/* CSS Custom Properties for Theming */
:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --accent-color: #f093fb;
    --accent-secondary: #f5576c;
    --text-primary: #333;
    --text-secondary: #555;
    --text-muted: #666;
    --bg-primary: #fafafa;
    --bg-secondary: #f8f9fa;
    --bg-card: #ffffff;
    --bg-dark: #2d3748;
    --border-color: #e0e0e0;
    --shadow-light: rgba(0,0,0,0.08);
    --shadow-medium: rgba(0,0,0,0.1);
    --shadow-heavy: rgba(0,0,0,0.15);
    --gradient-primary: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    --gradient-accent: linear-gradient(135deg, var(--accent-color) 0%, var(--accent-secondary) 100%);
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --border-radius-lg: 16px;
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.7;
    color: var(--text-primary);
    background: var(--bg-primary);
    font-feature-settings: 'kern' 1, 'liga' 1;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 clamp(1rem, 4vw, 2rem);
}

/* Typography Scale */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

h1 { font-size: clamp(2rem, 5vw, 2.5rem); }
h2 { font-size: clamp(1.5rem, 4vw, 1.8rem); }
h3 { font-size: clamp(1.2rem, 3vw, 1.3rem); }
h4 { font-size: clamp(1.1rem, 2.5vw, 1.2rem); }

p {
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Main Content */
main {
    min-height: calc(100vh - 200px);
    padding: clamp(2rem, 5vw, 4rem) 0;
}

.content {
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    box-shadow:
        0 4px 20px var(--shadow-light),
        0 1px 3px var(--shadow-medium);
    overflow: hidden;
    margin: 2rem auto;
    max-width: min(800px, 90vw);
    position: relative;
}

.content::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-primary);
}

/* Article Header */
.article-header {
    background: var(--gradient-accent);
    color: white;
    padding: clamp(2rem, 8vw, 3rem) clamp(1rem, 4vw, 2rem);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.article-header::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    animation: pulse 4s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); opacity: 0.5; }
    50% { transform: scale(1.05); opacity: 0.8; }
}

.article-header h1 {
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
    position: relative;
    z-index: 1;
}

.meta {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    font-size: 0.9rem;
    opacity: 0.9;
    position: relative;
    z-index: 1;
}

.category {
    background: rgba(255,255,255,0.2);
    backdrop-filter: blur(10px);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-weight: 500;
    border: 1px solid rgba(255,255,255,0.3);
}

/* Article Content */
.article-content {
    padding: clamp(2rem, 6vw, 3rem) clamp(1rem, 4vw, 2rem);
}

.article-content p {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
    text-align: justify;
    hyphens: auto;
}

.article-content h2 {
    font-size: clamp(1.4rem, 3.5vw, 1.8rem);
    font-weight: 600;
    margin: 3rem 0 1.5rem 0;
    color: var(--text-primary);
    position: relative;
    scroll-margin-top: 2rem;
}

.article-content h2::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 60px;
    height: 4px;
    background: var(--gradient-primary);
    border-radius: 2px;
    transition: width var(--transition-normal);
}

.article-content h2:hover::after {
    width: 80px;
}

.article-content h3 {
    font-size: clamp(1.1rem, 2.5vw, 1.3rem);
    font-weight: 600;
    margin: 2rem 0 1rem 0;
    color: var(--text-primary);
}

.article-content ul {
    margin: 1.5rem 0 2rem 1.5rem;
    padding-left: 1rem;
}

.article-content li {
    margin-bottom: 0.75rem;
    position: relative;
    padding-left: 0.5rem;
    color: var(--text-secondary);
}

.article-content li::before {
    content: '▸';
    position: absolute;
    left: -1.5rem;
    top: 0.1em;
    color: var(--primary-color);
    font-weight: bold;
    font-size: 1.2em;
}

/* Performance Metrics Cards */
.performance-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin: 3rem 0;
}

.card {
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
    padding: 2.5rem 2rem;
    text-align: center;
    border-left: 4px solid var(--primary-color);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
    cursor: pointer;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.1), transparent);
    transition: left 0.5s ease;
}

.card:hover::before {
    left: 100%;
}

.card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow:
        0 12px 30px var(--shadow-medium),
        0 4px 12px var(--shadow-light);
    border-left-color: var(--secondary-color);
}

.card h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
    font-weight: 600;
}

.card .metric {
    font-size: clamp(2rem, 8vw, 2.5rem);
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-variant-numeric: tabular-nums;
    transition: color var(--transition-fast);
}

.card:hover .metric {
    color: var(--secondary-color);
}

.card p {
    color: var(--text-muted);
    font-size: 0.95rem;
    font-weight: 500;
}

/* Code Blocks */
code {
    background: var(--bg-secondary);
    color: var(--primary-color);
    padding: 0.25rem 0.5rem;
    border-radius: 6px;
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Code', 'Droid Sans Mono', 'Source Code Pro', monospace;
    font-size: 0.9em;
    font-weight: 500;
    border: 1px solid var(--border-color);
    transition: all var(--transition-fast);
}

code:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

pre {
    background: var(--bg-dark);
    color: #e2e8f0;
    padding: 1.5rem;
    border-radius: var(--border-radius);
    overflow-x: auto;
    margin: 1.5rem 0;
    position: relative;
    border: 1px solid #4a5568;
    box-shadow: 0 4px 12px var(--shadow-heavy);
}

pre::before {
    content: '';
    position: absolute;
    top: 12px;
    left: 12px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: #ff5f57;
    box-shadow: 20px 0 0 #ffbd2e, 40px 0 0 #28ca42;
}

pre code {
    background: none;
    padding: 0;
    border: none;
    color: inherit;
    font-size: 0.95em;
    line-height: 1.6;
}

/* Footer */
footer {
    background: var(--bg-dark);
    color: #e2e8f0;
    padding: 2.5rem 0 1.5rem 0;
    text-align: center;
    margin-top: 5rem;
    position: relative;
}

footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, #4a5568, transparent);
}

footer p {
    margin-bottom: 0.75rem;
    opacity: 0.8;
    font-size: 0.95rem;
}

footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
}

footer a:hover {
    color: #90cdf4;
    text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .tools-grid {
        grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    }

    .performance-cards {
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    }
}

@media (max-width: 768px) {
    .article-header h1 {
        font-size: clamp(1.8rem, 6vw, 2.2rem);
    }

    .article-content {
        padding: 2rem 1.5rem;
    }

    .performance-cards {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .tools-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .table-of-contents {
        position: static;
        padding: 1.5rem;
        margin: 2rem 0;
    }

    .cta ul {
        flex-direction: column;
        gap: 1rem;
        align-items: center;
    }

    .budget-row {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
        padding: 1rem;
    }

    .action-items {
        padding: 2rem 1.5rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }

    .article-header {
        padding: 2rem 1rem;
    }

    .article-header h1 {
        font-size: clamp(1.6rem, 8vw, 2rem);
    }

    .meta {
        flex-direction: column;
        gap: 0.5rem;
    }

    .card {
        padding: 2rem 1.5rem;
    }

    .tool-card {
        padding: 1.5rem;
    }

    pre {
        padding: 1rem;
        font-size: 0.85em;
    }

    .cta {
        padding: 2rem 1.5rem;
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --primary-color: #0066cc;
        --secondary-color: #004499;
        --text-primary: #000000;
        --text-secondary: #333333;
        --bg-card: #ffffff;
        --border-color: #000000;
    }
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    :root {
        --text-primary: #e2e8f0;
        --text-secondary: #a0aec0;
        --text-muted: #718096;
        --bg-primary: #1a202c;
        --bg-secondary: #2d3748;
        --bg-card: #1a202c;
        --bg-dark: #0f1419;
        --border-color: #4a5568;
        --shadow-light: rgba(0,0,0,0.3);
        --shadow-medium: rgba(0,0,0,0.4);
        --shadow-heavy: rgba(0,0,0,0.5);
    }

    .content {
        background: var(--bg-card);
        color: var(--text-primary);
    }

    .card {
        background: var(--bg-secondary);
    }

    .tool-card {
        background: var(--bg-card);
        border-color: var(--border-color);
    }
}

/* Table of Contents */
.table-of-contents {
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
    padding: clamp(1.5rem, 4vw, 2rem);
    margin: 3rem 0;
    border-left: 4px solid var(--primary-color);
    position: sticky;
    top: 2rem;
    box-shadow: 0 2px 12px var(--shadow-light);
}

.table-of-contents h2 {
    margin-bottom: 1.5rem;
    font-size: 1.4rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.table-of-contents h2::before {
    content: '📋';
    font-size: 1.2em;
}

.table-of-contents ul {
    list-style: none;
    padding: 0;
}

.table-of-contents li {
    margin-bottom: 0.75rem;
    position: relative;
    padding-left: 1rem;
}

.table-of-contents li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.5rem;
    width: 6px;
    height: 6px;
    background: var(--primary-color);
    border-radius: 50%;
    transition: transform var(--transition-fast);
}

.table-of-contents li:hover::before {
    transform: scale(1.5);
}

.table-of-contents a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: all var(--transition-fast);
    font-weight: 500;
    display: block;
    padding: 0.25rem 0;
    border-radius: 4px;
}

.table-of-contents a:hover,
.table-of-contents a.active {
    color: var(--primary-color);
    background: rgba(102, 126, 234, 0.1);
    transform: translateX(4px);
    font-weight: 600;
}

/* Tools Grid */
.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
    margin: 3rem 0;
}

.tool-card {
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 2rem;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.tool-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(102, 126, 234, 0.05), transparent);
    transition: left 0.6s ease;
}

.tool-card:hover::before {
    left: 100%;
}

.tool-card:hover {
    border-color: var(--primary-color);
    box-shadow: 0 8px 25px var(--shadow-medium);
    transform: translateY(-4px);
}

.tool-card h4 {
    margin-bottom: 0.75rem;
    color: var(--text-primary);
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.tool-card h4::before {
    content: '🔧';
    font-size: 1.1em;
}

.tool-card p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-size: 1rem;
    line-height: 1.6;
}

.tool-card a,
.tool-card code {
    color: var(--primary-color);
    font-weight: 600;
    text-decoration: none;
    transition: all var(--transition-fast);
    padding: 0.5rem 1rem;
    border-radius: 6px;
    background: rgba(102, 126, 234, 0.1);
    display: inline-block;
}

.tool-card a:hover,
.tool-card code:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

/* Performance Budget Table */
.budget-table {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: 0 4px 16px var(--shadow-light);
    margin: 3rem 0;
    border: 1px solid var(--border-color);
}

.budget-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 2rem;
    border-bottom: 1px solid var(--border-color);
    transition: background var(--transition-fast);
}

.budget-row:last-child {
    border-bottom: none;
}

.budget-row:nth-child(even) {
    background: var(--bg-secondary);
}

.budget-row:hover {
    background: rgba(102, 126, 234, 0.05);
    transform: scale(1.01);
}

.metric-name {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 1rem;
}

.budget-value {
    color: var(--primary-color);
    font-weight: 600;
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', monospace;
    background: rgba(102, 126, 234, 0.1);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.9rem;
}

/* Action Items */
.action-items {
    background: linear-gradient(135deg, #e3f2fd 0%, #f3e5f5 100%);
    border-radius: var(--border-radius);
    padding: 2.5rem;
    margin: 3rem 0;
    border-left: 4px solid var(--primary-color);
    position: relative;
}

.action-items::before {
    content: '✅';
    position: absolute;
    top: 1rem;
    right: 1rem;
    font-size: 1.5rem;
    opacity: 0.6;
}

.action-items h3 {
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    font-size: 1.3rem;
}

.action-items ol {
    padding-left: 1.5rem;
    counter-reset: step-counter;
}

.action-items li {
    margin-bottom: 1rem;
    color: var(--text-secondary);
    position: relative;
    padding-left: 2rem;
    counter-increment: step-counter;
}

.action-items li::before {
    content: counter(step-counter);
    position: absolute;
    left: 0;
    top: 0;
    background: var(--primary-color);
    color: white;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    font-weight: 600;
}

/* Call to Action */
.cta {
    background: var(--gradient-primary);
    color: white;
    border-radius: var(--border-radius-lg);
    padding: 3rem 2rem;
    margin: 3rem 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.cta::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    animation: cta-glow 6s ease-in-out infinite;
}

@keyframes cta-glow {
    0%, 100% { transform: scale(1) rotate(0deg); opacity: 0.3; }
    50% { transform: scale(1.1) rotate(180deg); opacity: 0.6; }
}

.cta p {
    margin-bottom: 2rem;
    font-size: 1.2rem;
    font-weight: 500;
    position: relative;
    z-index: 1;
}

.cta ul {
    list-style: none;
    padding: 0;
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
    position: relative;
    z-index: 1;
}

.cta a {
    color: white;
    text-decoration: none;
    font-weight: 600;
    padding: 0.75rem 1.5rem;
    border-radius: 25px;
    background: rgba(255,255,255,0.2);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.3);
    transition: all var(--transition-normal);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.cta a::before {
    content: '🔗';
    font-size: 1.1em;
}

.cta a:hover {
    background: white;
    color: var(--primary-color);
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.2);
}

/* Performance Optimizations */
img {
    max-width: 100%;
    height: auto;
    display: block;
    border-radius: var(--border-radius-sm);
}

/* Loading animations for better perceived performance */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.article-content section {
    animation: fadeInUp 0.6s ease-out;
    animation-fill-mode: both;
}

.article-content section:nth-child(1) { animation-delay: 0.1s; }
.article-content section:nth-child(2) { animation-delay: 0.2s; }
.article-content section:nth-child(3) { animation-delay: 0.3s; }
.article-content section:nth-child(4) { animation-delay: 0.4s; }
.article-content section:nth-child(5) { animation-delay: 0.5s; }
.article-content section:nth-child(6) { animation-delay: 0.6s; }
.article-content section:nth-child(7) { animation-delay: 0.7s; }
.article-content section:nth-child(8) { animation-delay: 0.8s; }

/* Smooth transitions for interactive elements */
* {
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

/* Skip link for accessibility */
.skip-link {
    position: absolute;
    top: -40px;
    left: 6px;
    background: var(--primary-color);
    color: white;
    padding: 8px 16px;
    text-decoration: none;
    border-radius: 4px;
    z-index: 1000;
    transition: top var(--transition-fast);
    font-weight: 500;
}

.skip-link:focus {
    top: 6px;
}

/* Print styles */
@media print {
    * {
        background: transparent !important;
        color: black !important;
        box-shadow: none !important;
        text-shadow: none !important;
    }

    a, a:visited {
        text-decoration: underline;
    }

    .no-print {
        display: none;
    }

    .content {
        box-shadow: none;
        border: 1px solid #ccc;
    }
}