:root {
  --primary: #0d47a1;
  --secondary: #00bcd4;
  --accent: #ff4081;
  --dark: #121a2e;
  --light: #f8f9fa;
  --text: #333;
  --text-light: #f8f9fa;
}

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

body {
  font-family: 'Roboto', sans-serif;
  color: var(--text);
  background: linear-gradient(135deg, var(--dark), #1a2a4a);
  line-height: 1.6;
  overflow-x: hidden;
}

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

.header {
  text-align: center;
  padding: 80px 0 40px;
  position: relative;
  overflow: hidden;
}

.header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    radial-gradient(circle, rgba(255,255,255,0.05) 1px, transparent 1px),
    linear-gradient(45deg, rgba(255,255,255,0.08) 1px, transparent 1px);
  background-size: 50px 50px;
  z-index: -1;
}

.header h1 {
  font-size: 3rem;
  margin-bottom: 20px;
  color: var(--text-light);
  background: linear-gradient(90deg, var(--secondary), var(--primary));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  animation: gradientShift 8s ease infinite;
  background-size: 200% 200%;
}

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

.header p {
  color: var(--text-light);
  opacity: 0.9;
  max-width: 800px;
  margin: 0 auto 30px;
  font-size: 1.2rem;
}

.notice {
  background: rgba(255,255,255,0.1);
  border-left: 4px solid var(--accent);
  padding: 15px;
  margin: 30px 0;
  border-radius: 0 5px 5px 0;
  color: var(--text-light);
}

.notice strong {
  color: var(--accent);
  font-weight: 500;
}

.article-container {
  background: rgba(255,255,255,0.95);
  border-radius: 15px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.2);
  padding: 40px;
  margin: 40px 0;
  position: relative;
  overflow: hidden;
}

.article-container::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 5px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
}

article {
  max-width: 900px;
  margin: 0 auto;
}

article h2 {
  font-size: 2rem;
  margin: 40px 0 20px;
  color: var(--primary);
  position: relative;
  padding-bottom: 10px;
}

article h2::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
}

article p {
  margin-bottom: 20px;
  font-size: 1.1rem;
  line-height: 1.7;
}

pre {
  background: #2d3748;
  border-radius: 8px;
  padding: 20px;
  margin: 25px 0;
  overflow: auto;
  box-shadow: inset 0 0 10px rgba(0,0,0,0.3);
}

code {
  font-family: 'Fira Code', monospace;
  color: #f8f9fa;
  font-size: 0.9rem;
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
  margin: 30px 0;
}

.image-card {
  background: white;
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 5px 15px rgba(0,0,0,0.1);
  transition: transform 0.3s, box-shadow 0.3s;
}

.image-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(0,0,0,0.2);
}

.image-card img {
  width: 100%;
  height: 300px;
  object-fit: cover;
  display: block;
}

.nav-tabs {
  display: flex;
  justify-content: center;
  margin: 40px 0;
  flex-wrap: wrap;
  gap: 10px;
}

.tab-link {
  padding: 12px 25px;
  background: rgba(13, 71, 161, 0.1);
  color: var(--primary);
  border-radius: 30px;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s;
  border: 2px solid transparent;
}

.tab-link:hover {
  background: var(--primary);
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(13, 71, 161, 0.3);
}

.tab-link.active {
  background: var(--primary);
  color: white;
  border-color: var(--secondary);
}

.footer {
  text-align: center;
  padding: 30px 0;
  color: var(--text-light);
  opacity: 0.8;
  font-size: 0.9rem;
}

@media (max-width: 768px) {
  .header h1 {
    font-size: 2.2rem;
  }
  
  .article-container {
    padding: 30px 20px;
  }
  
  article h2 {
    font-size: 1.7rem;
  }
  
  .image-grid {
    grid-template-columns: 1fr;
  }
}

/* Animation classes */
.fade-in {
  opacity: 0;
  animation: fadeIn 1s forwards;
}

@keyframes fadeIn {
  to { opacity: 1; }
}

.slide-up {
  transform: translateY(30px);
  opacity: 0;
  animation: slideUp 0.8s forwards;
}

@keyframes slideUp {
  to {
    transform: translateY(0);
    opacity: 1;
  }
}