/* === Reset & Variables === */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg: #0d1117;
  --bg-alt: #161b22;
  --surface: #1c2128;
  --border: #30363d;
  --text: #e6edf3;
  --text-muted: #8b949e;
  --primary: #58a6ff;
  --primary-dim: rgba(88, 166, 255, 0.1);
  --accent-green: #3fb950;
  --accent-yellow: #d29922;
  --accent-red: #f85149;
  --accent-purple: #bc8cff;
  --accent-gold: #f0c040;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --mono: 'JetBrains Mono', 'Fira Code', monospace;
  --max-w: 1100px;
  --transition: 0.3s ease;
}

html { scroll-behavior: smooth; scroll-padding-top: 80px; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: #79c0ff; }

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

/* === Language Toggle === */
.lang-toggle {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 1001;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-family: var(--font);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
}
.lang-toggle:hover {
  border-color: var(--primary);
  background: var(--primary-dim);
  transform: scale(1.1);
}

/* === Navbar === */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(13, 17, 23, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.5px;
}
.nav-logo:hover { color: var(--primary); }
.nav-links { display: flex; gap: 32px; }
.nav-links a {
  color: var(--text-muted);
  font-size: 14px;
  font-weight: 500;
  transition: color var(--transition);
}
.nav-links a:hover { color: var(--text); }

.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.nav-hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  transition: all var(--transition);
}

/* === Hero === */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 100px 0 60px;
}
.hero-container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}
.hero-greeting {
  color: var(--primary);
  font-size: 16px;
  font-weight: 500;
  margin-bottom: 8px;
}
.hero-name {
  font-size: 56px;
  font-weight: 700;
  letter-spacing: -2px;
  line-height: 1.1;
  margin-bottom: 12px;
  background: linear-gradient(135deg, var(--text) 0%, var(--primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-title {
  font-size: 18px;
  color: var(--text-muted);
  margin-bottom: 20px;
}
.hero-desc {
  color: var(--text-muted);
  font-size: 15px;
  line-height: 1.8;
  margin-bottom: 24px;
  max-width: 520px;
}
.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 32px;
}
.tag {
  padding: 4px 14px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 500;
  background: var(--primary-dim);
  color: var(--primary);
  border: 1px solid rgba(88, 166, 255, 0.2);
}
.hero-links { display: flex; gap: 12px; flex-wrap: wrap; }
.btn {
  padding: 10px 24px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  display: inline-block;
}
.btn-primary {
  background: var(--primary);
  color: var(--bg);
}
.btn-primary:hover { background: #79c0ff; color: var(--bg); transform: translateY(-2px); }
.btn-outline {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-outline:hover { border-color: var(--primary); color: var(--primary); transform: translateY(-2px); }

/* Hero Card (code block) */
.hero-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}
.card-header {
  padding: 12px 16px;
  display: flex;
  gap: 8px;
  background: var(--bg-alt);
  border-bottom: 1px solid var(--border);
}
.dot { width: 12px; height: 12px; border-radius: 50%; }
.dot.red { background: var(--accent-red); }
.dot.yellow { background: var(--accent-yellow); }
.dot.green { background: var(--accent-green); }
.card-code {
  padding: 20px 24px;
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1.8;
  overflow-x: auto;
}
.card-code .kw { color: var(--accent-purple); }
.card-code .cls { color: var(--accent-green); }
.card-code .attr { color: #79c0ff; }
.card-code .str { color: #a5d6ff; }
.card-code .num { color: var(--accent-yellow); }
.card-code .cmt { color: var(--text-muted); }

/* === Sections === */
.section { padding: 80px 0; }
.section-alt { background: var(--bg-alt); }
.section-title {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 48px;
  letter-spacing: -1px;
  position: relative;
  padding-bottom: 16px;
}
.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 48px;
  height: 3px;
  background: var(--primary);
  border-radius: 2px;
}

/* === Publications === */
.pub-list { display: flex; flex-direction: column; gap: 24px; }
.pub-item {
  display: flex;
  gap: 24px;
  padding: 24px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  transition: all var(--transition);
}
.pub-item:hover {
  border-color: var(--primary);
  transform: translateX(4px);
}
.pub-venue {
  min-width: 100px;
  padding: 8px 12px;
  border-radius: 8px;
  font-size: 12px;
  font-weight: 700;
  text-align: center;
  height: fit-content;
  letter-spacing: 0.5px;
}
.pub-venue.accepted { background: rgba(63, 185, 80, 0.15); color: var(--accent-green); border: 1px solid rgba(63, 185, 80, 0.3); }
.pub-venue.review { background: rgba(210, 153, 34, 0.15); color: var(--accent-yellow); border: 1px solid rgba(210, 153, 34, 0.3); }
.pub-title { font-size: 17px; font-weight: 600; margin-bottom: 6px; }
.pub-authors { font-size: 14px; color: var(--text-muted); margin-bottom: 8px; }
.pub-desc { font-size: 14px; color: var(--text-muted); line-height: 1.7; margin-bottom: 12px; }
.pub-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.badge {
  padding: 3px 10px;
  border-radius: 12px;
  font-size: 11px;
  font-weight: 500;
  background: rgba(139, 148, 158, 0.15);
  color: var(--text-muted);
}
.badge-green { background: rgba(63, 185, 80, 0.15); color: var(--accent-green); }
.badge-yellow { background: rgba(210, 153, 34, 0.15); color: var(--accent-yellow); }
.badge-blue { background: var(--primary-dim); color: var(--primary); }

/* === Projects === */
.project-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
.project-card {
  padding: 28px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  transition: all var(--transition);
  position: relative;
}
.project-card:hover {
  border-color: var(--primary);
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3);
}
.project-card.highlight { border-color: var(--accent-gold); }
.project-medal {
  position: absolute;
  top: 16px;
  right: 16px;
  padding: 4px 12px;
  background: linear-gradient(135deg, #f0c040, #e6a817);
  color: #1c1c1c;
  font-size: 11px;
  font-weight: 800;
  border-radius: 6px;
  letter-spacing: 1px;
}
.project-card h3 { font-size: 20px; margin-bottom: 4px; }
.project-subtitle { font-size: 13px; color: var(--primary); margin-bottom: 12px; }
.project-desc { font-size: 14px; color: var(--text-muted); line-height: 1.7; margin-bottom: 16px; }
.project-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.project-tags span {
  padding: 3px 10px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 500;
  background: var(--primary-dim);
  color: var(--primary);
}

/* === Awards === */
.awards-list { display: flex; flex-direction: column; gap: 20px; }
.award-item {
  display: flex;
  gap: 24px;
  padding: 20px 24px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  transition: all var(--transition);
  align-items: center;
}
.award-item:hover { border-color: var(--primary); transform: translateX(4px); }
.award-year {
  min-width: 60px;
  font-size: 14px;
  font-weight: 700;
  color: var(--primary);
  font-family: var(--mono);
}
.award-content h3 { font-size: 16px; margin-bottom: 2px; }
.award-content p { font-size: 13px; color: var(--text-muted); }

/* === Contact === */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.contact-card {
  display: flex;
  gap: 16px;
  align-items: center;
  padding: 24px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  transition: all var(--transition);
  color: var(--text);
}
.contact-card:hover {
  border-color: var(--primary);
  transform: translateY(-4px);
  color: var(--text);
}
.contact-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: var(--primary-dim);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: 700;
  flex-shrink: 0;
}
.contact-card h3 { font-size: 14px; font-weight: 600; }
.contact-card p { font-size: 13px; color: var(--text-muted); }

/* === Footer === */
.footer {
  padding: 32px 0;
  text-align: center;
  border-top: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 13px;
}

/* === Scroll to Top === */
.scroll-top {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  font-size: 18px;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition);
  z-index: 999;
}
.scroll-top.visible { opacity: 1; visibility: visible; }
.scroll-top:hover { border-color: var(--primary); background: var(--primary-dim); }

/* === Animations === */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}
.hero-text > * { animation: fadeInUp 0.6s ease forwards; opacity: 0; }
.hero-text > *:nth-child(1) { animation-delay: 0.1s; }
.hero-text > *:nth-child(2) { animation-delay: 0.2s; }
.hero-text > *:nth-child(3) { animation-delay: 0.3s; }
.hero-text > *:nth-child(4) { animation-delay: 0.4s; }
.hero-text > *:nth-child(5) { animation-delay: 0.5s; }
.hero-text > *:nth-child(6) { animation-delay: 0.6s; }
.hero-visual { animation: fadeInUp 0.8s ease 0.4s forwards; opacity: 0; }

/* === Responsive === */
@media (max-width: 768px) {
  .hero-container { grid-template-columns: 1fr; gap: 40px; }
  .hero-name { font-size: 40px; }
  .hero-visual { order: -1; }
  .project-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .pub-item { flex-direction: column; gap: 12px; }
  .pub-venue { min-width: auto; width: fit-content; }

  .nav-links { display: none; }
  .nav-links.active {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 16px 24px;
    gap: 16px;
  }
  .nav-hamburger { display: flex; }

  .lang-toggle { top: 12px; right: 68px; width: 36px; height: 36px; font-size: 11px; }
}

@media (max-width: 480px) {
  .hero-name { font-size: 32px; }
  .card-code { font-size: 12px; padding: 16px; }
  .section { padding: 60px 0; }
  .section-title { font-size: 26px; }
}