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

:root {
  --color-bg: #0a0a0b;
  --color-bg-alt: #111113;
  --color-surface: #1a1a1f;
  --color-border: #2a2a30;
  --color-text: #e4e4e7;
  --color-text-muted: #8b8b95;
  --color-accent: #6366f1;
  --color-accent-hover: #818cf8;
  --color-accent-glow: rgba(99, 102, 241, 0.15);
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 0.2s ease;
  --max-width: 1100px;
}

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

body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition);
}

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

/* Header */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(10, 10, 11, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text) !important;
  letter-spacing: -0.02em;
}

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

.nav-links a {
  color: var(--color-text-muted);
  font-size: 0.875rem;
  font-weight: 500;
  padding: 6px 14px;
  border-radius: 6px;
  transition: all var(--transition);
}

.nav-links a:hover {
  color: var(--color-text);
  background: var(--color-surface);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all var(--transition);
}

/* Hero */
.hero {
  padding: 160px 0 100px;
  text-align: center;
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 16px;
}

.highlight {
  background: linear-gradient(135deg, var(--color-accent), #a78bfa);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.tagline {
  font-size: 1.25rem;
  color: var(--color-text-muted);
  max-width: 500px;
  margin: 0 auto;
}

/* Sections */
.section {
  padding: 80px 0;
}

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

.section h2 {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 40px;
  position: relative;
  display: inline-block;
}

.section h2::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 0;
  width: 40px;
  height: 3px;
  background: var(--color-accent);
  border-radius: 2px;
}

/* Card Grid */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
}

.card-grid--shorts {
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
}

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: all var(--transition);
}

.card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 1px var(--color-accent), 0 8px 32px rgba(0, 0, 0, 0.3);
  transform: translateY(-2px);
}

.card--link {
  display: block;
  color: inherit;
}

.card--link:hover {
  color: inherit;
}

.card--compact .card__body {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
}

.card--compact .card__body h3 {
  margin-bottom: 0;
  font-size: 0.95rem;
}

.card__inline-play {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  color: var(--color-text-muted);
  transition: all var(--transition);
}

.card--compact:hover .card__inline-play {
  color: var(--color-accent);
}

.card__thumb {
  aspect-ratio: 3 / 2;
  background: linear-gradient(135deg, var(--color-bg) 0%, #1a1a2e 100%);
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.card__play-icon--small {
  width: 32px;
  height: 32px;
}

.card__thumb--vertical {
  aspect-ratio: 9 / 16;
}

.card__play-icon {
  width: 48px;
  height: 48px;
  color: var(--color-text-muted);
  opacity: 0.5;
  transition: all var(--transition);
}

.card--link:hover .card__play-icon {
  color: var(--color-accent);
  opacity: 1;
  transform: scale(1.15);
}

.card__body {
  padding: 20px;
}

.card__body h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.card__body p {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  line-height: 1.5;
}

.card__date {
  display: inline-block;
  font-size: 0.8rem;
  color: var(--color-accent);
  font-weight: 600;
  font-family: var(--font-mono);
  margin-bottom: 8px;
}

.card__venue {
  color: var(--color-text-muted) !important;
  font-size: 0.85rem !important;
  margin-bottom: 8px !important;
}

/* List Items (Blog Posts, Papers) */
.list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.list-item {
  display: flex;
  gap: 24px;
  padding: 24px;
  border-radius: var(--radius);
  transition: background var(--transition);
}

.list-item:hover {
  background: var(--color-surface);
}

.list-item time,
.paper-venue {
  flex-shrink: 0;
  width: 120px;
  font-size: 0.85rem;
  font-family: var(--font-mono);
  color: var(--color-text-muted);
  padding-top: 2px;
}

.paper-venue {
  color: var(--color-accent);
  font-weight: 600;
}

.list-item h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 6px;
  letter-spacing: -0.01em;
}

.list-item h3 a {
  color: var(--color-text);
}

.list-item h3 a:hover {
  color: var(--color-accent);
}

.list-item p {
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

.authors {
  font-size: 0.85rem !important;
  margin-bottom: 6px;
}

.tag {
  display: inline-block;
  margin-top: 8px;
  padding: 3px 10px;
  background: var(--color-accent-glow);
  color: var(--color-accent);
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: 20px;
}

.tag--alt {
  background: rgba(251, 146, 60, 0.15);
  color: #fb923c;
}

.card__actions {
  display: flex;
  gap: 8px;
  margin-top: 14px;
}

.paper-links {
  display: flex;
  gap: 8px;
  margin-top: 12px;
}

/* Repo Cards */
.repo-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 10px;
}

.repo-icon {
  width: 18px;
  height: 18px;
  color: var(--color-text-muted);
  flex-shrink: 0;
}

.repo-header h3 {
  font-family: var(--font-mono);
  font-size: 1rem;
}

.repo-meta {
  display: flex;
  gap: 16px;
  margin-top: 12px;
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.repo-lang {
  display: flex;
  align-items: center;
  gap: 6px;
}

.repo-lang-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-accent);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  padding: 8px 18px;
  font-size: 0.85rem;
  font-weight: 600;
  border-radius: 6px;
  border: none;
  cursor: pointer;
  transition: all var(--transition);
}

.btn--small {
  padding: 5px 14px;
  font-size: 0.8rem;
  background: var(--color-accent);
  color: #fff;
}

.btn--small:hover {
  background: var(--color-accent-hover);
  color: #fff;
}

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

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

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

.timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--color-border);
}

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

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

.timeline-marker {
  position: absolute;
  left: -32px;
  top: 8px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--color-bg-alt);
  border: 3px solid var(--color-accent);
  z-index: 1;
}

.timeline-content {
  padding: 20px 24px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  transition: all var(--transition);
}

.timeline-content:hover {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 1px var(--color-accent), 0 4px 16px rgba(0, 0, 0, 0.2);
}

.timeline-date {
  font-size: 0.8rem;
  font-family: var(--font-mono);
  color: var(--color-accent);
  font-weight: 600;
}

.timeline-content h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin: 6px 0 4px;
}

.timeline-org {
  color: var(--color-text-muted);
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.timeline-content--link {
  display: block;
  color: inherit;
  text-decoration: none;
  cursor: pointer;
}

.timeline-degree {
  color: var(--color-text-muted);
  font-size: 0.8rem;
  margin-bottom: 4px;
}

.timeline-content p:last-child {
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

/* Contact */
.contact-links {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 20px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  color: var(--color-text);
  font-size: 0.95rem;
  transition: all var(--transition);
}

.contact-item:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  box-shadow: 0 0 0 1px var(--color-accent), 0 4px 16px rgba(0, 0, 0, 0.2);
}

.contact-icon {
  width: 22px;
  height: 22px;
  flex-shrink: 0;
  color: var(--color-accent);
}

/* Footer */
.site-footer {
  padding: 40px 0;
  text-align: center;
  border-top: 1px solid var(--color-border);
}

.site-footer p {
  color: var(--color-text-muted);
  font-size: 0.85rem;
}

/* Responsive */
@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: rgba(10, 10, 11, 0.95);
    backdrop-filter: blur(20px);
    padding: 16px 24px;
    border-bottom: 1px solid var(--color-border);
    gap: 4px;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links a {
    display: block;
    padding: 10px 14px;
  }

  .hero {
    padding: 120px 0 60px;
  }

  .section {
    padding: 60px 0;
  }

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

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

  .list-item {
    flex-direction: column;
    gap: 8px;
    padding: 20px 16px;
  }

  .list-item time,
  .paper-venue {
    width: auto;
  }
}

@media (max-width: 480px) {
  .card-grid--shorts {
    grid-template-columns: 1fr;
    max-width: 280px;
    margin: 0 auto;
  }
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.section {
  animation: fadeInUp 0.6s ease both;
}

.section:nth-child(2) { animation-delay: 0.05s; }
.section:nth-child(3) { animation-delay: 0.1s; }
.section:nth-child(4) { animation-delay: 0.15s; }
.section:nth-child(5) { animation-delay: 0.2s; }
.section:nth-child(6) { animation-delay: 0.25s; }

.hero {
  animation: fadeInUp 0.8s ease both;
}

.site-header {
  animation: fadeInUp 0.4s ease both;
}