/* ===========================
   CSS Variables & Reset
   =========================== */
:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #0e0e16;
  --bg-card: #12121c;
  --bg-card-hover: #181826;
  --accent: #00c8ff;
  --accent-dim: rgba(0, 200, 255, 0.15);
  --accent-glow: rgba(0, 200, 255, 0.3);
  --text-primary: #e0e0e8;
  --text-secondary: #9090a0;
  --text-muted: #606070;
  --border: rgba(255, 255, 255, 0.06);
  --border-accent: rgba(0, 200, 255, 0.2);
  --nav-height: 64px;
  --container-max: 1200px;
  --radius: 12px;
  --radius-sm: 8px;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
}

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

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

body {
  font-family: var(--font-body);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* ===========================
   Canvas Background
   =========================== */
#circuit-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}

/* ===========================
   Layout
   =========================== */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  position: relative;
  z-index: 1;
  padding: 100px 0;
  scroll-margin-top: var(--nav-height);
}

.section-alt {
  background: var(--bg-secondary);
}

/* ===========================
   Typography
   =========================== */
.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}

.section-title .accent {
  color: var(--accent);
}

.section-subtitle {
  color: var(--accent);
  margin-bottom: 16px;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.section-description {
  color: var(--text-secondary);
  max-width: 720px;
  margin-bottom: 48px;
  font-size: 1.05rem;
  line-height: 1.7;
}

.label-mono {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.05em;
}

/* ===========================
   Navigation
   =========================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--nav-height);
  z-index: 100;
  transition: background 0.3s, box-shadow 0.3s;
}

.navbar.scrolled {
  background: rgba(10, 10, 15, 0.85);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: 0 1px 0 var(--border);
}

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

.nav-logo {
  text-decoration: none;
  color: var(--text-primary);
}

.logo-text {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--accent);
}

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

.nav-link {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  padding: 6px 14px;
  border-radius: 6px;
  transition: color 0.2s, background 0.2s;
}

.nav-link:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.05);
}

.nav-link.active {
  color: var(--accent);
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.hamburger-line {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: transform 0.3s, opacity 0.3s;
}

.hamburger.open .hamburger-line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.hamburger.open .hamburger-line:nth-child(2) {
  opacity: 0;
}

.hamburger.open .hamburger-line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ===========================
   Hero Section
   =========================== */
.hero {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 120px 24px 80px;
}

.hero-content {
  max-width: 640px;
}

.profile-photo-wrapper {
  width: 160px;
  height: 160px;
  margin: 0 auto 32px;
  border-radius: 50%;
  padding: 3px;
  background: linear-gradient(135deg, var(--accent), rgba(0, 200, 255, 0.2));
  box-shadow: 0 0 40px rgba(0, 200, 255, 0.15);
}

.profile-photo {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  object-fit: cover;
  display: block;
}

.hero-name {
  font-size: 3rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 8px;
}

.hero-title {
  font-size: 1.15rem;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 4px;
}

.hero-affiliation {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.hero-bio {
  color: var(--text-secondary);
  font-size: 1.05rem;
  line-height: 1.7;
  margin-bottom: 32px;
}

.hero-actions {
  margin-bottom: 24px;
}

/* ===========================
   Buttons
   =========================== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.25s;
  cursor: pointer;
  border: none;
}

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

.btn-primary:hover {
  box-shadow: 0 0 20px rgba(0, 200, 255, 0.35);
  transform: translateY(-1px);
}

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

.btn-outline:hover {
  background: var(--accent-dim);
  border-color: var(--accent);
}

.btn-icon {
  flex-shrink: 0;
}

/* ===========================
   Social Links
   =========================== */
.social-links {
  display: flex;
  justify-content: center;
  gap: 16px;
}

.social-links a {
  color: var(--text-muted);
  transition: color 0.2s, transform 0.2s;
}

.social-links a:hover {
  color: var(--accent);
  transform: translateY(-2px);
}

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

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

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: border-color 0.3s, transform 0.3s, box-shadow 0.3s;
}

.card:hover {
  border-color: var(--border-accent);
  transform: translateY(-4px);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.card-icon {
  color: var(--accent);
  margin-bottom: 16px;
}

.card-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 12px;
  line-height: 1.3;
}

.card-text {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
  margin-bottom: 16px;
}

.card-date {
  display: block;
  color: var(--accent);
  margin-bottom: 12px;
}

.card-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--accent);
  background: var(--accent-dim);
  padding: 4px 10px;
  border-radius: 4px;
  margin-right: 6px;
  margin-bottom: 6px;
  letter-spacing: 0.03em;
}

/* ===========================
   Stats Bar
   =========================== */
.stats-bar {
  display: flex;
  justify-content: center;
  gap: 64px;
  margin-bottom: 64px;
  padding: 40px 0;
}

.stat {
  text-align: center;
}

.stat-number {
  display: block;
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--accent);
  font-family: var(--font-mono);
}

.stat-suffix {
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent);
  font-family: var(--font-mono);
}

.stat-label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* ===========================
   Timeline
   =========================== */
.timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
  padding-left: 40px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 11px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--border);
}

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

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

.timeline-marker {
  position: absolute;
  left: -40px;
  top: 4px;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--bg-primary);
  border: 2px solid var(--accent);
  box-shadow: 0 0 12px rgba(0, 200, 255, 0.2);
}

.timeline-marker::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
}

.timeline-content {
  padding-bottom: 8px;
}

.timeline-date {
  color: var(--accent);
  display: block;
  margin-bottom: 4px;
}

.timeline-title {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.timeline-title .accent {
  color: var(--accent);
  font-style: italic;
  font-weight: 400;
}

.timeline-place {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 4px;
}

.timeline-desc {
  color: var(--text-muted);
  font-size: 0.85rem;
  line-height: 1.5;
}

/* ===========================
   Publications
   =========================== */
.publication-list {
  max-width: 800px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin-bottom: 40px;
}

.publication-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 32px;
  transition: border-color 0.3s;
  position: relative;
}

.publication-item:hover {
  border-color: var(--border-accent);
}

.publication-citation-badge {
  position: absolute;
  top: 20px;
  right: 24px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent);
  background: var(--accent-dim);
  padding: 4px 12px;
  border-radius: 4px;
}

.publication-title {
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: 8px;
  padding-right: 120px;
}

.publication-venue {
  color: var(--text-secondary);
  font-size: 0.8rem;
}

.section-cta {
  text-align: center;
  margin-top: 32px;
}

/* ===========================
   Contact
   =========================== */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.contact-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
}

.contact-card:hover {
  border-color: var(--border-accent);
}

.contact-label {
  color: var(--accent);
  margin-bottom: 12px;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.contact-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.5;
}

.contact-card a {
  color: var(--accent);
  text-decoration: none;
  transition: opacity 0.2s;
}

.contact-card a:hover {
  opacity: 0.8;
}

.contact-kvk {
  margin-top: 10px;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.contact-links {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.contact-links a {
  color: var(--accent);
  text-decoration: none;
  font-size: 0.9rem;
  transition: opacity 0.2s;
}

.contact-links a:hover {
  opacity: 0.8;
}

/* ===========================
   Footer
   =========================== */
.footer {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 48px 24px;
  border-top: 1px solid var(--border);
}

.footer-tagline {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.footer-copy {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ===========================
   Responsive
   =========================== */
@media (max-width: 1024px) {
  .card-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .stats-bar {
    gap: 40px;
  }
}

@media (max-width: 768px) {
  :root {
    --nav-height: 56px;
  }

  /* Mobile Nav */
  .hamburger {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    width: 100%;
    background: rgba(10, 10, 15, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    flex-direction: column;
    padding: 16px 24px;
    gap: 4px;
    border-bottom: 1px solid var(--border);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.3s, opacity 0.3s;
  }

  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav-link {
    display: block;
    padding: 10px 14px;
    font-size: 0.95rem;
  }

  /* Hero */
  .hero {
    padding: 100px 20px 60px;
  }

  .hero-name {
    font-size: 2.2rem;
  }

  .profile-photo-wrapper {
    width: 130px;
    height: 130px;
  }

  /* Sections */
  .section {
    padding: 64px 0;
  }

  .section-title {
    font-size: 1.6rem;
  }

  /* Cards */
  .card-grid,
  .card-grid-2 {
    grid-template-columns: 1fr;
  }

  .card {
    padding: 24px;
  }

  /* Stats */
  .stats-bar {
    flex-direction: column;
    gap: 24px;
    align-items: center;
  }

  .stat-number {
    font-size: 2rem;
  }

  /* Timeline */
  .timeline {
    padding-left: 32px;
  }

  .timeline-marker {
    left: -32px;
    width: 20px;
    height: 20px;
  }

  .timeline::before {
    left: 9px;
  }

  /* Publications */
  .publication-citation-badge {
    position: static;
    display: inline-block;
    margin-bottom: 8px;
  }

  .publication-title {
    padding-right: 0;
  }

  /* Contact */
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .hero-name {
    font-size: 1.8rem;
  }

  .hero-bio {
    font-size: 0.95rem;
  }

  .container {
    padding: 0 16px;
  }
}