:root {
  --color-primary: #1a5c2e;
  --color-primary-dark: #0f3d1d;
  --color-primary-light: #2d8a47;
  --color-accent: #e8a838;
  --color-accent-dark: #c4882a;
  --color-bg: #ffffff;
  --color-bg-alt: #f7faf8;
  --color-text: #1a1a1a;
  --color-text-light: #555555;
  --color-border: #e0e0e0;
  --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  --max-width: 1200px;
  --nav-height: 72px;
  --radius: 8px;
  --shadow: 0 2px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.12);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
}

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

img {
  max-width: 100%;
  height: auto;
  display: block;
}

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

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

/* Navigation */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  display: flex;
  align-items: center;
}

.nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

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

.nav-logo span {
  color: var(--color-accent);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-light);
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--color-primary);
}

.nav-links a.btn-primary {
  color: white;
}

.nav-links a.btn-primary:hover {
  color: white;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s, background 0.2s;
  border: none;
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow);
}

.btn-primary {
  background: var(--color-primary);
  color: white;
}

.btn-primary:hover {
  background: var(--color-primary-dark);
}

.btn-secondary {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn-secondary:hover {
  background: var(--color-bg-alt);
}

.btn-accent {
  background: var(--color-accent);
  color: white;
}

.btn-accent:hover {
  background: var(--color-accent-dark);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  margin: 6px 0;
  transition: transform 0.3s, opacity 0.3s;
}

/* Hero */
.hero {
  padding: 160px 0 100px;
  min-height: 90vh;
  display: flex;
  align-items: center;
}

.hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.hero-content h1 {
  font-size: 3.2rem;
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
}

.hero-content h1 .highlight {
  color: var(--color-primary);
}

.hero-content p {
  font-size: 1.2rem;
  color: var(--color-text-light);
  margin-bottom: 32px;
  max-width: 480px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

/* Carousel */
.hero-carousel {
  border-radius: 16px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  background: var(--color-bg-alt);
  position: relative;
}

.carousel-track {
  display: flex;
  transition: transform 0.4s ease;
}

.carousel-track img {
  min-width: 100%;
  width: 100%;
  aspect-ratio: 4/3;
  object-fit: cover;
  flex-shrink: 0;
}

.carousel-controls {
  position: absolute;
  bottom: 16px;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
}

.carousel-btn {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: none;
  background: transparent;
  color: rgba(255,255,255,0.8);
  font-size: 0.75rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color 0.2s;
}

.carousel-btn:hover {
  color: white;
}

.carousel-dots {
  display: flex;
  gap: 8px;
}

.carousel-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: rgba(255,255,255,0.5);
  border: none;
  cursor: pointer;
  padding: 0;
  transition: background 0.2s, transform 0.2s;
}

.carousel-dot.active {
  background: white;
  transform: scale(1.3);
}

/* Section shared styles */
section {
  padding: 100px 0;
}

.section-label {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.section-title {
  font-size: 2.4rem;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--color-text-light);
  max-width: 600px;
  margin-bottom: 48px;
}

/* Problem */
.problem {
  background: var(--color-bg-alt);
}

.problem-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  margin-top: 48px;
}

.stat-card {
  background: white;
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.stat-card .number {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1;
  margin-bottom: 8px;
}

.stat-card .label {
  font-size: 0.95rem;
  color: var(--color-text-light);
  line-height: 1.4;
}

/* Solution */
.solution-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.solution-card {
  padding: 32px;
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  transition: box-shadow 0.2s, transform 0.2s;
}

.solution-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.solution-card .icon {
  width: 48px;
  height: 48px;
  background: var(--color-bg-alt);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  font-size: 1.5rem;
}

.solution-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.solution-card p {
  font-size: 0.95rem;
  color: var(--color-text-light);
  line-height: 1.5;
}

/* Teleoperation Demo */
.teleop-demo {
  background: var(--color-bg-alt);
}

.teleop-content {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 48px;
  align-items: center;
}

.teleop-video {
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  background: #1a1a1a;
}

.placeholder-video {
  aspect-ratio: 16/9;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #888;
  font-size: 1rem;
  padding: 24px;
}

.teleop-features {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.teleop-feature strong {
  display: block;
  font-size: 1.05rem;
  margin-bottom: 4px;
}

.teleop-feature p {
  font-size: 0.95rem;
  color: var(--color-text-light);
  line-height: 1.5;
}

/* How it Works */
.how-it-works {
  background: var(--color-bg-alt);
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 48px;
  position: relative;
}

.steps::before {
  content: '';
  position: absolute;
  top: 32px;
  left: calc(16.67% + 32px);
  right: calc(16.67% + 32px);
  height: 2px;
  background: var(--color-border);
}

.step {
  text-align: center;
}

.step-number {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: var(--color-primary);
  color: white;
  font-size: 1.5rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  position: relative;
  z-index: 1;
}

.step h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.step p {
  font-size: 0.95rem;
  color: var(--color-text-light);
}

/* Technology / Vision */
.vision-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.vision-text p {
  color: var(--color-text-light);
  margin-bottom: 16px;
  font-size: 1.05rem;
}

.vision-text p strong {
  color: var(--color-text);
}

.vision-image {
  background: var(--color-bg-alt);
  border-radius: 16px;
  aspect-ratio: 4/3;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-border);
}

.vision-image .placeholder {
  color: var(--color-text-light);
  font-size: 0.9rem;
  text-align: center;
  padding: 24px;
}

/* Team */
.team {
  background: var(--color-bg-alt);
}

.team-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 32px;
}

.team-card {
  background: white;
  border-radius: var(--radius);
  padding: 32px;
  text-align: center;
  box-shadow: var(--shadow);
}

.team-card .avatar {
  width: 96px;
  height: 96px;
  border-radius: 50%;
  background: var(--color-border);
  margin: 0 auto 16px;
  object-fit: cover;
  object-position: center top;
}

.team-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.team-card .role {
  font-size: 0.85rem;
  color: var(--color-primary);
  font-weight: 600;
  margin-bottom: 12px;
}

.team-card p {
  font-size: 0.9rem;
  color: var(--color-text-light);
}

/* CTA / Contact */
.contact {
  background: var(--color-primary-dark);
  color: white;
  text-align: center;
}

.contact .section-label {
  color: var(--color-accent);
}

.contact .section-title {
  color: white;
}

.contact .section-subtitle {
  color: rgba(255,255,255,0.8);
  margin: 0 auto 40px;
}

.contact-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 32px;
}

.contact-email {
  font-size: 0.95rem;
  color: rgba(255,255,255,0.7);
}

.contact-email a {
  color: var(--color-accent);
  text-decoration: underline;
}

/* Footer */
.footer {
  padding: 32px 0;
  border-top: 1px solid var(--color-border);
}

.footer .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

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

.footer-links {
  display: flex;
  gap: 24px;
  list-style: none;
}

.footer-links a {
  font-size: 0.85rem;
  color: var(--color-text-light);
  transition: color 0.2s;
}

.footer-links a:hover {
  color: var(--color-primary);
}

/* Mobile */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: white;
    flex-direction: column;
    padding: 24px;
    gap: 16px;
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow);
  }

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

  .nav-toggle {
    display: block;
  }

  .hero {
    padding: 120px 0 60px;
    min-height: auto;
  }

  .hero .container {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .hero-content h1 {
    font-size: 2.2rem;
  }

  .hero-image {
    order: -1;
  }

  .problem-stats {
    grid-template-columns: 1fr;
  }

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

  .steps {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .steps::before {
    display: none;
  }

  .teleop-content {
    grid-template-columns: 1fr;
  }

  .vision-content {
    grid-template-columns: 1fr;
  }

  .section-title {
    font-size: 1.8rem;
  }

  .footer .container {
    flex-direction: column;
    gap: 16px;
    text-align: center;
  }
}