:root {
  --bg-page: #0f172a;
  --bg-section: #1e293b;
  --bg-card: #283447;
  --text-primary: #e2e8f0;
  --text-secondary: #818cf8; 
  --text-muted: #94a3b8;
  --border-color: #334155;
  --shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
}
@media (prefers-color-scheme: light) {
  :root {
    --bg-page: #f1f5f9;
    --bg-section: #ffffff;
    --bg-card: #f8fafc;
    --text-primary: #1e293b;
    --text-secondary: #4f46e5; 
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
  }
}

html { scroll-behavior: auto; }
body {
  font-family: Arial, sans-serif;
  background-color: var(--bg-page);
  margin: 0;
  padding: 20px;
  color: var(--text-primary);
  transition: background-color 0.3s, color 0.3s;
}
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 15px;
}
h1 {
  text-align: center;
  margin-bottom: 40px;
}

section.category-section {
  background-color: var(--bg-section);
  border-radius: 12px;
  box-shadow: var(--shadow);
  padding: 20px;
  margin-bottom: 30px;
  scroll-margin-top: 20px;
}
section.category-section h2 {
  font-size: 1.8em;
  color: var(--text-secondary);
  border-bottom: 2px solid var(--border-color);
  padding-bottom: 10px;
  margin-top: 0;
  margin-bottom: 20px;
  display: flex; 
  align-items: center; 
  gap: 0.75rem; 
}
.article-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 25px;
}

.article-card {
  background-color: var(--bg-card);
  border-radius: 8px;
  overflow: hidden;
  text-align: center;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  min-height: 250px;
}
.article-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}
.article-card img {
  width: 100%;
  height: 150px;
  object-fit: cover;
  background-color: #333;
}
.article-card .card-content {
  padding: 15px;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}
.article-card .card-content h3 {
  font-size: 1.1em;
  margin: 0;
  line-height: 1.4;
}
.article-card .card-content p {
  font-size: 0.8em;
  color: var(--text-muted);
  margin-top: 5px;
  margin-bottom: 0;
}

#quick-nav {
  position: fixed;
  right: 5px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 100;
  display: flex;
  flex-direction: column;
  gap: 15px;
  padding: 10px;
}
.nav-button {
  cursor: pointer;
  font-size: 1.8em;
  line-height: 1;
  color: var(--text-primary);
  text-decoration: none;
  transition: transform 0.2s, color 0.2s;
  text-shadow: 0 1px 3px rgba(0,0,0,0.4);
}
.nav-button:hover {
  transform: scale(1.2);
  color: var(--text-secondary);
}

.page-footer {
  padding: 20px;
  text-align: center;
  font-size: 14px;
  color: var(--text-muted);
  margin-top: 40px;
}