/* ==================== CSS Reset & Base Styles ==================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Color Palette */
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --secondary-color: #10b981;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --border-color: #e5e7eb;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    
    /* Typography */
    --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-heading: 'Georgia', serif;
    
    /* Spacing */
    --container-width: 1200px;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
}

body {
    font-family: var(--font-primary);
    color: var(--text-primary);
    line-height: 1.6;
    background-color: var(--bg-light);
}

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

/* ==================== Header ==================== */
.site-header {
    background: var(--bg-white);
    border-bottom: 1px solid var(--border-color);
    padding: var(--spacing-md) 0;
    box-shadow: var(--shadow);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.site-title {
    font-family: var(--font-heading);
    font-size: 1.75rem;
    font-weight: 700;
}

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

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

.main-nav {
    display: flex;
    gap: var(--spacing-md);
}

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

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

/* ==================== Ad Containers ==================== */
.ad-container {
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    margin: var(--spacing-md) 0;
    display: flex;
    justify-content: center;
    align-items: center;
}

.ad-placeholder {
    padding: var(--spacing-md);
    color: var(--text-secondary);
    font-size: 0.875rem;
    text-align: center;
}

.ad-header, .ad-footer {
    min-height: 90px;
}

.ad-sidebar {
    min-height: 250px;
    margin-bottom: var(--spacing-md);
}

.ad-in-content {
    min-height: 100px;
    margin: var(--spacing-lg) 0;
}

/* ==================== Main Content Layout ==================== */
.main-content {
    padding: var(--spacing-xl) 0;
}

.content-wrapper {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: var(--spacing-lg);
}

.main-column {
    min-width: 0;
}

/* ==================== Article Cards (List View) ==================== */
.articles-grid {
    display: grid;
    gap: var(--spacing-lg);
}

.article-card {
    background: var(--bg-white);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: var(--spacing-md);
}

.article-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.article-image {
    overflow: hidden;
}

.article-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.article-card:hover .article-image img {
    transform: scale(1.05);
}

.article-content {
    padding: var(--spacing-md);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.article-title {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
    line-height: 1.3;
}

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

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

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

.article-excerpt {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.7;
}

.read-more {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.3s ease;
    align-self: flex-start;
}

.read-more:hover {
    color: var(--primary-dark);
}

/* ==================== Article Detail ==================== */
.article-detail {
    background: var(--bg-white);
    border-radius: 8px;
    padding: var(--spacing-xl);
    box-shadow: var(--shadow);
}

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

.article-detail .article-title {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
    line-height: 1.2;
}

.article-detail .article-meta {
    justify-content: flex-start;
}

.separator {
    color: var(--border-color);
}

.article-featured-image {
    margin-bottom: var(--spacing-lg);
    border-radius: 8px;
    overflow: hidden;
}

.article-featured-image img {
    width: 100%;
    height: auto;
    display: block;
}

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

.article-body h2 {
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    font-size: 1.75rem;
}

.article-body h3 {
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    font-size: 1.5rem;
}

.article-body p {
    margin-bottom: var(--spacing-md);
}

.article-body img {
    max-width: 100%;
    height: auto;
    border-radius: 4px;
    margin: var(--spacing-md) 0;
}

.article-body ul, .article-body ol {
    margin-left: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.article-footer {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
}

.article-tags {
    margin-bottom: var(--spacing-md);
}

.tag {
    display: inline-block;
    background: var(--bg-light);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    margin-right: var(--spacing-xs);
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.btn-back {
    display: inline-block;
    background: var(--primary-color);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    transition: background 0.3s ease;
}

.btn-back:hover {
    background: var(--primary-dark);
}

/* ==================== Pagination ==================== */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-xl);
    padding: var(--spacing-md);
}

.page-link {
    padding: 0.5rem 1rem;
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    color: var(--primary-color);
    text-decoration: none;
    transition: all 0.3s ease;
}

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

.page-current {
    padding: 0.5rem 1rem;
    color: var(--text-secondary);
    font-weight: 600;
}

/* ==================== No Articles ==================== */
.no-articles {
    text-align: center;
    padding: var(--spacing-xl);
    background: var(--bg-white);
    border-radius: 8px;
    color: var(--text-secondary);
}

/* ==================== Footer ==================== */
.site-footer {
    background: var(--text-primary);
    color: white;
    text-align: center;
    padding: var(--spacing-lg) 0;
    margin-top: var(--spacing-xl);
}

/* ==================== Responsive Design ==================== */
@media (max-width: 968px) {
    .content-wrapper {
        grid-template-columns: 1fr;
    }
    
    .sidebar {
        order: -1;
    }
    
    .article-card {
        grid-template-columns: 1fr;
    }
    
    .article-image {
        height: 200px;
    }
}

@media (max-width: 640px) {
    .header-content {
        flex-direction: column;
        gap: var(--spacing-sm);
        text-align: center;
    }
    
    .article-detail .article-title {
        font-size: 1.75rem;
    }
    
    .article-detail {
        padding: var(--spacing-md);
    }
    
    .pagination {
        flex-wrap: wrap;
    }
}