:root {
  --bg: #FFFFFF;
  --surface: #FAFAFA;
  --surface-hover: #F4F4F5;
  --border: #E4E4E7;
  --border-light: #F0F0F2;
  --text: #00040D;
  --text-muted: rgba(0, 4, 13, 0.65);
  --text-faint: rgba(0, 4, 13, 0.55);
  --brand-blue: #2C5DFE;
  --brand-blue-hover: #1E46CC;
  --brand-blue-bg: rgba(44, 93, 254, 0.08);
  
  --green: #1B5E20;
  --green-bg: #E8F5E9;
  --green-border: #C8E6C9;

  --amber: #B78103;
  --amber-bg: #FFF8E1;
  --amber-border: #FFE082;

  --purple: #4338CA;
  --purple-bg: #EEF2FF;
  --purple-border: #C7D2FE;

  --font-main: 'Instrument Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'IBM Plex Mono', 'Menlo', monospace;
  --container-max: 1140px;
}

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

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
}

body {
  font-family: var(--font-main);
  background: var(--bg);
  color: var(--text);
  font-size: 16px;
  line-height: 1.6;
  min-height: 100vh;
}

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

/* Site Header */
.site-header {
  height: 72px;
  border-bottom: 1px solid var(--border-light);
  display: flex;
  align-items: center;
  background: rgba(255, 255, 255, 0.95);
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(10px);
}

.header-inner {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
}

.logo-svg {
  height: 32px;
  width: auto;
  display: block;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-link {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-muted);
  transition: color 0.15s ease;
}

.nav-link:hover,
.nav-link.active {
  color: var(--brand-blue);
}

.nav-gh {
  font-size: 14px;
  font-weight: 600;
  padding: 6px 14px;
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--text);
  transition: all 0.15s ease;
}

.nav-gh:hover {
  border-color: var(--brand-blue);
  color: var(--brand-blue);
  background: var(--brand-blue-bg);
}

/* Main Container */
.page-container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 32px;
}

/* Hero Section */
.hero {
  padding: 72px 0 64px;
}

.hero-label {
  font-family: var(--font-main);
  font-weight: 700;
  font-size: 16px;
  line-height: 24px;
  color: var(--brand-blue);
  margin-bottom: 24px;
  letter-spacing: 0.02em;
}

.hero-title {
  font-size: clamp(32px, 4.5vw, 54px);
  font-weight: 600;
  letter-spacing: -0.025em;
  line-height: 1.15;
  color: var(--text);
  max-width: 860px;
  margin-bottom: 28px;
}

.highlight {
  color: var(--brand-blue);
}

.hero-mission {
  font-size: clamp(17px, 2vw, 21px);
  line-height: 1.6;
  color: var(--text-muted);
  max-width: 680px;
  margin-bottom: 36px;
}

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

.primary-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--brand-blue);
  color: #FFFFFF;
  font-weight: 600;
  font-size: 15px;
  padding: 12px 26px;
  border-radius: 999px;
  border: 1px solid var(--brand-blue);
  cursor: pointer;
  transition: all 0.2s ease;
}

.primary-button:hover {
  background: var(--brand-blue-hover);
  border-color: var(--brand-blue-hover);
  transform: translateY(-1px);
}

.secondary-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  color: var(--text);
  font-weight: 600;
  font-size: 15px;
  padding: 12px 24px;
  border-radius: 999px;
  border: 1px solid var(--border);
  cursor: pointer;
  transition: all 0.2s ease;
}

.secondary-button:hover {
  border-color: var(--text);
  background: var(--surface);
  transform: translateY(-1px);
}

/* Sections Common */
.section {
  padding: 64px 0;
  border-top: 1px solid var(--border-light);
}

.section-head {
  margin-bottom: 36px;
}

.section-title {
  font-size: clamp(22px, 3vw, 32px);
  font-weight: 600;
  letter-spacing: -0.015em;
  color: var(--text);
  margin-bottom: 12px;
}

.section-subtext {
  font-size: 16px;
  color: var(--text-muted);
  line-height: 1.6;
  max-width: 640px;
}

/* Research Areas Grid */
.areas-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.area-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  transition: all 0.2s ease;
}

.area-card:hover {
  border-color: rgba(44, 93, 254, 0.4);
  background: #FFFFFF;
  box-shadow: 0 8px 24px rgba(0, 4, 13, 0.05);
  transform: translateY(-2px);
}

.area-name {
  font-size: 17px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 8px;
  line-height: 1.3;
}

.area-desc {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.55;
  margin-bottom: 18px;
  flex: 1;
}

.area-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: auto;
}

.tag {
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 3px 8px;
  background: #FFFFFF;
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text-muted);
}

/* Projects Grid - Clean without infographics */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}

.project-card {
  background: #FFFFFF;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 26px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  transition: all 0.2s ease;
  position: relative;
}

.project-card:hover {
  border-color: rgba(44, 93, 254, 0.45);
  box-shadow: 0 8px 24px rgba(0, 4, 13, 0.06);
  transform: translateY(-2px);
}

.project-card.coming-soon {
  border-style: dashed;
  background: var(--surface);
}

.project-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.project-name {
  font-size: 18px;
  font-weight: 600;
  color: var(--text);
  line-height: 1.3;
}

.project-name a {
  color: inherit;
  text-decoration: none;
  transition: color 0.15s ease;
}

.project-name a:hover {
  color: var(--brand-blue);
}

.badge {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  padding: 3px 8px;
  border-radius: 4px;
  letter-spacing: 0.02em;
  text-transform: lowercase;
  white-space: nowrap;
}

.badge-active {
  background: var(--green-bg);
  color: var(--green);
  border: 1px solid var(--green-border);
}

.badge-poc {
  background: var(--amber-bg);
  color: var(--amber);
  border: 1px solid var(--amber-border);
}

.badge-research {
  background: var(--purple-bg);
  color: var(--purple);
  border: 1px solid var(--purple-border);
}

.badge-soon {
  background: #FFFFFF;
  color: var(--text-muted);
  border: 1px dashed var(--border);
}

.project-desc {
  font-size: 14.5px;
  color: var(--text-muted);
  line-height: 1.6;
  flex: 1;
}

.project-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 14px;
  border-top: 1px solid var(--border-light);
  margin-top: auto;
  gap: 12px;
  flex-wrap: wrap;
}

.project-tags {
  display: flex;
  gap: 6px;
}

.project-links {
  display: flex;
  align-items: center;
  gap: 16px;
}

.link-action {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--text-muted);
  transition: color 0.15s ease;
}

.link-action:hover {
  color: var(--text);
}

.link-action.primary {
  color: var(--brand-blue);
}

.link-action.primary:hover {
  color: var(--brand-blue-hover);
}

.link-action.disabled {
  color: #6B7280;
  cursor: default;
  pointer-events: none;
  opacity: 0.85;
}

/* Site Footer */
.site-footer {
  border-top: 1px solid var(--border-light);
  background: #FFFFFF;
  padding: 60px 0 40px;
  margin-top: 40px;
}

.footer-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 32px;
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 48px;
  align-items: start;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.footer-desc {
  font-size: 14.5px;
  color: var(--text-muted);
  line-height: 1.6;
  max-width: 440px;
}

.footer-meta {
  font-size: 13px;
  color: var(--text-faint);
  line-height: 1.8;
}

.footer-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}

.footer-col-title {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 14px;
}

.footer-link {
  display: block;
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 10px;
  transition: color 0.15s ease;
}

.footer-link:hover {
  color: var(--brand-blue);
}

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

@media (max-width: 768px) {
  .header-inner,
  .page-container,
  .footer-inner {
    padding-left: 20px;
    padding-right: 20px;
  }
  .nav-links {
    gap: 16px;
  }
  .hero {
    padding: 48px 0 44px;
  }
  .section {
    padding: 48px 0;
  }
  .areas-grid,
  .projects-grid,
  .footer-inner,
  .footer-nav {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

@media (max-width: 480px) {
  .site-header {
    height: 64px;
  }
  .header-inner {
    padding-left: 16px;
    padding-right: 16px;
  }
  .logo-svg {
    height: 26px;
  }
  .nav-links {
    gap: 12px;
  }
  .nav-link {
    font-size: 13.5px;
  }
  .nav-gh {
    font-size: 12.5px;
    padding: 4px 10px;
  }
  .hero-title {
    font-size: 28px;
  }
  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }
  .primary-button,
  .secondary-button {
    width: 100%;
  }
}