/* Modern Social Science AI Lab Styles */

/* Global Variables */
:root {
  --primary-color: #2563eb;
  --secondary-color: #1e40af;
  --accent-color: #0ea5e9;
  --dark-bg: #1e293b;
  --light-bg: #f8fafc;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --border-color: #e2e8f0;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1);
  --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

/* Reset and Base Styles */
* {
  box-sizing: border-box;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--light-bg);
  margin: 0;
  padding: 0;
}

/* Modern Container */
.modern-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1rem;
}

/* Navigation Styles */
.modern-nav {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: var(--shadow-sm);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 1rem;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 700;
  font-size: 1.25rem;
}

.nav-logo {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  object-fit: cover;
  box-shadow: var(--shadow-md);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-link {
  text-decoration: none;
  color: var(--text-secondary);
  font-weight: 500;
  transition: color 0.3s ease;
  position: relative;
}

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

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary-color);
  transition: width 0.3s ease;
}

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

/* Hero Section Styles */
.hero-section {
  background: var(--gradient-primary);
  color: white;
  padding: 6rem 0;
  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 xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="50" cy="50" r="0.5" fill="white" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
  opacity: 0.3;
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 800;
  margin-bottom: 1.5rem;
  line-height: 1.1;
  background: linear-gradient(to right, #ffffff, #f0f9ff);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.5rem;
  font-weight: 300;
  margin-bottom: 2rem;
  opacity: 0.9;
  line-height: 1.4;
}

.hero-description {
  font-size: 1.125rem;
  max-width: 600px;
  margin: 0 auto 2rem;
  opacity: 0.8;
  line-height: 1.7;
}

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

.btn {
  padding: 0.875rem 2rem;
  border-radius: 0.75rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.3s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  border: none;
  font-size: 1rem;
}

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

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-xl);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.1);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.3);
  backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

/* Card Styles */
.modern-card {
  background: white;
  border-radius: 1rem;
  padding: 2rem;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
  height: 100%;
  display: flex;
  flex-direction: column;
}

.modern-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
  border-color: var(--primary-color);
}

.card-icon {
  width: 4rem;
  height: 4rem;
  background: var(--gradient-primary);
  border-radius: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  margin-bottom: 1.5rem;
  color: white;
}

.card-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.card-description {
  color: var(--text-secondary);
  line-height: 1.6;
  flex-grow: 1;
}

.card-link {
  color: var(--primary-color);
  text-decoration: none;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 1rem;
  transition: color 0.3s ease;
}

.card-link:hover {
  color: var(--secondary-color);
}

/* Features Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-top: 4rem;
}

/* Dual Empowerment Section */
.dual-empowerment {
  background: var(--light-bg);
  padding: 6rem 0;
}

.empowerment-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
  gap: 3rem;
  margin-top: 3rem;
}

.empowerment-card {
  background: white;
  border-radius: 1.5rem;
  padding: 3rem;
  text-align: center;
  box-shadow: var(--shadow-lg);
  position: relative;
  overflow: hidden;
}

.empowerment-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--gradient-primary);
}

.empowerment-icon {
  font-size: 3rem;
  margin-bottom: 1.5rem;
  display: block;
}

.empowerment-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
}

.empowerment-list {
  list-style: none;
  padding: 0;
  margin: 0;
  text-align: left;
}

.empowerment-list li {
  display: flex;
  align-items: flex-start;
  margin-bottom: 1rem;
  color: var(--text-secondary);
}

.empowerment-list li::before {
  content: '▶';
  color: var(--primary-color);
  margin-right: 0.75rem;
  font-size: 0.875rem;
  margin-top: 0.25rem;
}

/* CTA Section */
.cta-section {
  background: var(--dark-bg);
  color: white;
  padding: 4rem 0;
  text-align: center;
}

.cta-title {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.cta-description {
  font-size: 1.125rem;
  opacity: 0.8;
  max-width: 600px;
  margin: 0 auto 2rem;
  line-height: 1.7;
}

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

/* Footer Styles */
.modern-footer {
  background: var(--dark-bg);
  color: white;
  padding: 3rem 0 2rem;
}

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

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.footer-logo {
  width: 2rem;
  height: 2rem;
  background: var(--gradient-primary);
  border-radius: 0.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 700;
  font-size: 0.875rem;
}

.footer-title {
  font-size: 1.125rem;
  font-weight: 700;
}

.footer-description {
  color: rgba(255, 255, 255, 0.7);
  line-height: 1.6;
  margin-bottom: 1rem;
}

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

.footer-links {
  list-style: none;
  padding: 0;
  margin: 0;
}

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

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  transition: color 0.3s ease;
}

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

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 2rem;
  text-align: center;
  color: rgba(255, 255, 255, 0.5);
  font-size: 0.875rem;
}

/* Responsive Design */
@media (max-width: 1024px) {
  .nav-menu {
    gap: 1.5rem;
  }

  .features-grid {
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
  }

  .empowerment-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .footer-content {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
  }
}

@media (max-width: 768px) {
  .hero-title {
    font-size: 2.5rem;
  }

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

  .nav-menu {
    display: none;
    position: absolute;
    top: 80px;
    left: 0;
    right: 0;
    background: white;
    flex-direction: column;
    padding: 1rem;
    box-shadow: var(--shadow-lg);
    border-bottom: 1px solid var(--border-color);
  }

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

  #mobile-menu-btn {
    display: block !important;
  }

  .empowerment-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .modern-container {
    padding: 0 1rem;
  }

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

  .btn {
    width: 100%;
    max-width: 300px;
    justify-content: center;
  }

  .features-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 2rem;
  }

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

  .hero-description {
    font-size: 1rem;
  }

  .modern-card {
    padding: 1.5rem;
  }

  .empowerment-card {
    padding: 2rem;
  }

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

  .nav-brand {
    flex-direction: column;
    text-align: center;
    gap: 0.5rem;
  }

  .nav-logo {
    width: 40px;
    height: 40px;
  }
}

/* Animation Effects */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.animate-fade-in {
  animation: fadeInUp 0.8s ease-out forwards;
}

/* Scrollbar Styles */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--light-bg);
}

::-webkit-scrollbar-thumb {
  background: var(--primary-color);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--secondary-color);
}