:root {
    --primary-color: #2563eb;
    --text-color: #1f2937;
    --text-secondary: #6b7280;
    --bg-color: #ffffff;
    --bg-secondary: #f9fafb;
    --border-color: #e5e7eb;
    --max-width: 800px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.7;
    color: var(--text-color);
    background: var(--bg-color);
}

header {
    background: var(--bg-color);
    border-bottom: 1px solid var(--border-color);
    padding: 2rem 1.5rem;
    margin-bottom: 3rem;
}

.header-content {
    max-width: var(--max-width);
    margin: 0 auto;
}

.site-title {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-color);
    text-decoration: none;
    display: inline-block;
    margin-bottom: 0.5rem;
}

.site-description {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

main {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1.5rem 4rem;
}

.article-list {
    list-style: none;
}

.article-item {
    margin-bottom: 3rem;
    padding-bottom: 3rem;
    border-bottom: 1px solid var(--border-color);
}

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

.article-meta {
    display: flex;
    gap: 1rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

.article-title {
    font-size: 1.75rem;
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: 0.75rem;
}

.article-title a {
    color: var(--text-color);
    text-decoration: none;
}

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

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

.read-more {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
}

.read-more:hover {
    text-decoration: underline;
}

.categories {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-top: 0.75rem;
}

.category-tag {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: 0.375rem;
    font-size: 0.8125rem;
    text-decoration: none;
}

/* Article Page Styles */
.article-header {
    margin-bottom: 2.5rem;
}

.article-header .article-title {
    font-size: 2.25rem;
    margin-bottom: 1rem;
}

.article-content {
    font-size: 1.0625rem;
    line-height: 1.8;
}

.article-content h2 {
    font-size: 1.75rem;
    font-weight: 700;
    margin: 2.5rem 0 1rem;
    color: var(--text-color);
}

.article-content h3 {
    font-size: 1.375rem;
    font-weight: 600;
    margin: 2rem 0 0.75rem;
    color: var(--text-color);
}

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

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

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

.article-content a {
    color: var(--primary-color);
    text-decoration: none;
}

.article-content a:hover {
    text-decoration: underline;
}

.article-content img {
    max-width: 100%;
    height: auto;
    margin: 2rem 0;
    border-radius: 0.5rem;
}

.article-content figure {
    margin: 2rem 0;
}

.article-content blockquote {
    border-left: 4px solid var(--primary-color);
    padding-left: 1.5rem;
    margin: 2rem 0;
    font-style: italic;
    color: var(--text-secondary);
}

.article-content code {
    background: var(--bg-secondary);
    padding: 0.2rem 0.4rem;
    border-radius: 0.25rem;
    font-size: 0.9em;
    font-family: 'Courier New', monospace;
}

.article-content pre {
    background: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: 0.5rem;
    overflow-x: auto;
    margin: 1.5rem 0;
}

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

.back-link {
    display: inline-block;
    color: var(--text-secondary);
    text-decoration: none;
    margin-bottom: 2rem;
    font-size: 0.95rem;
}

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

footer {
    max-width: var(--max-width);
    margin: 4rem auto 0;
    padding: 2rem 1.5rem;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

@media (max-width: 640px) {
    .article-header .article-title {
        font-size: 1.75rem;
    }
    
    .article-title {
        font-size: 1.5rem;
    }
    
    .article-content h2 {
        font-size: 1.5rem;
    }
    
    .article-content h3 {
        font-size: 1.25rem;
    }
}