/* Reset and base styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #ffffff;
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header and Navigation */
.site-header {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  border-bottom: 1px solid #e5e7eb;
}

.navbar {
  padding: 1rem 0;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-brand {
  font-size: 1.5rem;
  font-weight: 700;
  color: #1f2937;
  text-decoration: none;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-menu {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.nav-link {
  color: #4b5563;
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease;
  position: relative;
}

.nav-link:hover {
  color: #667eea;
}

.nav-link::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: -5px;
  left: 0;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  transition: width 0.3s ease;
}

.nav-link:hover::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  background: none;
  border: none;
  cursor: pointer;
  padding: 5px;
}

.nav-toggle span {
  width: 25px;
  height: 3px;
  background: #4b5563;
  margin: 3px 0;
  transition: 0.3s;
}

/* Main content */
.page-content {
  margin-top: 80px;
  min-height: calc(100vh - 80px);
}

/* Hero Section */
.hero-section {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 100px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('data:image/svg+xml,<svg width="60" height="60" viewBox="0 0 60 60" xmlns="http://www.w3.org/2000/svg"><g fill="none" fill-rule="evenodd"><g fill="%23ffffff" fill-opacity="0.05"><circle cx="30" cy="30" r="4"/></g></svg>') repeat;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  margin: 0 auto;
  padding: 0 20px;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  line-height: 1.1;
}

.hero-subtitle {
  font-size: 1.25rem;
  margin-bottom: 2rem;
  opacity: 0.9;
  font-weight: 300;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 12px 30px;
  border-radius: 50px;
  text-decoration: none;
  font-weight: 600;
  font-size: 1rem;
  transition: all 0.3s ease;
  border: 2px solid transparent;
}

.btn-primary {
  background: white;
  color: #667eea;
}

.btn-primary:hover {
  background: transparent;
  color: white;
  border-color: white;
}

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

.btn-secondary:hover {
  background: white;
  color: #667eea;
}

/* Sections */
.section {
  padding: 80px 0;
}

.bg-light {
  background-color: #f9fafb;
}

.section h2 {
  font-size: 2.5rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 1rem;
  color: #1f2937;
}

.lead {
  font-size: 1.25rem;
  text-align: center;
  color: #6b7280;
  margin-bottom: 3rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.section-intro {
  font-size: 1.125rem;
  text-align: center;
  color: #6b7280;
  margin-bottom: 3rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

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

.feature-card {
  background: white;
  padding: 2rem;
  border-radius: 12px;
  text-align: center;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px -3px rgba(0, 0, 0, 0.1);
}

.feature-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
}

.feature-card h3 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: #1f2937;
}

.feature-card p {
  color: #6b7280;
  line-height: 1.6;
}

/* Research Grid */
.research-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 2rem;
  margin-top: 3rem;
}

.research-card {
  background: white;
  padding: 2rem;
  border-radius: 12px;
  border: 1px solid #e5e7eb;
  transition: all 0.3s ease;
}

.research-card:hover {
  border-color: #667eea;
  transform: translateY(-2px);
  box-shadow: 0 10px 25px -3px rgba(102, 126, 234, 0.1);
}

.research-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: #1f2937;
}

.research-meta {
  font-size: 0.875rem;
  color: #667eea;
  margin-bottom: 1rem;
  font-weight: 500;
}

.research-card p {
  color: #6b7280;
  line-height: 1.6;
  margin-bottom: 1rem;
}

.read-more {
  color: #667eea;
  text-decoration: none;
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: color 0.3s ease;
}

.read-more:hover {
  color: #4f46e5;
}

/* Contact Section */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin: 3rem 0;
}

.contact-info {
  text-align: center;
  padding: 2rem;
}

.contact-info h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: #1f2937;
}

.contact-info p {
  color: #6b7280;
  margin-bottom: 1rem;
}

.contact-link {
  color: #667eea;
  text-decoration: none;
  font-weight: 500;
  font-size: 1.125rem;
}

.contact-link:hover {
  text-decoration: underline;
}

.social-links {
  text-align: center;
  margin-top: 3rem;
}

.social-link {
  display: inline-block;
  margin: 0 1rem;
  padding: 10px 20px;
  color: #667eea;
  text-decoration: none;
  border: 2px solid #667eea;
  border-radius: 25px;
  font-weight: 500;
  transition: all 0.3s ease;
}

.social-link:hover {
  background: #667eea;
  color: white;
}

/* Footer */
.site-footer {
  background: #1f2937;
  color: white;
  padding: 50px 0 20px;
}

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

.footer-section h4 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: white;
}

.footer-section p {
  color: #d1d5db;
  line-height: 1.6;
}

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

.footer-section ul li {
  margin-bottom: 0.5rem;
}

.footer-section ul li {
  color: #d1d5db;
}

.footer-social {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.footer-social a {
  color: #d1d5db;
  text-decoration: none;
  padding: 5px 10px;
  border-radius: 5px;
  transition: color 0.3s ease;
}

.footer-social a:hover {
  color: #667eea;
}

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid #374151;
}

.footer-bottom p {
  color: #9ca3af;
}

/* Responsive Design */
@media (max-width: 768px) {
  .nav-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    flex-direction: column;
    padding: 1rem;
    border-top: 1px solid #e5e7eb;
  }

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

  .nav-toggle {
    display: flex;
  }

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

  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }

  .section {
    padding: 60px 0;
  }

  .section h2 {
    font-size: 2rem;
  }

  .features-grid,
  .research-grid {
    grid-template-columns: 1fr;
  }

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

  .footer-social {
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 15px;
  }

  .hero-section {
    padding: 80px 0;
  }

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

  .hero-subtitle {
    font-size: 1.125rem;
  }

  .section {
    padding: 50px 0;
  }

  .feature-card,
  .research-card {
    padding: 1.5rem;
  }
}