:root {
  --primary: #1e3c72;
  --secondary: #2a5298;
  --accent: #00c6ff;
  --light: #f5f5f5;
  --dark: #333333;
  --success: #4CAF50;
  --warning: #FFC107;
  --danger: #F44336;
  --radius: 12px;
  --shadow: 0 4px 20px rgba(0,0,0,0.1);
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', sans-serif;
}

body {
  background: linear-gradient(135deg, #f5f7fa 0%, #e4e8f0 100%);
  color: var(--dark);
  line-height: 1.6;
  min-height: 100%;
  overflow-x: hidden;
}

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

.header {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: white;
  padding: 40px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
  margin-bottom: 60px;
  box-shadow: var(--shadow);
}

.header::after {
  content: '';
  position: absolute;
  bottom: -50px;
  left: 0;
  width: 100%;
  height: 100px;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  transform: skewY(-3deg);
  z-index: -1;
}

.header h1 {
  font-size: 2.8rem;
  margin-bottom: 15px;
  text-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

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

.nav {
  display: flex;
  justify-content: center;
  background: rgba(255,255,255,0.1);
  backdrop-filter: blur(10px);
  padding: 15px;
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav a {
  color: white;
  text-decoration: none;
  margin: 0 15px;
  padding: 8px 16px;
  border-radius: var(--radius);
  transition: var(--transition);
  font-weight: 500;
}

.nav a:hover {
  background: rgba(255,255,255,0.2);
}

.notice {
  background: rgba(255,255,255,0.9);
  color: var(--dark);
  padding: 15px;
  border-radius: var(--radius);
  margin: 30px auto;
  max-width: 800px;
  text-align: center;
  box-shadow: var(--shadow);
  font-weight: 500;
}

.article-container {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 40px;
  margin: 40px 0;
}

article {
  background: white;
  padding: 40px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

article h2 {
  color: var(--primary);
  margin-bottom: 25px;
  font-size: 1.8rem;
  position: relative;
  padding-bottom: 10px;
}

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

article h3 {
  color: var(--secondary);
  margin: 30px 0 15px;
  font-size: 1.4rem;
}

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

pre {
  background: #282c34;
  color: #abb2bf;
  padding: 20px;
  border-radius: var(--radius);
  overflow-x: auto;
  margin: 25px 0;
  box-shadow: var(--shadow);
  font-family: 'Fira Code', monospace;
  font-size: 0.95rem;
}

code {
  font-family: 'Fira Code', monospace;
  background: rgba(0,198,255,0.1);
  color: var(--accent);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.9rem;
}

.sidebar {
  position: sticky;
  top: 100px;
  align-self: start;
}

.sidebar-card {
  background: white;
  border-radius: var(--radius);
  padding: 25px;
  margin-bottom: 30px;
  box-shadow: var(--shadow);
}

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

.sidebar-card ul {
  list-style: none;
}

.sidebar-card li {
  margin-bottom: 10px;
}

.sidebar-card a {
  color: var(--secondary);
  text-decoration: none;
  transition: var(--transition);
  display: block;
  padding: 8px 0;
  border-bottom: 1px solid rgba(0,0,0,0.05);
}

.sidebar-card a:hover {
  color: var(--accent);
  padding-left: 10px;
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: 20px;
  margin: 30px 0;
}

.image-card {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
  aspect-ratio: 1/1;
}

.image-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(0,0,0,0.15);
}

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

.button {
  display: inline-block;
  background: linear-gradient(45deg, var(--accent), var(--secondary));
  color: white;
  padding: 12px 25px;
  border-radius: var(--radius);
  text-decoration: none;
  font-weight: 500;
  margin: 10px 0;
  transition: var(--transition);
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
  border: none;
  cursor: pointer;
}

.button:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 25px rgba(0,0,0,0.2);
}

.footer {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: white;
  padding: 40px 0;
  text-align: center;
  margin-top: 60px;
}

.footer p {
  opacity: 0.8;
  margin-bottom: 15px;
}

@media (max-width: 900px) {
  .article-container {
    grid-template-columns: 1fr;
  }
  
  .sidebar {
    position: static;
  }
}

@media (max-width: 600px) {
  .header h1 {
    font-size: 2rem;
  }
  
  .header p {
    font-size: 1rem;
  }
  
  article {
    padding: 25px;
  }
  
  .image-grid {
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  }
}