:root {
  --accent-color: #212121;
  --text-primary: #212121;
  --text-secondary: #666;
  --text-muted: #999;
  --bg-primary: #fff;
  --bg-secondary: #f8f8f8;
  --border-color: #e5e5e5;
  --font-serif: Georgia, "Times New Roman", serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --max-width: 720px;
  --line-height: 1.8;
}

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

body {
  font-family: var(--font-serif);
  font-size: 18px;
  line-height: var(--line-height);
  color: var(--text-primary);
  background: var(--bg-primary);
}

a {
  color: var(--accent-color);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s;
}

a:hover {
  border-bottom-color: var(--accent-color);
}

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

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

/* Header */
.site-header {
  padding: 48px 0 32px;
  text-align: center;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 48px;
}

.site-title {
  font-size: 32px;
  font-weight: 400;
  letter-spacing: 2px;
  margin-bottom: 8px;
}

.site-title a {
  border-bottom: none;
}

.site-desc {
  font-family: var(--font-sans);
  font-size: 14px;
  color: var(--text-secondary);
  letter-spacing: 1px;
}

/* Hero Section */
.hero {
  text-align: center;
  padding: 64px 0;
  margin-bottom: 48px;
}

.hero-title {
  font-size: 42px;
  font-weight: 400;
  line-height: 1.3;
  margin-bottom: 16px;
}

.hero-subtitle {
  font-family: var(--font-sans);
  font-size: 16px;
  color: var(--text-secondary);
}

/* Section Title */
.section-title {
  font-size: 12px;
  font-family: var(--font-sans);
  text-transform: uppercase;
  letter-spacing: 3px;
  color: var(--text-muted);
  margin-bottom: 24px;
  text-align: center;
}

/* Article List */
.article-list {
  list-style: none;
}

.article-item {
  padding: 32px 0;
  border-bottom: 1px solid var(--border-color);
}

.article-item:first-child {
  padding-top: 0;
}

.article-item:last-child {
  border-bottom: none;
}

.article-title {
  font-size: 24px;
  font-weight: 400;
  margin-bottom: 12px;
  line-height: 1.4;
}

.article-title a {
  border-bottom: none;
}

.article-title a:hover {
  opacity: 0.7;
}

.article-meta {
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--text-muted);
}

.article-meta span {
  margin-right: 16px;
}

.article-summary {
  margin-top: 16px;
  color: var(--text-secondary);
  font-size: 16px;
  line-height: 1.7;
}

/* Article Detail */
.article-header {
  text-align: center;
  padding: 48px 0 32px;
}

.article-header .article-title {
  font-size: 36px;
  margin-bottom: 16px;
}

.article-featured-image {
  margin: 32px 0;
}

.article-featured-image img {
  width: 100%;
  border-radius: 4px;
}

.article-content {
  font-size: 19px;
  line-height: 1.9;
}

.article-content p {
  margin-bottom: 1.5em;
}

.article-content h2 {
  font-size: 28px;
  font-weight: 400;
  margin: 2em 0 0.8em;
}

.article-content h3 {
  font-size: 22px;
  font-weight: 400;
  margin: 1.8em 0 0.6em;
}

.article-content ul,
.article-content ol {
  margin-bottom: 1.5em;
  padding-left: 2em;
}

.article-content li {
  margin-bottom: 0.5em;
}

.article-content blockquote {
  margin: 2em 0;
  padding: 0 2em;
  border-left: 3px solid var(--accent-color);
  color: var(--text-secondary);
  font-style: italic;
}

/* Category Header */
.category-header {
  text-align: center;
  padding: 48px 0;
  margin-bottom: 32px;
}

.category-title {
  font-size: 36px;
  font-weight: 400;
  margin-bottom: 12px;
}

.category-desc {
  font-family: var(--font-sans);
  font-size: 15px;
  color: var(--text-secondary);
}

/* Grid Layout */
.grid-section {
  margin: 64px 0;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.grid-item h3 {
  font-size: 14px;
  font-family: var(--font-sans);
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.grid-item ul {
  list-style: none;
}

.grid-item li {
  margin-bottom: 12px;
  font-size: 16px;
}

.grid-item a {
  border-bottom: none;
}

.grid-item a:hover {
  opacity: 0.7;
}

/* Footer */
.site-footer {
  text-align: center;
  padding: 48px 0;
  margin-top: 64px;
  border-top: 1px solid var(--border-color);
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--text-muted);
}

.site-footer a {
  color: var(--text-secondary);
}

/* 404 Page */
.error-page {
  text-align: center;
  padding: 120px 0;
}

.error-code {
  font-size: 120px;
  font-weight: 300;
  color: var(--border-color);
  line-height: 1;
  margin-bottom: 24px;
}

.error-title {
  font-size: 24px;
  font-weight: 400;
  margin-bottom: 16px;
}

.error-desc {
  font-family: var(--font-sans);
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

.btn {
  display: inline-block;
  padding: 12px 32px;
  font-family: var(--font-sans);
  font-size: 14px;
  letter-spacing: 1px;
  border: 1px solid var(--accent-color);
  background: transparent;
  color: var(--accent-color);
  cursor: pointer;
  transition: all 0.2s;
}

.btn:hover {
  background: var(--accent-color);
  color: var(--bg-primary);
}

/* Responsive */
@media (max-width: 768px) {
  :root {
    --max-width: 100%;
  }

  body {
    font-size: 17px;
  }

  .hero-title {
    font-size: 28px;
  }

  .article-header .article-title,
  .category-title {
    font-size: 28px;
  }

  .article-content {
    font-size: 17px;
  }

  .grid-3,
  .grid-2 {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .error-code {
    font-size: 80px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 20px;
  }

  .site-header {
    padding: 32px 0 24px;
  }

  .site-title {
    font-size: 24px;
  }

  .hero {
    padding: 40px 0;
  }

  .article-title {
    font-size: 20px;
  }
}