/* Rephrase メインサイト CSS */
:root {
  --primary-color: #2196F3;
  --secondary-color: #FF9800;
  --accent-color: #4CAF50;
  --text-color: #333;
  --light-gray: #f5f5f5;
  --border-color: #e0e0e0;
  --shadow: 0 2px 10px rgba(0,0,0,0.1);
  --gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

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

body {
  font-family: 'Arial', 'Helvetica', sans-serif;
  line-height: 1.6;
  color: var(--text-color);
  background-color: #fff;
}

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

/* Hero Section */
.hero-section {
  background: var(--gradient);
  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: rgba(0,0,0,0.1);
  z-index: 1;
}

.hero-section .container {
  position: relative;
  z-index: 2;
}

.hero-title {
  font-size: 3.5rem;
  margin-bottom: 20px;
  font-weight: 700;
  text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.hero-subtitle {
  font-size: 1.5rem;
  margin-bottom: 15px;
  font-weight: 300;
  opacity: 0.9;
}

.hero-description {
  font-size: 1.1rem;
  max-width: 600px;
  margin: 0 auto;
  opacity: 0.8;
}

/* Main Content */
.main-content {
  padding: 80px 0;
}

.navigation-section {
  text-align: center;
  margin-bottom: 80px;
}

.navigation-section h2 {
  font-size: 2.5rem;
  margin-bottom: 50px;
  color: var(--text-color);
}

.nav-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
  margin-top: 40px;
}

.nav-card {
  background: white;
  border-radius: 15px;
  padding: 40px 30px;
  box-shadow: var(--shadow);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  border: 2px solid var(--border-color);
}

.nav-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 5px 20px rgba(0,0,0,0.15);
}

.card-icon {
  font-size: 3rem;
  margin-bottom: 20px;
}

.nav-card h3 {
  font-size: 1.5rem;
  margin-bottom: 15px;
  color: var(--primary-color);
}

.nav-card p {
  color: #666;
  margin-bottom: 25px;
  line-height: 1.6;
}

.btn {
  display: inline-block;
  padding: 12px 30px;
  text-decoration: none;
  border-radius: 25px;
  font-weight: 600;
  transition: all 0.3s ease;
  font-size: 1rem;
}

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

.btn-primary:hover {
  background: #1976D2;
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(33, 150, 243, 0.4);
}

/* Features Section */
.features-section {
  background: var(--light-gray);
  padding: 80px 0;
  margin: 80px 0;
  border-radius: 20px;
}

.features-section h2 {
  text-align: center;
  font-size: 2.5rem;
  margin-bottom: 50px;
  color: var(--text-color);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 30px;
}

.feature-item {
  text-align: center;
  padding: 30px 20px;
  background: white;
  border-radius: 10px;
  box-shadow: var(--shadow);
}

.feature-icon {
  font-size: 2.5rem;
  margin-bottom: 20px;
}

.feature-item h3 {
  font-size: 1.3rem;
  margin-bottom: 15px;
  color: var(--primary-color);
}

.feature-item p {
  color: #666;
  line-height: 1.6;
}

/* About Section */
.about-section {
  text-align: center;
  padding: 60px 0;
}

.about-section h2 {
  font-size: 2.5rem;
  margin-bottom: 40px;
  color: var(--text-color);
}

.about-content {
  max-width: 800px;
  margin: 0 auto;
}

.about-content p {
  font-size: 1.1rem;
  line-height: 1.8;
  margin-bottom: 20px;
  color: #555;
}

/* Footer */
.footer {
  background: #333;
  color: white;
  padding: 40px 0;
  text-align: center;
}

.footer p {
  opacity: 0.8;
}

/* Responsive Design */
@media (max-width: 768px) {
  .hero-title {
    font-size: 2.5rem;
  }
  
  .hero-subtitle {
    font-size: 1.2rem;
  }
  
  .navigation-section h2,
  .features-section h2,
  .about-section h2 {
    font-size: 2rem;
  }
  
  .nav-cards {
    grid-template-columns: 1fr;
  }
  
  .features-grid {
    grid-template-columns: 1fr;
  }
  
  .container {
    padding: 0 15px;
  }
  
  .hero-section {
    padding: 60px 0;
  }
  
  .main-content {
    padding: 60px 0;
  }
  
  .features-section {
    padding: 60px 0;
    margin: 60px 0;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 2rem;
  }
  
  .nav-card {
    padding: 30px 20px;
  }
  
  .feature-item {
    padding: 20px 15px;
  }
}