:root {
  --primary-color: #2563eb;
  --primary-hover: #1d4ed8;
  --secondary-color: #64748b;
  --accent-color: #f59e0b;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --border-color: #e2e8f0;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --radius: 0.5rem;
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

[data-theme="dark"] {
  --primary-color: #3b82f6;
  --primary-hover: #2563eb;
  --secondary-color: #94a3b8;
  --accent-color: #fbbf24;
  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #64748b;
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --border-color: #475569;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.3);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.3), 0 2px 4px -2px rgb(0 0 0 / 0.3);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.3), 0 4px 6px -4px rgb(0 0 0 / 0.3);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

.header {
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0;
  max-width: 1200px;
  margin: 0 auto;
  padding-left: 1rem;
  padding-right: 1rem;
}

.nav-brand {
  font-size: 1.5rem;
  font-weight: 700;
}

.nav-logo {
  text-decoration: none;
  color: var(--primary-color);
  transition: color 0.3s ease;
}

.nav-logo:hover {
  color: var(--primary-hover);
}

.nav-menu {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.nav-link {
  text-decoration: none;
  color: var(--text-secondary);
  font-weight: 500;
  transition: color 0.3s ease;
  position: relative;
}

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

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--primary-color);
  transition: width 0.3s ease;
}

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.theme-toggle {
  background: none;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 0.5rem;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
}

.theme-toggle:hover {
  background-color: var(--bg-secondary);
  border-color: var(--primary-color);
}

.theme-icon {
  font-size: 1.2rem;
  transition: transform 0.3s ease;
}

.theme-toggle:hover .theme-icon {
  transform: rotate(15deg);
}

.main {
  min-height: calc(100vh - 200px);
  padding: 2rem 0;
}

.hero {
  text-align: center;
  padding: 4rem 0;
  background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
  border-radius: var(--radius);
  margin-bottom: 3rem;
}

.hero-title {
  font-size: 3rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

.posts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 2rem;
  margin-bottom: 3rem;
}

.post-card {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-sm);
}

.post-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary-color);
}

.post-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.post-date {
  font-weight: 500;
}

.post-categories {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.category-tag {
  background-color: var(--primary-color);
  color: white;
  padding: 0.25rem 0.75rem;
  border-radius: 1rem;
  font-size: 0.75rem;
  font-weight: 500;
}

.post-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1rem;
  line-height: 1.3;
}

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

.post-title a:hover {
  color: var(--primary-color);
}

.post-excerpt {
  color: var(--text-secondary);
  margin-bottom: 1rem;
  line-height: 1.6;
}

.post-tags {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.tag {
  background-color: var(--bg-secondary);
  color: var(--text-secondary);
  padding: 0.25rem 0.75rem;
  border-radius: 1rem;
  font-size: 0.75rem;
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
}

.tag:hover {
  background-color: var(--primary-color);
  color: white;
  border-color: var(--primary-color);
}

.post {
  max-width: 800px;
  margin: 0 auto;
  background-color: var(--bg-primary);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
}

.post-header {
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

.post-header .post-title {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.post-header .post-meta {
  font-size: 1rem;
}

.post-content {
  font-size: 1.125rem;
  line-height: 1.8;
  color: var(--text-primary);
}

.post-content h1,
.post-content h2,
.post-content h3,
.post-content h4,
.post-content h5,
.post-content h6 {
  margin-top: 2rem;
  margin-bottom: 1rem;
  color: var(--text-primary);
  font-weight: 600;
}

.post-content h1 { font-size: 2rem; }
.post-content h2 { font-size: 1.75rem; }
.post-content h3 { font-size: 1.5rem; }
.post-content h4 { font-size: 1.25rem; }

.post-content p {
  margin-bottom: 1.5rem;
}

.post-content a {
  color: var(--primary-color);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s ease;
}

.post-content a:hover {
  border-bottom-color: var(--primary-color);
}

.post-content code {
  background-color: var(--bg-secondary);
  padding: 0.25rem 0.5rem;
  border-radius: 0.25rem;
  font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
  font-size: 0.875rem;
  border: 1px solid var(--border-color);
}

.post-content pre {
  background-color: var(--bg-secondary);
  padding: 1rem;
  border-radius: var(--radius);
  overflow-x: auto;
  margin: 1.5rem 0;
  border: 1px solid var(--border-color);
}

.post-content pre code {
  background: none;
  padding: 0;
  border: none;
}

.post-content blockquote {
  border-left: 4px solid var(--primary-color);
  padding-left: 1rem;
  margin: 1.5rem 0;
  font-style: italic;
  color: var(--text-secondary);
}

.post-content ul,
.post-content ol {
  margin: 1.5rem 0;
  padding-left: 2rem;
}

.post-content li {
  margin-bottom: 0.5rem;
}

.post-footer {
  margin-top: 2rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border-color);
}

.page {
  max-width: 800px;
  margin: 0 auto;
  background-color: var(--bg-primary);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
}

.page-header {
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

.page-title {
  font-size: 2.5rem;
  font-weight: 600;
  color: var(--text-primary);
}

.page-content {
  font-size: 1.125rem;
  line-height: 1.8;
  color: var(--text-primary);
}

.category-header {
  text-align: center;
  margin-bottom: 3rem;
  padding: 2rem;
  background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
  border-radius: var(--radius);
}

.category-title {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.category-description {
  font-size: 1.25rem;
  color: var(--text-secondary);
}

.category-link {
  text-decoration: none;
  color: var(--primary-color);
  font-weight: 500;
  transition: color 0.3s ease;
}

.category-link:hover {
  color: var(--primary-hover);
}

.error-page {
  text-align: center;
  padding: 4rem 2rem;
  max-width: 600px;
  margin: 0 auto;
}

.error-title {
  font-size: 6rem;
  font-weight: 700;
  color: var(--primary-color);
  margin-bottom: 1rem;
}

.error-message {
  font-size: 1.5rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
}

.error-link {
  display: inline-block;
  background-color: var(--primary-color);
  color: white;
  padding: 1rem 2rem;
  border-radius: var(--radius);
  text-decoration: none;
  font-weight: 500;
  transition: background-color 0.3s ease;
}

.error-link:hover {
  background-color: var(--primary-hover);
}

.footer {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 2rem 0;
  margin-top: 4rem;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-content p {
  color: var(--text-secondary);
  margin: 0;
}

.footer-links {
  display: flex;
  gap: 2rem;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.3s ease;
}

.footer-links a:hover {
  color: var(--primary-color);
}

@media (max-width: 768px) {
  .nav {
    flex-direction: column;
    gap: 1rem;
    padding: 1rem;
  }

  .nav-menu {
    gap: 1rem;
  }

  .hero-title {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  .posts-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .post-card {
    padding: 1rem;
  }

  .post {
    padding: 1rem;
  }

  .post-header .post-title {
    font-size: 2rem;
  }

  .page {
    padding: 1rem;
  }

  .page-title {
    font-size: 2rem;
  }

  .category-title {
    font-size: 2rem;
  }

  .footer-content {
    flex-direction: column;
    text-align: center;
  }

  .footer-links {
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 0.5rem;
  }

  .hero {
    padding: 2rem 1rem;
  }

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

  .post-header .post-title {
    font-size: 1.75rem;
  }

  .page-title {
    font-size: 1.75rem;
  }

  .category-title {
    font-size: 1.75rem;
  }
}