:root {
  --primary: #f8f9fa;
  --secondary: #e9ecef;
  --accent: #3498db;
  --highlight: #f39c12;
  --text: #212529;
  --light-text: #6c757d;
}

body {
  font-family: 'Roboto', sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  margin: 0;
  padding: 0;
}

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

.header {
  text-align: center;
  padding: 40px 0;
  background: rgba(255,255,255,0.9);
  border-radius: 16px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.1);
  margin-bottom: 40px;
  position: relative;
  overflow: hidden;
}

.header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--accent), var(--highlight));
  animation: extend 2s ease-out;
}

@keyframes extend {
  from { width: 0; }
  to { width: 100%; }
}

h1, h2, h3, h4 {
  color: var(--text);
  font-weight: 700;
  margin-top: 2em;
}

h2 {
  font-size: 2rem;
  position: relative;
  padding-bottom: 10px;
}

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

h3 {
  font-size: 1.5rem;
  color: var(--accent);
}

p {
  font-size: 1.1rem;
  margin-bottom: 1.5em;
}

.article-content {
  background: white;
  padding: 40px;
  border-radius: 16px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.1);
  margin-bottom: 40px;
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
  margin: 40px 0;
}

.image-card {
  background: white;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.image-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.15);
}

.image-card img {
  width: 100%;
  height: auto;
  display: block;
}

.code-block {
  background: #2d3748;
  color: #e2e8f0;
  padding: 20px;
  border-radius: 8px;
  overflow-x: auto;
  margin: 20px 0;
  font-family: 'Fira Code', monospace;
  font-size: 0.9rem;
}

.code-block code {
  display: block;
  white-space: pre;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
  background: white;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

th, td {
  padding: 15px;
  text-align: left;
  border-bottom: 1px solid #e2e8f0;
}

th {
  background: var(--accent);
  color: white;
  font-weight: 600;
}

tr:hover {
  background: rgba(52, 152, 219, 0.05);
}

.note {
  background: rgba(243, 156, 18, 0.1);
  border-left: 4px solid var(--highlight);
  padding: 20px;
  margin: 20px 0;
  border-radius: 0 8px 8px 0;
}

.note p {
  margin: 0;
}

.sparkle {
  display: inline-block;
  width: 10px;
  height: 10px;
  background-color: var(--highlight);
  border-radius: 50%;
  animation: sparkle 1.5s infinite;
  margin: 0 5px;
}

@keyframes sparkle {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.5); opacity: 0.5; }
}

.footer {
  text-align: center;
  padding: 20px;
  color: var(--light-text);
  font-size: 0.9rem;
}

@media (max-width: 768px) {
  .article-content {
    padding: 20px;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  h3 {
    font-size: 1.2rem;
  }
  
  .image-grid {
    grid-template-columns: 1fr;
  }
}

.scroll-indicator {
  position: fixed;
  top: 0;
  left: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--accent), var(--highlight));
  width: 0;
  z-index: 1000;
  transition: width 0.1s;
}

.navigation {
  display: flex;
  justify-content: center;
  margin-bottom: 30px;
  flex-wrap: wrap;
}

.nav-link {
  margin: 0 10px;
  padding: 10px 15px;
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
  position: relative;
  transition: color 0.3s;
}

.nav-link:hover {
  color: var(--accent);
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width 0.3s;
}

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

.reference-note {
  background: rgba(233, 236, 239, 0.5);
  padding: 15px;
  border-radius: 8px;
  margin: 30px 0;
  text-align: center;
  font-style: italic;
  color: var(--light-text);
}