:root {
  /* Color Palette - Blue/Slate Theme */
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-soft: #eff6ff;
  
  --text-main: #111827;
  --text-secondary: #4b5563;
  --text-muted: #9ca3af;
  
  --bg-body: #f9fafb;
  --bg-surface: #ffffff;
  --border: #e5e7eb;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  
  /* Layout */
  --max-width: 1200px;
  --header-height: 64px;
  --radius-card: 12px;
  --radius-btn: 8px;
  
  /* Transition */
  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

*, *::before, *::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", "PingFang SC", "Microsoft YaHei", sans-serif;
  background-color: var(--bg-body);
  color: var(--text-main);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
  transition: var(--transition);
}

img {
  max-width: 100%;
  display: block;
}

/* Layout Containers */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* Header & Navigation */
header {
  height: var(--header-height);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 50;
}

.nav {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 8px;
  letter-spacing: -0.02em;
}

.brand span {
  color: var(--primary);
}

.nav-links {
  display: flex;
  gap: 8px;
}

.nav-links a {
  padding: 8px 16px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: 999px;
}

.nav-links a:hover {
  color: var(--primary);
  background: var(--primary-soft);
}

.nav-links a.active {
  color: var(--primary);
  background: var(--primary-soft);
  font-weight: 600;
}

/* Search Bar */
.search {
  position: relative;
  width: 240px;
}

.search input {
  width: 100%;
  padding: 8px 16px 8px 36px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--bg-body);
  color: var(--text-main);
  font-size: 14px;
  transition: var(--transition);
  outline: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%239ca3af'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0z'%3E%3C/path%3E%3C/svg%3E");
  background-size: 16px;
  background-repeat: no-repeat;
  background-position: 12px center;
}

.search input:focus {
  border-color: var(--primary);
  background: var(--bg-surface);
  box-shadow: 0 0 0 3px var(--primary-soft);
}

/* Main Content */
main {
  padding: 40px 0 80px;
}

/* Hero Section */
.hero {
  background: var(--bg-surface);
  padding: 40px;
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-sm);
  margin-bottom: 32px;
  border: 1px solid var(--border);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), #60a5fa);
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 12px;
  background: var(--primary-soft);
  color: var(--primary);
  font-size: 12px;
  font-weight: 600;
  border-radius: 999px;
  margin-bottom: 16px;
}

.hero h1 {
  font-size: 36px;
  line-height: 1.25;
  font-weight: 800;
  margin: 0 0 20px;
  letter-spacing: -0.02em;
  color: var(--text-main);
}

.meta {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  font-size: 14px;
  color: var(--text-secondary);
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 24px;
}

.meta span {
  display: flex;
  align-items: center;
  gap: 6px;
}

.meta strong {
  font-weight: 600;
  color: var(--text-main);
}

.hero p[data-summary] {
  font-size: 18px;
  line-height: 1.7;
  color: var(--text-secondary);
  margin: 0;
}

/* Grid Layout */
.content-layout {
  display: grid;
  grid-template-columns: minmax(0, 2.5fr) 1fr;
  gap: 32px;
  align-items: start;
}

/* Article Styling */
.article {
  background: var(--bg-surface);
  padding: 40px;
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
}

.article section {
  margin-bottom: 40px;
}

.article section:last-child {
  margin-bottom: 0;
}

.article h2 {
  font-size: 24px;
  font-weight: 700;
  margin: 0 0 20px;
  padding-left: 16px;
  border-left: 4px solid var(--primary);
  color: var(--text-main);
}

.article p {
  font-size: 16px;
  color: var(--text-secondary);
  margin-bottom: 16px;
  text-align: justify;
}

/* Article Images */
.image-gallery {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 16px;
  margin: 24px 0;
}

.image-gallery img {
  width: 100%;
  height: 240px;
  object-fit: cover;
  border-radius: var(--radius-btn);
  box-shadow: var(--shadow-md);
  transition: var(--transition);
  cursor: zoom-in;
}

.image-gallery img:hover {
  transform: scale(1.02);
  box-shadow: var(--shadow-lg);
}

/* Sidebar Panels */
aside {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.panel {
  background: var(--bg-surface);
  padding: 24px;
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
}

.panel h3 {
  font-size: 16px;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.05em;
  margin: 0 0 16px;
}

/* Tags */
.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  padding: 6px 14px;
  background: var(--bg-body);
  color: var(--text-secondary);
  border-radius: 6px;
  font-size: 13px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: var(--transition);
}

.tag:hover {
  background: var(--bg-surface);
  border-color: var(--border);
  box-shadow: var(--shadow-sm);
  transform: translateY(-1px);
}

.tag.active {
  background: var(--primary);
  color: #fff;
}

/* Related News */
.related-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.related-item {
  display: block;
  padding: 16px;
  background: var(--bg-body);
  border-radius: var(--radius-btn);
  border: 1px solid transparent;
  transition: var(--transition);
}

.related-item:hover {
  background: var(--bg-surface);
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.related-item h4 {
  margin: 0 0 8px;
  font-size: 15px;
  font-weight: 600;
  color: var(--text-main);
  line-height: 1.4;
}

.related-item span {
  font-size: 12px;
  color: var(--text-muted);
}

/* Footer */
footer {
  text-align: center;
  padding: 40px 0;
  color: var(--text-muted);
  font-size: 14px;
  border-top: 1px solid var(--border);
  margin-top: 60px;
}

/* Responsive */
@media (max-width: 1024px) {
  .content-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .nav {
    flex-direction: column;
    gap: 16px;
    padding: 16px 0;
  }
  
  header {
    height: auto;
  }
  
  .search {
    width: 100%;
  }
  
  .hero {
    padding: 24px;
  }
  
  .hero h1 {
    font-size: 26px;
  }
  
  .article {
    padding: 24px;
  }
  
  .meta {
    gap: 12px;
  }
}

/* Home Page Specific (if reusing styles) */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
  margin-top: 40px;
}

.nav-card {
  background: var(--bg-surface);
  border-radius: var(--radius-card);
  padding: 32px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  height: 100%;
}

.nav-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary);
}

.nav-card h2 {
  font-size: 20px;
  font-weight: 700;
  margin: 0 0 12px;
  color: var(--text-main);
  line-height: 1.4;
}

.card-top {
  margin-bottom: 16px;
}

.nav-card p {
  color: var(--text-secondary);
  font-size: 15px;
  margin: 0 0 24px;
  flex: 1;
  line-height: 1.6;
}

.card-footer {
  margin-top: auto;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  font-weight: 600;
  color: var(--primary);
  font-size: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.card-footer::after {
  content: "→";
  transition: transform 0.2s ease;
}

.nav-card:hover .card-footer::after {
  transform: translateX(4px);
}

.btn-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  background: var(--primary);
  color: #fff;
  font-weight: 600;
  border-radius: var(--radius-btn);
  font-size: 14px;
  transition: var(--transition);
}

.btn-link:hover {
  background: var(--primary-hover);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

/* Empty State */
.empty {
  text-align: center;
  padding: 40px;
  color: var(--text-muted);
  background: var(--bg-body);
  border-radius: var(--radius-card);
  border: 1px dashed var(--border);
}