:root {
  --primary: #2c3e50;
  --secondary: #3498db;
  --accent: #e74c3c;
  --light: #ecf0f1;
  --dark: #2c3e50;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  line-height: 1.6;
  color: var(--dark);
}

/* Navigation */
nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 5%;
  background: white;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
  position: fixed;
  width: 100%;
  top: 0;
  z-index: 1000;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--primary);
}

nav ul {
  display: flex;
  gap: 2rem;
  list-style: none;
}

nav a {
  text-decoration: none;
  color: var(--dark);
  font-weight: 500;
  transition: color 0.3s;
}

nav a:hover {
  color: var(--secondary);
}

/* Hero Section */
.hero {
  height: 100vh;
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  padding: 0 5%;
  background: linear-gradient(135deg, #fff 0%, var(--light) 100%);
}

.hero-content {
  padding-right: 2rem;
}

.hero h1 {
  font-size: 4rem;
  line-height: 1.2;
  margin-bottom: 1rem;
  color: var(--primary);
}

.hero p {
  font-size: 1.25rem;
  margin-bottom: 2rem;
  color: var(--dark);
}

.cta {
  padding: 1rem 2rem;
  font-size: 1.1rem;
  background: var(--secondary);
  color: white;
  border: none;
  border-radius: 5px;
  cursor: pointer;
  transition: transform 0.3s;
}

.cta:hover {
  transform: translateY(-2px);
}

/* Knowledge Graph Animation */
.knowledge-graph {
  width: 100%;
  height: 100%;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 200 200'%3E%3Cg fill='none' stroke='%233498db' stroke-width='2'%3E%3Ccircle cx='100' cy='100' r='80'/%3E%3Ccircle cx='100' cy='100' r='60'/%3E%3Ccircle cx='100' cy='100' r='40'/%3E%3C/g%3E%3C/svg%3E");
  background-size: contain;
  background-repeat: no-repeat;
  animation: rotate 20s linear infinite;
}

@keyframes rotate {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

/* Content Sections */
section {
  padding: 5rem 5%;
}

h2 {
  font-size: 2.5rem;
  text-align: center;
  margin-bottom: 3rem;
  color: var(--primary);
}

/* Stats Cards */
.stat-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
  margin-top: 3rem;
}

.stat-card {
  background: white;
  padding: 2rem;
  border-radius: 10px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  text-align: center;
}

.stat-card h3 {
  font-size: 2.5rem;
  color: var(--secondary);
  margin-bottom: 0.5rem;
}

/* Feature Grid */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
}

.feature-card {
  background: white;
  padding: 2rem;
  border-radius: 10px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  text-align: center;
}

.feature-card .icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

/* Benefits Section */
.benefits-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
}

.benefit {
  padding: 2rem;
  background: white;
  border-radius: 10px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

/* Pricing Section */
.pricing {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-top: 3rem;
}

.price-card {
  background: white;
  padding: 2rem;
  border-radius: 10px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  text-align: center;
}

.price-card.featured {
  transform: scale(1.05);
  border: 2px solid var(--secondary);
}

.price {
  font-size: 2.5rem;
  color: var(--secondary);
  margin: 1rem 0;
}

.signup-btn {
  width: 100%;
  padding: 1rem;
  background: var(--secondary);
  color: white;
  border: none;
  border-radius: 5px;
  cursor: pointer;
  transition: transform 0.3s;
}

.signup-btn:hover {
  transform: translateY(-2px);
}

/* Footer */
footer {
  background: var(--primary);
  color: white;
  padding: 4rem 5% 2rem;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-section h4 {
  margin-bottom: 1rem;
}

.footer-section ul {
  list-style: none;
}

.footer-section a {
  color: var(--light);
  text-decoration: none;
  transition: color 0.3s;
}

.footer-section a:hover {
  color: var(--secondary);
}

.social-links {
  display: flex;
  gap: 1rem;
  font-size: 1.5rem;
}

.copyright {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid rgba(255,255,255,0.1);
}

/* Responsive Design */
@media (max-width: 768px) {
  nav ul {
    display: none;
  }
  
  .hero {
    grid-template-columns: 1fr;
    text-align: center;
    height: auto;
    padding-top: 6rem;
  }
  
  .hero-content {
    padding-right: 0;
  }
  
  .hero h1 {
    font-size: 3rem;
  }
  
  .price-card.featured {
    transform: none;
  }
}