/* Variables */
:root {
    /* Colors */
    --color-primary: #4f46e5;
    --color-primary-dark: #4338ca;
    --color-primary-light: #6366f1;
    --color-background: #f9fafb;
    --color-surface: #ffffff;
    --color-gray-100: #f3f4f6;
    --color-gray-200: #e5e7eb;
    --color-gray-400: #9ca3af;
    --color-gray-500: #6b7280;
    --color-gray-700: #374151;
    --color-gray-900: #111827;

    /* Typography */
    --font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-family-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    
    /* Layout */
    --max-width-content: 85ch;
    --spacing-1: 0.25rem;
    --spacing-2: 0.5rem;
    --spacing-3: 0.75rem;
    --spacing-4: 1rem;
    --spacing-6: 1.5rem;
    --spacing-8: 2rem;
    --spacing-12: 3rem;
    
    /* Effects */
    --radius-sm: 0.25rem;
    --radius-base: 0.375rem;
    --radius-lg: 0.5rem;
    --radius-full: 9999px;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-base: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --transition-base: 0.2s ease;
}

/* Reset */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* Base styles */
html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    line-height: 1.5;
    color: var(--color-gray-900);
    background-color: var(--color-background);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Navigation */
.main-nav {
    background-color: var(--color-surface);
    box-shadow: var(--shadow-base);
    position: sticky;
    top: 0;
    z-index: 10;
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.nav-brand {
    display: flex;
    align-items: center;
}

.site-title {
    font-size: 1.5rem;
    font-weight: bold;
    text-decoration: none;
    color: #333;
}

.nav-actions {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.nav-link {
    color: #64748b;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
}

.nav-link:hover {
    color: #2563eb;
}

.nav-button {
    padding: 0.5rem 1rem;
    border-radius: 0.375rem;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.2s ease;
}

.nav-button-primary {
    background-color: #2563eb;
    color: white;
}

.nav-button-primary:hover {
    background-color: #1d4ed8;
}

.nav-button-secondary {
    background-color: transparent;
    color: #2563eb;
    border: 1px solid #2563eb;
}

.nav-button-secondary:hover {
    background-color: #f8fafc;
}

/* Main Content */
.main-content {
    flex-grow: 1;
    padding: 1rem 0;
}

/* Article List */
.article-list {
    display: grid;
    gap: var(--spacing-8);
}

.article-card {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-base);
    padding: var(--spacing-6);
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

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

.article-title {
    color: var(--color-gray-900);
    font-size: var(--font-size-2xl);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-4);
    text-decoration: none;
    display: block;
    transition: color var(--transition-base);
}

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

.article-excerpt {
    color: var(--color-gray-700);
    margin-bottom: var(--spacing-4);
    text-align: justify;
}

/* Tags */
.tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-2);
}

.tag {
    background-color: var(--color-gray-100);
    color: var(--color-gray-700);
    font-size: var(--font-size-sm);
    padding: var(--spacing-1) var(--spacing-3);
    border-radius: var(--radius-full);
    text-decoration: none;
    transition: all var(--transition-base);
}

.tag:hover,
.tag:focus {
    background-color: var(--color-gray-200);
    color: var(--color-gray-900);
}

/* Article Container */
.article-container {
    background-color: var(--color-surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    margin: var(--spacing-8) auto;
    max-width: var(--max-width-content);
    overflow: hidden;
}

.article-header {
    padding: var(--spacing-8);
    border-bottom: 1px solid var(--color-gray-200);
}

.article-content {
    padding: var(--spacing-8);
}

/* Typography */
.prose {
    font-size: var(--font-size-lg);
    line-height: 1.75;
    text-align: justify;
}

.prose > * + * {
    margin-top: var(--spacing-6);
}

.prose h1 {
    font-size: var(--font-size-4xl);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: var(--spacing-6);
}

.prose h2 {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    line-height: 1.3;
    margin-top: var(--spacing-12);
    margin-bottom: var(--spacing-4);
}

.prose h3 {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    line-height: 1.4;
    margin-top: var(--spacing-8);
    margin-bottom: var(--spacing-3);
}

.prose p {
    margin-bottom: var(--spacing-6);
    color: var(--color-gray-700);
    text-align: justify;
    hyphens: none;
}

.prose a {
    color: var(--color-primary);
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: all var(--transition-base);
}

.prose a:hover,
.prose a:focus {
    color: var(--color-primary-dark);
    border-bottom-color: var(--color-primary-dark);
}

.prose img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-base);
    margin: var(--spacing-8) 0;
}

.prose blockquote {
    border-left: 4px solid var(--color-gray-200);
    padding-left: var(--spacing-4);
    color: var(--color-gray-500);
    font-style: italic;
    margin: var(--spacing-6) 0;
}

.prose code {
    font-family: var(--font-family-mono);
    font-size: 0.9em;
    background-color: var(--color-gray-100);
    padding: var(--spacing-1) var(--spacing-2);
    border-radius: var(--radius-sm);
}

.prose pre {
    background-color: var(--color-gray-900);
    color: var(--color-gray-100);
    padding: var(--spacing-4);
    border-radius: var(--radius-base);
    overflow-x: auto;
    margin: var(--spacing-6) 0;
}

.prose pre code {
    background: none;
    padding: 0;
    font-size: 0.9em;
    line-height: 1.7;
}

/* Lists */
.prose ul,
.prose ol {
    margin: var(--spacing-4) 0;
    padding-left: var(--spacing-8);
}

.prose li {
    margin: var(--spacing-2) 0;
    padding-left: var(--spacing-2);
}

.prose li::marker {
    color: var(--color-gray-500);
}

/* Add nested list styles */
.prose ul ul,
.prose ul ol,
.prose ol ul,
.prose ol ol {
    margin: var(--spacing-2) 0;
}

.prose ul {
    list-style-type: disc;
}

.prose ul ul {
    list-style-type: circle;
}

.prose ul ul ul {
    list-style-type: square;
}

.prose ol {
    list-style-type: decimal;
}

.prose ol ol {
    list-style-type: lower-alpha;
}

.prose ol ol ol {
    list-style-type: lower-roman;
}

/* Tables */
.prose table {
    width: 100%;
    border-collapse: collapse;
    margin: var(--spacing-6) 0;
    box-shadow: var(--shadow-sm);
    border-radius: var(--radius-base);
    overflow: hidden;
}

.prose th,
.prose td {
    padding: var(--spacing-3);
    text-align: left;
}

.prose th {
    background-color: var(--color-gray-100);
    font-weight: 600;
}

.prose td {
    background-color: var(--color-surface);
}

.prose tr:not(:last-child) td {
    border-bottom: 1px solid var(--color-gray-100);
}

/* Footer */
.main-footer {
    background-color: #f8fafc;
    padding: 2rem 0;
    margin-top: 4rem;
}

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

.social-links {
    display: flex;
    gap: 1rem;
}

.social-link {
    color: #64748b;
    text-decoration: none;
}

.social-link:hover {
    color: #2563eb;
}

.copyright {
    color: #64748b;
}

/* Pagination */
.pagination {
    display: flex;
    justify-content: space-between;
    margin-top: var(--spacing-8);
    padding-top: var(--spacing-4);
    border-top: 1px solid var(--color-gray-200);
}

.pagination-link {
    color: var(--color-gray-500);
    font-size: var(--font-size-sm);
    text-decoration: none;
    padding: var(--spacing-2) 0;
    transition: all var(--transition-base);
}

.pagination-link:hover,
.pagination-link:focus {
    color: var(--color-gray-900);
    border-top: 2px solid var(--color-gray-300);
    margin-top: -2px;
}

/* Focus styles for accessibility */
:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    :root {
        --spacing-8: 1.5rem;
        --spacing-12: 2rem;
    }

    .container {
        padding: 0 var(--spacing-4);
    }

    .site-title {
        font-size: 1.25rem;
    }

    .nav-link {
        font-size: 0.875rem;
    }

    .nav-button {
        padding: 0.375rem 0.75rem;
        font-size: 0.875rem;
    }

    .nav-actions {
        gap: 1rem;
    }
    
    .article-card {
        border-radius: var(--radius-base);
    }
    
    .article-container {
        margin: var(--spacing-4);
        border-radius: var(--radius-base);
    }
    
    .article-header,
    .article-content {
        padding: var(--spacing-6);
    }
    
    .prose {
        font-size: var(--font-size-base);
    }
    
    .prose h1 {
        font-size: var(--font-size-2xl);
    }
    
    .prose h2 {
        font-size: var(--font-size-xl);
    }
    
    .prose h3 {
        font-size: var(--font-size-lg);
    }

    .article-title {
        font-size: var(--font-size-lg);
    }

    h1.article-title {
        font-size: var(--font-size-xl);
        line-height: 1.3;
    }

    a.article-title {
        font-size: var(--font-size-lg);
        line-height: 1.4;
    }
}

@media (min-width: 768px) {
    .footer-content {
        flex-direction: row;
        justify-content: space-between;
    }
    
    .social-links {
        order: 2;
    }
    
    .copyright {
        order: 1;
    }
}

/* Accessibility */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: #2563eb;
    color: white;
    padding: 8px;
    z-index: 100;
}

.skip-link:focus {
    top: 0;
}

/* Article Styles */
.article {
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid #e2e8f0;
}

.article:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.article-title {
    font-size: 1.875rem;
    font-weight: bold;
    margin-bottom: 1rem;
}

.article-title a {
    color: #1e293b;
    text-decoration: none;
}

.article-title a:hover {
    color: #2563eb;
}

.article-meta {
    color: #64748b;
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

.article-content {
    color: #334155;
    line-height: 1.6;
}

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

.article-content a {
    color: #2563eb;
    text-decoration: none;
}

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

.article-tags {
    margin-top: 1.5rem;
}

.article-tags a {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background-color: #f1f5f9;
    color: #64748b;
    border-radius: 9999px;
    font-size: 0.875rem;
    text-decoration: none;
    margin-right: 0.5rem;
    margin-bottom: 0.5rem;
}

.article-tags a:hover {
    background-color: #e2e8f0;
    color: #2563eb;
}

.language-selector {
    margin-right: 1rem;
}

.language-selector select {
    padding: 0.5rem;
    border: 1px solid #ddd;
    border-radius: 4px;
    background-color: white;
    font-size: 0.9rem;
}

.language-selector select:focus {
    outline: none;
    border-color: #007bff;
    box-shadow: 0 0 0 2px rgba(0,123,255,0.25);
}