:root {
  --primary-color: #2563eb;
  --primary-dark: #1d4ed8;
  --secondary-color: #64748b;
  --accent-color: #06b6d4;
  --background-color: #f8fafc;
  --surface-color: #ffffff;
  --text-color: #1e293b;
  --text-muted: #64748b;
  --border-color: #e2e8f0;
  --gradient-start: #2563eb;
  --gradient-end: #06b6d4;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background-color: var(--background-color);
  color: var(--text-color);
  line-height: 1.6;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-color);
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 32px;
}

.nav-links a {
  color: var(--text-color);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s;
}

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

.lang-selector {
  display: flex;
  gap: 8px;
}

.lang-btn {
  padding: 6px 12px;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 0.875rem;
  transition: all 0.2s;
}

.lang-btn:hover,
.lang-btn.active {
  background: var(--primary-color);
  color: white;
  border-color: var(--primary-color);
}

.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
  padding: 80px 24px;
  text-align: center;
}

.hero-content {
  max-width: 800px;
}

.hero-title {
  font-size: 4rem;
  font-weight: 800;
  color: white;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.hero-subtitle {
  font-size: 1.5rem;
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: 16px;
}

.hero-description {
  font-size: 1.125rem;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: 32px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 14px 28px;
  border-radius: 8px;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s;
  cursor: pointer;
  border: none;
  font-size: 1rem;
}

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

.btn-primary:hover {
  background: rgba(255, 255, 255, 0.9);
  transform: translateY(-2px);
}

.btn-secondary {
  background: transparent;
  color: white;
  border: 2px solid white;
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
}

.section {
  padding: 80px 0;
}

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

.section-title {
  font-size: 2.5rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 16px;
  color: var(--text-color);
}

.section-description {
  text-align: center;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto 48px;
}

.about-content {
  display: grid;
  gap: 48px;
}

.about-text {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}

.about-text p {
  margin-bottom: 16px;
  color: var(--text-muted);
  font-size: 1.125rem;
}

.about-highlights {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 24px;
  margin-top: 32px;
}

.highlight-card {
  background: var(--surface-color);
  padding: 32px;
  border-radius: 16px;
  text-align: center;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  transition: transform 0.2s;
}

.highlight-card:hover {
  transform: translateY(-4px);
}

.highlight-icon {
  font-size: 3rem;
  margin-bottom: 16px;
}

.highlight-card h3 {
  font-size: 1.25rem;
  margin-bottom: 8px;
  color: var(--text-color);
}

.highlight-card p {
  color: var(--text-muted);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--background-color);
  padding: 32px;
  border-radius: 16px;
  border: 1px solid var(--border-color);
  transition: all 0.2s;
}

.feature-card:hover {
  border-color: var(--primary-color);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.1);
}

.feature-card h3 {
  font-size: 1.25rem;
  margin-bottom: 12px;
  color: var(--text-color);
}

.feature-card p {
  color: var(--text-muted);
  line-height: 1.7;
}

.tools-section {
  background: var(--surface-color);
  padding: 40px;
  border-radius: 16px;
  margin-bottom: 32px;
  border: 1px solid var(--border-color);
}

.tools-subtitle {
  font-size: 1.5rem;
  margin-bottom: 12px;
  color: var(--text-color);
}

.tools-description {
  color: var(--text-muted);
  margin-bottom: 24px;
}

.tools-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

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

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

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

.tools-buttons .btn-secondary:hover {
  background: rgba(37, 99, 235, 0.1);
}

.version-selector {
  margin-top: 24px;
}

.version-tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.version-tab {
  padding: 12px 24px;
  border: 2px solid var(--border-color);
  border-radius: 8px;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  font-weight: 500;
  transition: all 0.2s;
}

.version-tab:hover {
  border-color: var(--primary-color);
  color: var(--primary-color);
}

.version-tab.active {
  background: var(--primary-color);
  border-color: var(--primary-color);
  color: white;
}

.version-panel {
  display: none;
  padding: 24px;
  background: var(--background-color);
  border-radius: 12px;
}

.version-panel.active {
  display: block;
}

.version-panel h4 {
  font-size: 1.25rem;
  margin-bottom: 8px;
  color: var(--text-color);
}

.version-panel p {
  color: var(--text-muted);
  margin-bottom: 16px;
}

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

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

.repo-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.repo-card {
  display: block;
  background: var(--background-color);
  padding: 24px;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  text-decoration: none;
  transition: all 0.2s;
}

.repo-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-4px);
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
}

.repo-card h3 {
  font-size: 1.125rem;
  color: var(--primary-color);
  margin-bottom: 8px;
}

.repo-card p {
  color: var(--text-muted);
  font-size: 0.9375rem;
  margin-bottom: 12px;
}

.repo-lang {
  display: inline-block;
  padding: 4px 12px;
  background: var(--surface-color);
  border-radius: 20px;
  font-size: 0.8125rem;
  color: var(--text-muted);
  border: 1px solid var(--border-color);
}

.timeline {
  max-width: 600px;
  margin: 48px auto 0;
  position: relative;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 80px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--border-color);
}

.timeline-item {
  display: flex;
  gap: 24px;
  margin-bottom: 32px;
  position: relative;
}

.timeline-date {
  width: 80px;
  flex-shrink: 0;
  font-weight: 600;
  color: var(--primary-color);
  text-align: right;
  padding-top: 4px;
}

.timeline-content {
  background: var(--surface-color);
  padding: 24px;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  flex: 1;
  position: relative;
}

.timeline-content::before {
  content: '';
  position: absolute;
  left: -30px;
  top: 12px;
  width: 12px;
  height: 12px;
  background: var(--primary-color);
  border-radius: 50%;
  border: 3px solid var(--background-color);
}

.timeline-content h3 {
  font-size: 1.125rem;
  margin-bottom: 8px;
  color: var(--text-color);
}

.timeline-content p {
  color: var(--text-muted);
}

.footer {
  background: var(--text-color);
  color: white;
  padding: 48px 0;
}

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

.footer-logo {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.footer-text {
  color: rgba(255, 255, 255, 0.7);
  margin-bottom: 16px;
}

.footer-links {
  display: flex;
  gap: 24px;
  justify-content: center;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  transition: color 0.2s;
}

.footer-links a:hover {
  color: white;
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .hero-title {
    font-size: 2.5rem;
  }

  .hero-subtitle {
    font-size: 1.25rem;
  }

  .section-title {
    font-size: 2rem;
  }

  .tools-section {
    padding: 24px;
  }

  .timeline::before {
    left: 0;
  }

  .timeline-item {
    flex-direction: column;
    gap: 12px;
  }

  .timeline-date {
    text-align: left;
    width: auto;
  }

  .timeline-content::before {
    left: -8px;
    top: -24px;
  }
}