/* === Design Tokens === */
:root {
  --bg-primary: #0A0A0A;
  --bg-secondary: #111111;
  --bg-tertiary: #1A1A1A;
  --text-primary: #E8E8E8;
  --text-secondary: #888888;
  --accent: #E8E8E8;
  --accent-dim: #E8E8E833;
  --border: #222222;
  --unit: 8px;
  --max-width: 720px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-primary);
  background: var(--bg-primary);
  overflow-x: hidden;
}

a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 200ms ease;
}

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

.hidden { display: none !important; }

/* === Canvas === */
#particle-canvas {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
  will-change: transform;
}

/* === Layout === */
main {
  position: relative;
  z-index: 1;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 calc(var(--unit) * 3);
}

/* === Sections — staggered fade-in === */
.hero, .about, .apps, .experiments, .research, .footer {
  opacity: 0;
  transform: translateY(50px);
  animation: fadeUp 0.8s ease forwards;
}

.hero        { animation-delay: 0ms; }
.about       { animation-delay: 100ms; }
.apps        { animation-delay: 200ms; }
.experiments { animation-delay: 300ms; }
.research    { animation-delay: 400ms; }
.footer      { animation-delay: 500ms; }

@keyframes fadeUp {
  to { opacity: 1; transform: translateY(0); }
}

/* === Hero === */
.hero {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding: calc(var(--unit) * 16) calc(var(--unit) * 3) calc(var(--unit) * 4);
}

.hero-content { text-align: center; }

.hero-name {
  font-family: 'Syne', sans-serif;
  font-weight: 700;
  font-size: clamp(48px, 8vw, 64px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin-bottom: calc(var(--unit) * 2);
}

.hero-tagline {
  font-size: 15px;
  color: var(--text-secondary);
  letter-spacing: 0.05em;
  margin-bottom: calc(var(--unit) * 4);
}

/* === Social Links === */
.social-links {
  display: flex;
  gap: calc(var(--unit) * 3);
  justify-content: center;
}

.social-links a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  color: var(--text-secondary);
  transition: color 200ms ease, background 200ms ease, transform 200ms ease;
}

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

/* === About === */
.about { padding: calc(var(--unit) * 4) 0 calc(var(--unit) * 3); }

.about-text {
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-secondary);
  max-width: var(--max-width);
  margin: 0 auto;
}

/* === Section Label === */
.section-label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--text-secondary);
  margin-bottom: calc(var(--unit) * 2);
}

/* === Cards (shared) === */
.card-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: calc(var(--unit) * 3);
}

.card {
  display: flex;
  flex-direction: column;
  padding: calc(var(--unit) * 4);
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 8px;
  transition: transform 200ms ease, box-shadow 200ms ease, border-color 200ms ease;
  color: var(--text-primary);
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px var(--accent-dim);
  border-color: var(--accent-dim);
  color: var(--text-primary);
}

.card-header {
  display: flex;
  align-items: center;
  gap: calc(var(--unit) * 1.5);
  margin-bottom: calc(var(--unit) * 1);
}

.card-icon {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  object-fit: cover;
  filter: grayscale(1);
  transition: filter 300ms ease;
}

.card:hover .card-icon {
  filter: grayscale(0);
}

.card-title {
  font-family: 'Syne', sans-serif;
  font-weight: 600;
  font-size: 18px;
  flex: 1;
}

.card-arrow {
  font-size: 18px;
  color: var(--text-secondary);
  flex-shrink: 0;
  transition: color 200ms ease, transform 200ms ease;
}

.card:hover .card-arrow {
  color: var(--accent);
  transform: translateX(4px);
}

.card-desc {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* === Apps === */
.apps { padding: calc(var(--unit) * 4) 0; }

/* === Experiments === */
.experiments { padding: calc(var(--unit) * 4) 0; }

.experiments-desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: calc(var(--unit) * 3);
}

.chart-wrap {
  position: relative;
  width: 100%;
  height: 300px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}

#returns-chart {
  width: 100%;
  height: 100%;
  display: block;
}

.chart-tooltip {
  position: absolute;
  pointer-events: none;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 6px 10px;
  font-size: 12px;
  line-height: 1.5;
  color: var(--text-primary);
  white-space: nowrap;
  z-index: 10;
}

.chart-legend {
  display: flex;
  gap: calc(var(--unit) * 4);
  margin-top: calc(var(--unit) * 2);
  font-size: 13px;
  color: var(--text-secondary);
}

.legend-item {
  display: flex;
  align-items: center;
  gap: calc(var(--unit) * 1);
}

.legend-line {
  display: inline-block;
  width: 24px;
  height: 2px;
}

.legend-solid { background: var(--text-primary); }

.legend-dashed {
  background: repeating-linear-gradient(
    90deg,
    var(--text-secondary) 0 5px,
    transparent 5px 9px
  );
}

.chart-stat {
  font-size: 13px;
  color: var(--text-secondary);
  margin-top: calc(var(--unit) * 1);
}

/* === Research === */
.research { padding: calc(var(--unit) * 4) 0; }

.research-item + .research-item { margin-top: calc(var(--unit) * 4); }

.research-link {
  display: inline-flex;
  align-items: baseline;
  gap: calc(var(--unit) * 1.5);
  font-size: 15px;
  color: var(--text-primary);
  line-height: 1.6;
  text-decoration: none;
}

.research-link span:first-child {
  text-decoration: underline transparent;
  text-underline-offset: 4px;
  transition: text-decoration-color 200ms ease;
}

.research-link:hover span:first-child {
  text-decoration-color: var(--text-primary);
}

.research-link .card-arrow {
  margin-top: 0;
  flex-shrink: 0;
  transition: color 200ms ease, transform 200ms ease;
}

.research-link:hover .card-arrow {
  color: var(--text-primary);
  transform: translateX(4px);
}

.research-meta {
  font-size: 13px;
  color: var(--text-secondary);
  margin-top: calc(var(--unit) * 1);
}

/* === Footer === */
.footer {
  padding: calc(var(--unit) * 6) 0 calc(var(--unit) * 12);
  border-top: 1px solid var(--border);
  margin-top: calc(var(--unit) * 8);
}

.footer .container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: calc(var(--unit) * 2);
}

.footer-degrees {
  font-size: 13px;
  color: var(--text-primary);
  text-align: center;
}

.footer-roles {
  font-size: 13px;
  color: var(--text-secondary);
  text-align: center;
}

.footer .social-links { margin-top: calc(var(--unit) * 1); }

.footer-copy {
  font-size: 12px;
  color: var(--text-secondary);
  opacity: 0.5;
}

/* === Responsive === */
@media (max-width: 768px) {
  .card-grid { grid-template-columns: 1fr; }

  .card-icon { filter: grayscale(0); }

  .hero {
    padding-top: calc(var(--unit) * 8);
    padding-bottom: calc(var(--unit) * 2);
  }

  .chart-wrap { height: 240px; }
}

/* === Reduced Motion === */
@media (prefers-reduced-motion: reduce) {
  .hero, .about, .apps, .experiments, .research, .footer {
    opacity: 1;
    transform: none;
    animation: none;
  }

  #particle-canvas { display: none; }
}