:root {
    /* Colors - Light Mode */
    --primary-color: #4f46e5;
    --primary-dark: #4338ca;
    --primary-light: #6366f1;
    --secondary-color: #10b981;
    --accent-color: #f59e0b;
    
    /* Background Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --bg-hover: #f3f4f6;
    
    /* Text Colors */
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --text-muted: #9ca3af;
    
    /* Border Colors */
    --border-color: #e5e7eb;
    --border-hover: #d1d5db;
    
    /* Shadow */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-heading: 'Space Grotesk', var(--font-primary);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 350ms ease;
}

/* Dark Mode */
body.dark-mode {
    --bg-primary: #111827;
    --bg-secondary: #1f2937;
    --bg-tertiary: #374151;
    --bg-hover: #374151;
    
    --text-primary: #f9fafb;
    --text-secondary: #d1d5db;
    --text-muted: #9ca3af;
    
    --border-color: #374151;
    --border-hover: #4b5563;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6);
}

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

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

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* Navigation */
.navbar {
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

.nav-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md) 0;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.25rem;
    font-weight: 700;
    font-family: var(--font-heading);
    color: var(--primary-color);
}

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

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

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

.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.icon-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.125rem;
    cursor: pointer;
    padding: var(--spacing-sm);
    border-radius: 0.5rem;
    transition: all var(--transition-fast);
}

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

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.25rem;
    cursor: pointer;
    padding: var(--spacing-sm);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    padding: var(--spacing-2xl) 0;
    text-align: center;
    color: white;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-family: var(--font-heading);
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    opacity: 0.9;
    margin-bottom: var(--spacing-xl);
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: var(--spacing-2xl);
    margin-top: var(--spacing-xl);
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    font-family: var(--font-heading);
}

.stat-label {
    font-size: 0.875rem;
    opacity: 0.8;
    margin-top: var(--spacing-xs);
}

/* Sections */
.section {
    padding: var(--spacing-2xl) 0;
}

.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-xl);
}

.section-title {
    font-family: var(--font-heading);
    font-size: 2rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.section-title i {
    color: var(--primary-color);
}

/* Featured Grid */
.featured-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-xl);
}

.featured-card {
    background-color: var(--bg-primary);
    border-radius: 1rem;
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
    cursor: pointer;
}

.featured-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.featured-image {
    width: 100%;
    height: 240px;
    object-fit: cover;
}

.featured-content {
    padding: var(--spacing-lg);
}

.featured-category {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    margin-bottom: var(--spacing-sm);
}

.featured-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    line-height: 1.3;
    font-family: var(--font-heading);
}

.featured-summary {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.featured-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    font-size: 0.875rem;
    color: var(--text-muted);
}

.featured-author {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.featured-stats {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

/* Filters */
.filters-section {
    background-color: var(--bg-primary);
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
    padding: var(--spacing-lg) 0;
}

.filters-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
}

.filter-group {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.filter-label {
    font-weight: 600;
    color: var(--text-secondary);
}

.filter-buttons {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.filter-btn {
    background-color: var(--bg-tertiary);
    border: 2px solid transparent;
    color: var(--text-secondary);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: 0.5rem;
    cursor: pointer;
    font-weight: 500;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

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

.filter-btn.active {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.filter-select {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: 0.5rem;
    cursor: pointer;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.filter-select:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* View Toggle */
.view-toggle {
    display: flex;
    gap: var(--spacing-xs);
    background-color: var(--bg-tertiary);
    padding: 0.25rem;
    border-radius: 0.5rem;
}

.view-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: 0.375rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.view-btn:hover {
    color: var(--text-primary);
}

.view-btn.active {
    background-color: var(--bg-primary);
    color: var(--primary-color);
    box-shadow: var(--shadow-sm);
}

/* Articles Grid */
.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.articles-grid.list-view {
    grid-template-columns: 1fr;
}

.article-card {
    background-color: var(--bg-primary);
    border-radius: 0.75rem;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
    cursor: pointer;
    display: flex;
    flex-direction: column;
}

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

.list-view .article-card {
    flex-direction: row;
}

.article-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.list-view .article-image {
    width: 280px;
    height: auto;
}

.article-content {
    padding: var(--spacing-lg);
    flex: 1;
    display: flex;
    flex-direction: column;
}

.article-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-sm);
}

.article-category {
    display: inline-block;
    background-color: var(--bg-tertiary);
    color: var(--primary-color);
    padding: 0.25rem 0.625rem;
    border-radius: 0.375rem;
    font-size: 0.75rem;
    font-weight: 600;
}

.bookmark-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.125rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.bookmark-btn:hover,
.bookmark-btn.bookmarked {
    color: var(--accent-color);
}

.article-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    line-height: 1.4;
    font-family: var(--font-heading);
}

.article-summary {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    flex: 1;
    font-size: 0.9375rem;
}

.article-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-md);
}

.tag {
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
    padding: 0.25rem 0.5rem;
    border-radius: 0.25rem;
    font-size: 0.75rem;
}

.article-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: var(--spacing-sm);
    border-top: 1px solid var(--border-color);
    font-size: 0.875rem;
    color: var(--text-muted);
}

.article-author {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.article-stats {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

/* Loading & Empty States */
.loading-spinner {
    text-align: center;
    padding: var(--spacing-2xl);
    color: var(--text-secondary);
}

.loading-spinner i {
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
}

.no-results {
    text-align: center;
    padding: var(--spacing-2xl);
    color: var(--text-secondary);
}

.no-results i {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.5;
}

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

.page-btn {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: 0.5rem;
    cursor: pointer;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.page-btn:hover:not(:disabled) {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.page-btn.active {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.page-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Search Modal */
.search-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 2000;
    padding: var(--spacing-xl);
}

.search-modal.active {
    display: flex;
    align-items: flex-start;
    justify-content: center;
}

.search-modal-content {
    background-color: var(--bg-primary);
    border-radius: 1rem;
    box-shadow: var(--shadow-xl);
    width: 100%;
    max-width: 700px;
    margin-top: 10vh;
    max-height: 70vh;
    display: flex;
    flex-direction: column;
}

.search-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
}

.search-input {
    flex: 1;
    background: none;
    border: none;
    font-size: 1.125rem;
    color: var(--text-primary);
    outline: none;
}

.close-search {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.25rem;
    cursor: pointer;
    transition: color var(--transition-fast);
}

.close-search:hover {
    color: var(--text-primary);
}

.search-results {
    padding: var(--spacing-lg);
    overflow-y: auto;
    max-height: calc(70vh - 80px);
}

.search-placeholder {
    text-align: center;
    color: var(--text-muted);
    padding: var(--spacing-xl);
}

.search-result-item {
    padding: var(--spacing-md);
    border-radius: 0.5rem;
    cursor: pointer;
    transition: background-color var(--transition-fast);
    margin-bottom: var(--spacing-sm);
}

.search-result-item:hover {
    background-color: var(--bg-hover);
}

.search-result-title {
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.search-result-meta {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* Newsletter */
.newsletter-section {
    background-color: var(--bg-primary);
}

.newsletter-card {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    border-radius: 1rem;
    padding: var(--spacing-2xl);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-xl);
    color: white;
}

.newsletter-title {
    font-family: var(--font-heading);
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.newsletter-text {
    opacity: 0.9;
}

.newsletter-form {
    display: flex;
    gap: var(--spacing-sm);
    min-width: 400px;
}

.newsletter-input {
    flex: 1;
    padding: var(--spacing-md);
    border: none;
    border-radius: 0.5rem;
    font-size: 1rem;
}

.newsletter-btn {
    background-color: white;
    color: var(--primary-color);
    border: none;
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: 0.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.newsletter-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

/* Footer */
.footer {
    background-color: var(--bg-primary);
    border-top: 1px solid var(--border-color);
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-xl);
}

.footer-title {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.footer-text {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.social-links {
    display: flex;
    gap: var(--spacing-sm);
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
    border-radius: 0.5rem;
    text-decoration: none;
    transition: all var(--transition-fast);
}

.social-link:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

.footer-subtitle {
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: var(--spacing-sm);
}

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

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

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
}

/* Responsive Design */
@media (max-width: 1024px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .newsletter-card {
        flex-direction: column;
        text-align: center;
    }
    
    .newsletter-form {
        min-width: 100%;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .hero-stats {
        gap: var(--spacing-lg);
    }
    
    .stat-number {
        font-size: 1.5rem;
    }
    
    .featured-grid {
        grid-template-columns: 1fr;
    }
    
    .filters-container {
        flex-direction: column;
        align-items: stretch;
    }
    
    .filter-group {
        flex-direction: column;
        align-items: stretch;
    }
    
    .filter-buttons {
        width: 100%;
    }
    
    .filter-btn {
        flex: 1;
        justify-content: center;
    }
    
    .articles-grid {
        grid-template-columns: 1fr;
    }
    
    .list-view .article-card {
        flex-direction: column;
    }
    
    .list-view .article-image {
        width: 100%;
        height: 200px;
    }
    
    .newsletter-form {
        flex-direction: column;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
    
    .search-modal {
        padding: var(--spacing-md);
    }
    
    .search-modal-content {
        margin-top: 5vh;
    }
}

/* Utility Classes */
.btn-primary {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: 0.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-1px);
}

.btn-secondary {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    border: none;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: 0.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    text-decoration: none;
}

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