:root {
  --primary-blue: #1E90FF;
  --primary-green: #32CD32;
  --accent-orange: #FFA500;
  --neutral-gray: #f5f5f5;
  --neutral-white: #ffffff;
  --dark-blue: #0a2463;
  --light-blue: #d6f1ff;
  --gold: #ffd700;
}

body {
  font-family: 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
  margin: 0;
  padding: 0;
  background-color: var(--neutral-gray);
  color: #333;
  line-height: 1.6;
  font-size: 16px;
}

.header {
  background: linear-gradient(135deg, var(--primary-blue), var(--primary-green));
  color: var(--neutral-white);
  padding: 2rem 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.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: 0;
  position: relative;
  z-index: 1;
  text-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.notice {
  background-color: var(--gold);
  color: var(--dark-blue);
  padding: 1rem;
  text-align: center;
  font-weight: bold;
  margin-bottom: 2rem;
  border-radius: 0 0 8px 8px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

article {
  background-color: var(--neutral-white);
  border-radius: 8px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
  padding: 3rem;
  margin: 2rem 0;
}

article h2 {
  color: var(--dark-blue);
  font-size: 2rem;
  margin-top: 0;
  padding-bottom: 1rem;
  border-bottom: 2px solid var(--light-blue);
}

article h3 {
  color: var(--primary-blue);
  font-size: 1.5rem;
  margin: 2rem 0 1rem;
}

article p {
  margin-bottom: 1.5rem;
}

.card-container {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(500px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.card {
  background-color: var(--neutral-white);
  border-radius: 12px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
  transition: all 0.3s ease;
  padding: 1.5rem;
  border: 1px solid rgba(0,0,0,0.05);
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 25px rgba(0,0,0,0.15);
}

.card img {
  width: 100%;
  height: auto;
  border-radius: 8px;
  margin-bottom: 1rem;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  transition: transform 0.3s ease;
}

.card:hover img {
  transform: scale(1.02);
}

pre {
  background-color: #f8f8f8;
  border-radius: 8px;
  padding: 1.5rem;
  overflow-x: auto;
  margin: 1.5rem 0;
  border-left: 4px solid var(--primary-blue);
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  line-height: 1.5;
}

code {
  font-family: 'Courier New', monospace;
  background-color: rgba(30, 144, 255, 0.1);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  color: var(--primary-blue);
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  background-color: var(--neutral-white);
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-links {
  display: flex;
  gap: 2rem;
}

.nav-links a {
  color: var(--dark-blue);
  text-decoration: none;
  font-weight: 600;
  position: relative;
  padding: 0.5rem 0;
}

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

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

.footer {
  background-color: var(--dark-blue);
  color: var(--neutral-white);
  padding: 2rem 0;
  text-align: center;
  margin-top: 3rem;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-bottom: 1rem;
}

.footer-links a {
  color: var(--neutral-white);
  text-decoration: none;
  opacity: 0.8;
  transition: opacity 0.3s ease;
}

.footer-links a:hover {
  opacity: 1;
}

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

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

@media (max-width: 768px) {
  .card-container {
    grid-template-columns: 1fr;
  }
  
  .navbar {
    flex-direction: column;
    padding: 1rem;
  }
  
  .nav-links {
    margin-top: 1rem;
    gap: 1rem;
  }
  
  article {
    padding: 1.5rem;
  }
}

@media (max-width: 480px) {
  .header h1 {
    font-size: 2rem;
  }
  
  article h2 {
    font-size: 1.5rem;
  }
  
  article h3 {
    font-size: 1.25rem;
  }
}