.featured {
  border-color: rgba(13, 71, 161, 0.35);
  padding: var(--space-xl);
}
.project-card.featured h3 { font-size: 1.25rem; }
.project-card h3 {
  margin: 0 0 var(--space-sm);
  font-size: 1.15rem;
  color: var(--color-accent);
}
.project-meta {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin: 0 0 var(--space-md);
}
.project-desc {
  margin: 0 0 var(--space-md);
  font-size: 0.95rem;
  color: var(--color-text-muted);
  line-height: 1.6;
}
.project-skills {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}
.project-skills li {
  background: rgba(13, 71, 161, 0.1);
  color: var(--color-accent);
  padding: var(--space-xs) var(--space-md);
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 500;
}

.cards { display: grid; gap: var(--space-lg); }
.card {
  background: var(--color-surface);
  padding: var(--space-lg);
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition);
}
.card:hover { box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08); }
.card h3 { margin: 0 0 var(--space-xs); font-size: 1.1rem; }
.card .company { color: var(--color-accent); font-weight: 600; margin: 0 0 var(--space-xs); }
.card .meta { font-size: 0.9rem; color: var(--color-text-muted); margin: 0 0 var(--space-xs); }
.card .coursework { font-size: 0.85rem; color: var(--color-text-muted); margin: 0; font-style: italic; }

.skills-grid { display: grid; gap: var(--space-xl); }
.skill-group h4 {
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-muted);
  margin: 0 0 var(--space-md);
}
.skill-tags {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}
.skill-tags li {
  background: var(--color-surface);
  padding: var(--space-xs) var(--space-md);
  border-radius: 999px;
  font-size: 0.9rem;
  border: 1px solid var(--color-border);
}
.skill-tags.lang-tags li span { opacity: 0.85; font-size: 0.85em; }

.pub-list, .cert-list { margin: 0; padding-left: 1.25rem; }
.pub-list li, .cert-list li { margin-bottom: var(--space-md); }
.pub-list li:last-child, .cert-list li:last-child { margin-bottom: 0; }
.pub-list strong a, .cert-list a {
  color: var(--color-text);
  text-decoration: none;
}
.pub-list strong a:hover, .cert-list a:hover {
  color: var(--color-accent);
  text-decoration: underline;
}
.pub-venue { display: block; font-weight: normal; font-size: 0.9rem; color: var(--color-text-muted); margin-top: var(--space-xs); }

.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--space-lg);
  margin-bottom: var(--space-xl);
}
.contact-item {
  display: flex;
  flex-direction: column;
  padding: var(--space-md);
  background: var(--color-surface);
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  text-decoration: none;
  color: inherit;
  transition: border-color var(--transition), box-shadow var(--transition);
}
a.contact-item:hover {
  border-color: var(--color-accent);
  box-shadow: var(--shadow);
}
.contact-label {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  margin-bottom: var(--space-xs);
}
.contact-value { font-weight: 500; }

.contact-cta {
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
  margin-bottom: var(--space-xl);
}
.contact-cta .btn { margin-right: var(--space-sm); }
.contact-note { color: var(--color-text-muted); font-size: 0.95rem; margin: 0; }

.site-footer {
  padding: var(--space-xl) var(--space-lg);
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.9rem;
  border-top: 1px solid var(--color-border);
}

@media (max-width: 700px) {
  .nav-toggle { display: flex; }
  .nav-links {
    position: fixed;
    top: 0;
    right: 0;
    height: 100vh;
    width: 240px;
    background: var(--color-surface);
    flex-direction: column;
    padding: var(--space-2xl) var(--space-lg);
    gap: var(--space-md);
    box-shadow: -4px 0 20px rgba(0,0,0,0.1);
    transform: translateX(100%);
    transition: transform 0.25s ease;
  }
  .nav-links.is-open { transform: translateX(0); }
  .hero-cta { flex-direction: column; }
  .timeline { padding-left: var(--space-lg); }
  .timeline-marker { left: calc(-1 * var(--space-lg) + 2px); }
}

@media print {
  :root { --color-bg: #fff; --color-surface: #fff; --color-border: #ccc; }
  .site-header { position: static; background: #fff; }
  .nav-toggle { display: none !important; }
  .nav-links { display: flex !important; transform: none !important; position: static !important; height: auto !important; width: auto !important; box-shadow: none !important; }
  .hero { min-height: auto; padding: var(--space-xl) 0; page-break-after: avoid; }
  .section { padding: var(--space-lg) 0; page-break-inside: avoid; }
  .btn { border: 1px solid #333; }
  .card, .project-card { box-shadow: none; border: 1px solid #ddd; }
  .contact-item { break-inside: avoid; }
  a[href]::after { content: none; }
  body { font-size: 11pt; }
}