:root {
  --bg: #0e1016;
  --bg-alt: #13161c;
  --border: #22262f;
  --text: #eef1f5;
  --muted: #aab2bf;
  --dim: #8b949e;
  --accent: #5ee6c4;
  --accent-soft: rgba(94, 230, 196, 0.12);
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --max-width: 880px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }

h1, h2, h3 { line-height: 1.2; margin: 0; }

ul { margin: 0; padding: 0; }
li { list-style: none; }

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(14, 16, 22, 0.85);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 15px;
  color: var(--text);
}

.main-nav {
  display: flex;
  gap: 22px;
  font-size: 13px;
  color: var(--muted);
}

.main-nav a:hover { color: var(--accent); }

.header-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

.lang-switch {
  background: none;
  border: 1px solid var(--border);
  border-radius: 20px;
  color: var(--dim);
  font-family: var(--font-mono);
  font-size: 12px;
  padding: 5px 12px;
  cursor: pointer;
}

.lang-opt { color: var(--dim); }
.lang-opt.active { color: var(--accent); font-weight: 700; }
.lang-sep { margin: 0 2px; color: var(--border); }

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  width: 28px;
  height: 22px;
  background: none;
  border: none;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  height: 2px;
  background: var(--text);
  border-radius: 1px;
}

/* Hero */
.hero {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 64px 20px 0;
}

.hero-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  flex-wrap: wrap;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent);
  margin: 0 0 10px;
}

.hero-text h1 {
  font-size: 42px;
  font-weight: 700;
  margin-bottom: 14px;
}

.hero-tagline {
  color: var(--muted);
  font-size: 17px;
  max-width: 480px;
  margin: 0 0 26px;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  padding: 10px 18px;
  border-radius: 6px;
  border: 1px solid transparent;
}

.btn-primary {
  background: var(--accent);
  color: #06281f;
}

.btn-primary:hover { opacity: 0.88; }

.btn-ghost {
  border-color: var(--border);
  color: var(--text);
}

.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }

.hero-visual {
  position: relative;
  flex-shrink: 0;
  width: 160px;
}

.hero-photo {
  width: 160px;
  height: 160px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--border);
  display: block;
}

.hero-spark {
  width: 160px;
  height: 36px;
  margin-top: 14px;
  opacity: 0.8;
}

.stats-band {
  margin-top: 56px;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
}

.stat {
  padding: 22px 16px;
  border-left: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.stat:first-child { border-left: none; }

.stat-num {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  color: var(--accent);
}

.stat-label {
  font-size: 12.5px;
  color: var(--dim);
  line-height: 1.4;
}

/* Sections */
.section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 72px 20px;
  border-bottom: 1px solid var(--border);
}

.section:last-of-type { border-bottom: none; }

.section h2 {
  font-size: 24px;
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 28px;
}

.section-label {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent);
}

.section-text {
  color: var(--muted);
  font-size: 15.5px;
  max-width: 640px;
}

/* Timeline */
.timeline {
  position: relative;
  padding-left: 24px;
  border-left: 1px solid var(--border);
}

.timeline-item {
  position: relative;
  padding-bottom: 44px;
}

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

.timeline-marker {
  position: absolute;
  left: -29px;
  top: 4px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 4px var(--bg);
}

.timeline-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px;
}

.timeline-content h3 {
  font-size: 17px;
}

.timeline-date {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--dim);
  white-space: nowrap;
}

.timeline-org {
  color: var(--accent);
  font-size: 13.5px;
  margin: 2px 0 12px;
}

.timeline-content ul {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.timeline-content li {
  color: var(--muted);
  font-size: 14.5px;
  padding-left: 16px;
  position: relative;
}

.timeline-content li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--dim);
}

.timeline-content p {
  color: var(--muted);
  font-size: 14.5px;
  margin: 0;
}

/* Skills */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px 40px;
}

.skill-group h3 {
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--dim);
  margin-bottom: 14px;
}

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

.chip {
  font-size: 13px;
  padding: 6px 12px;
  border-radius: 20px;
  border: 1px solid var(--border);
  color: var(--muted);
}

.chip-primary {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-soft);
  font-weight: 600;
}

/* Publications */
.pub-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

/* Contact */
.contact-list {
  display: flex;
  flex-direction: column;
  max-width: 420px;
  margin-top: 24px;
}

.contact-row {
  display: flex;
  justify-content: space-between;
  padding: 16px 0;
  border-bottom: 1px solid var(--border);
}

.contact-row:hover .contact-value { color: var(--accent); }

.contact-label {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--dim);
}

.contact-value {
  font-size: 14.5px;
}

/* Footer */
.site-footer {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 32px 20px 60px;
  color: var(--dim);
  font-size: 12.5px;
}

/* Responsive */
@media (max-width: 760px) {
  .main-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    gap: 0;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.2s ease;
  }

  .main-nav.open { max-height: 400px; }

  .main-nav a {
    padding: 14px 20px;
    border-top: 1px solid var(--border);
  }

  .nav-toggle { display: flex; }

  .hero { padding-top: 40px; }

  .hero-text h1 { font-size: 32px; }

  .hero-inner { flex-direction: column-reverse; align-items: flex-start; }

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

  .stat:nth-child(2) { border-left: none; }
  .stat:nth-child(3), .stat:nth-child(4) { border-top: 1px solid var(--border); }

  .section { padding: 48px 20px; }

  .skills-grid { grid-template-columns: 1fr; }
}