:root {
  --primary: #1E3A8A;
  --secondary: #3B82F6;
  --accent: #F3F4F6;
  --text: #333333;
  --light: #FFFFFF;
  --dark: #111827;
  --gray: #6B7280;
  --gradient: linear-gradient(135deg, #1E3A8A 0%, #3B82F6 100%);
}

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

body {
  font-family: 'Inter', 'PingFang SC', sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--light);
  overflow-x: hidden;
}

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

.header {
  background: var(--gradient);
  color: var(--light);
  padding: 2rem 0;
  text-align: center;
  position: relative;
  overflow: hidden;
  margin-bottom: 3rem;
}

.header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle at 20% 50%, rgba(255,255,255,0.1) 0%, transparent 50%);
}

.header h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  position: relative;
  z-index: 2;
  text-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.header p {
  font-size: 1.2rem;
  max-width: 800px;
  margin: 0 auto;
  position: relative;
  z-index: 2;
  opacity: 0.9;
}

.notice {
  background: var(--accent);
  color: var(--primary);
  padding: 1rem;
  text-align: center;
  font-weight: bold;
  margin-bottom: 2rem;
  border-radius: 8px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

.nav {
  display: flex;
  justify-content: center;
  margin-bottom: 3rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.nav-item {
  background: var(--light);
  padding: 1rem 2rem;
  border-radius: 8px;
  color: var(--primary);
  font-weight: 600;
  text-decoration: none;
  transition: all 0.3s ease;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  border: 2px solid transparent;
}

.nav-item:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 15px rgba(0,0,0,0.1);
  border-color: var(--secondary);
}

.content {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.section {
  background: var(--light);
  border-radius: 12px;
  padding: 2.5rem;
  box-shadow: 0 10px 15px rgba(0,0,0,0.05);
  transition: transform 0.3s ease;
  position: relative;
  overflow: hidden;
}

.section:hover {
  transform: translateY(-5px);
}

.section::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--gradient);
}

.section h2 {
  color: var(--primary);
  margin-bottom: 1.5rem;
  font-size: 1.8rem;
  position: relative;
  padding-bottom: 0.5rem;
}

.section h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 3px;
  background: var(--secondary);
}

.section h3 {
  color: var(--secondary);
  margin: 1.5rem 0 1rem;
  font-size: 1.4rem;
}

.section p {
  margin-bottom: 1.5rem;
  font-size: 1.1rem;
  line-height: 1.8;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.card {
  background: var(--light);
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  transition: all 0.3s ease;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 20px rgba(0,0,0,0.15);
}

.card-img {
  height: 200px;
  background-size: cover;
  background-position: center;
}

.card-body {
  padding: 1.5rem;
}

.card-title {
  color: var(--primary);
  margin-bottom: 0.5rem;
  font-size: 1.2rem;
}

.card-text {
  color: var(--gray);
  font-size: 0.95rem;
  margin-bottom: 1rem;
}

.card-link {
  display: inline-block;
  color: var(--secondary);
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s ease;
}

.card-link:hover {
  color: var(--primary);
  transform: translateX(3px);
}

pre {
  background: #f5f7fa;
  border-radius: 8px;
  padding: 1.5rem;
  overflow-x: auto;
  margin: 1.5rem 0;
  font-family: 'Courier New', monospace;
  font-size: 0.95rem;
  line-height: 1.5;
  border-left: 4px solid var(--secondary);
}

code {
  font-family: 'Courier New', monospace;
  background: rgba(59, 130, 246, 0.1);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  color: var(--secondary);
  font-size: 0.9rem;
}

.footer {
  background: var(--dark);
  color: var(--light);
  padding: 3rem 0;
  text-align: center;
  margin-top: 3rem;
}

.footer p {
  opacity: 0.8;
  font-size: 0.9rem;
}

@media (max-width: 768px) {
  .header h1 {
    font-size: 2rem;
  }
  
  .header p {
    font-size: 1rem;
  }
  
  .section {
    padding: 1.5rem;
  }
  
  .card-grid {
    grid-template-columns: 1fr;
  }
  
  .nav {
    flex-direction: column;
    align-items: center;
  }
  
  .nav-item {
    width: 100%;
    text-align: center;
  }
}

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

.floating {
  animation: float 3s ease-in-out infinite;
}