:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --text-color: #333;
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --border-color: #e5e7eb;
    --footer-bg: #1f2937;
    --footer-text: #d1d5db;
}

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

body {
    font-family: 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.3s;
}

ul {
    list-style: none;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.site-header {
    background: var(--card-bg);
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.site-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo a {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-color);
}

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

.main-nav ul {
    display: flex;
    gap: 30px;
}

.main-nav a {
    font-weight: 500;
    color: #555;
}

.main-nav a:hover, .main-nav a.active {
    color: var(--primary-color);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--secondary-color), var(--primary-color));
    color: white;
    padding: 60px 0;
    text-align: center;
    margin-bottom: 40px;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 15px;
}

.hero p {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* Layout */
.main-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 40px;
    margin-bottom: 60px;
    min-height: 50vh;
}

/* Article List */
.article-list h2 {
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--border-color);
}

.card {
    background: var(--card-bg);
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    margin-bottom: 25px;
    padding: 25px;
    transition: transform 0.2s;
}

.card:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.category-tag {
    background: #e0e7ff;
    color: var(--primary-color);
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
}

.card h3 {
    margin: 10px 0;
    font-size: 1.4rem;
}

.card h3 a:hover {
    color: var(--primary-color);
}

.excerpt {
    color: #666;
    margin-bottom: 15px;
}

.meta {
    font-size: 0.85rem;
    color: #888;
}

.meta span {
    margin-right: 15px;
}

/* Sidebar */
.widget {
    background: var(--card-bg);
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

.widget h3 {
    margin-bottom: 15px;
    font-size: 1.1rem;
}

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.tags a {
    background: #f3f4f6;
    padding: 5px 10px;
    border-radius: 20px;
    font-size: 0.85rem;
    color: #555;
}

.tags a:hover {
    background: var(--primary-color);
    color: white;
}

/* Article Detail Page */
.article-detail {
    background: var(--card-bg);
    padding: 40px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.article-header {
    margin-bottom: 30px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 20px;
}

.article-header h1 {
    font-size: 2.2rem;
    margin-bottom: 15px;
    color: var(--text-color);
}

/* Markdown Content Styling */
.markdown-body {
    font-family: -apple-system,BlinkMacSystemFont,"Segoe UI","Noto Sans",Helvetica,Arial,sans-serif;
    font-size: 16px;
    line-height: 1.8;
}

.markdown-body h2 {
    font-size: 1.8em;
    border-bottom: 1px solid #eaecef;
    padding-bottom: .3em;
    margin-top: 24px;
    margin-bottom: 16px;
}

.markdown-body h3 {
    font-size: 1.5em;
    margin-top: 24px;
    margin-bottom: 16px;
}

.markdown-body p {
    margin-bottom: 16px;
}

.markdown-body code {
    padding: .2em .4em;
    margin: 0;
    font-size: 85%;
    background-color: rgba(27,31,35,.05);
    border-radius: 3px;
}

.markdown-body pre {
    padding: 16px;
    overflow: auto;
    font-size: 85%;
    line-height: 1.45;
    background-color: #f6f8fa;
    border-radius: 6px;
    margin-bottom: 16px;
}

.markdown-body pre code {
    background-color: transparent;
    padding: 0;
}

.markdown-body blockquote {
    padding: 0 1em;
    color: #6a737d;
    border-left: .25em solid #dfe2e5;
    margin: 0 0 16px 0;
}
.markdown-body a {
    color:  #2563eb;
}

/* Footer */
.site-footer {
    background: var(--footer-bg);
    color: var(--footer-text);
    padding: 40px 0 20px;
    margin-top: auto;
}

.footer-columns {
    display: flex;
    justify-content: space-between;
    margin-bottom: 30px;
}

.footer-col h4 {
    color: white;
    margin-bottom: 15px;
}

.link-exchange ul li {
    margin-bottom: 8px;
}

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

.copyright {
    text-align: center;
    border-top: 1px solid #374151;
    padding-top: 20px;
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
    .main-content {
        grid-template-columns: 1fr;
    }
    
    .footer-columns {
        flex-direction: column;
        gap: 30px;
    }
}