:root {
  --primary: #1e40af;
  --primary-light: #3b82f6;
  --primary-dark: #1e3a8a;
  --secondary: #0f766e;
  --accent: #f59e0b;
  --text-dark: #1f2937;
  --text-light: #6b7280;
  --bg-light: #f9fafb;
  --bg-white: #ffffff;
  --border: #e5e7eb;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px 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);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-dark);
  background-color: var(--bg-light);
}

main {
  flex: 1;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1rem;
}

h1 {
  font-size: 2.5rem;
}

h2 {
  font-size: 2rem;
  color: var(--primary-dark);
}

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

h4 {
  font-size: 1.25rem;
}

p {
  margin-bottom: 1rem;
  color: var(--text-light);
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.3s ease, text-decoration 0.3s ease;
}

a:hover {
  color: var(--primary-light);
  text-decoration: underline;
}

/* Navigation */
nav.main-menu {
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
  color: white;
  padding: 1.5rem 0;
  box-shadow: var(--shadow-lg);
  position: sticky;
  top: 0;
  z-index: 100;
}

nav.main-menu .nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

nav.main-menu h1 {
  margin: 0;
  font-size: 1.75rem;
  color: white;
}

nav.main-menu ul {
  list-style: none;
  display: flex;
  gap: 2rem;
}

nav.main-menu a {
  color: white;
  font-weight: 500;
  transition: opacity 0.3s ease;
}

nav.main-menu a:hover {
  opacity: 0.8;
  text-decoration: none;
}

/* Dropdown Navigation */
nav.main-menu .nav-dropdown {
  position: relative;
}

nav.main-menu .nav-dropdown-toggle::after {
  content: ' ▼';
  font-size: 0.75rem;
  opacity: 0.7;
}

nav.main-menu .nav-submenu {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  background: var(--primary-dark);
  border-radius: 6px;
  box-shadow: var(--shadow-lg);
  min-width: 240px;
  list-style: none;
  padding: 0.5rem 0;
  margin-top: 0.5rem;
  z-index: 1000;
}

nav.main-menu .nav-dropdown:hover .nav-submenu,
nav.main-menu .nav-dropdown:focus-within .nav-submenu {
  display: block;
}

nav.main-menu .nav-submenu li {
  padding: 0;
}

nav.main-menu .nav-submenu a {
  display: block;
  padding: 0.75rem 1.5rem;
  white-space: nowrap;
  font-weight: 400;
  font-size: 0.95rem;
}

nav.main-menu .nav-submenu a:hover {
  background-color: var(--primary);
  border-radius: 0;
}

/* Main Content */
main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 3rem 2rem;
}

section {
  margin-bottom: 4rem;
}

section > h2,
section > h3 {
  margin-bottom: 2rem;
  text-align: center;
}

/* Hero Section */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: white;
  padding: 4rem 2rem;
  border-radius: 12px;
  text-align: center;
  margin-bottom: 3rem;
}

.hero h2 {
  color: white;
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.hero p {
  color: rgba(255, 255, 255, 0.95);
  font-size: 1.1rem;
  margin: 0;
}

/* Articles Grid */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.article-card {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 2rem;
  transition: all 0.3s ease;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
}

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

.article-card h3,
.article-card h4 {
  color: var(--primary-dark);
  margin-bottom: 0.5rem;
}

.article-card .date {
  font-size: 0.875rem;
  color: var(--text-light);
  font-weight: 500;
  margin-bottom: 1rem;
}

.article-card p {
  flex: 1;
  margin-bottom: 1.5rem;
}

.article-card a,
.read-more {
  color: var(--primary);
  font-weight: 600;
  display: inline-block;
  transition: all 0.3s ease;
  align-self: flex-start;
}

.article-card a:hover,
.read-more:hover {
  color: var(--primary-light);
  transform: translateX(4px);
  text-decoration: none;
}

/* Article Detail */
.article-detail {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 3rem;
  box-shadow: var(--shadow);
  margin-top: 2rem;
}

.article-full {
  max-width: 800px;
  margin: 0 auto;
}

.article-full h2 {
  margin-bottom: 1rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid var(--primary-light);
}

.article-full .date {
  color: var(--text-light);
  font-style: italic;
  margin-bottom: 2rem;
  display: block;
}

.article-full p {
  margin-bottom: 1.5rem;
  line-height: 1.8;
}

.article-error {
  background-color: #fee2e2;
  color: #991b1b;
  padding: 1.5rem;
  border-radius: 8px;
  border-left: 4px solid #dc2626;
}

/* Footer */
footer {
  background-color: var(--text-dark);
  color: white;
  text-align: center;
  padding: 2rem;
  margin-top: 4rem;
}

footer p {
  color: white;
  margin: 0;
}

/* Responsive Design */
@media (max-width: 768px) {
  nav.main-menu .nav-container {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }

  nav.main-menu ul {
    gap: 1rem;
    justify-content: center;
  }

  nav.main-menu h1 {
    font-size: 1.5rem;
  }

  h1 {
    font-size: 2rem;
  }

  h2 {
    font-size: 1.5rem;
  }

  .hero {
    padding: 2.5rem 1rem;
  }

  .hero h2 {
    font-size: 1.75rem;
  }

  main {
    padding: 2rem 1rem;
  }

  .articles-grid {
    grid-template-columns: 1fr;
  }

  .article-detail {
    padding: 1.5rem;
  }

  .article-full {
    padding: 0;
  }
}