/* CSS Variables for theme switching */
:root {
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --secondary-color: #64748b;
    --accent-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --background: #ffffff;
    --surface: #f8fafc;
    --surface-hover: #f1f5f9;
    --text-primary: #1e293b;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --border: #e2e8f0;
    --border-light: #f1f5f9;
    --shadow: rgba(0, 0, 0, 0.1);
    --shadow-lg: rgba(0, 0, 0, 0.15);
    --code-bg: #f8fafc;
    --sidebar-width: 320px;
    --content-max-width: 900px;
    --border-radius: 12px;
    --border-radius-sm: 8px;
}

[data-theme="dark"] {
    --primary-color: #60a5fa;
    --primary-hover: #3b82f6;
    --secondary-color: #94a3b8;
    --accent-color: #34d399;
    --warning-color: #fbbf24;
    --error-color: #f87171;
    --background: #0f172a;
    --surface: #1e293b;
    --surface-hover: #334155;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #64748b;
    --border: #334155;
    --border-light: #475569;
    --shadow: rgba(0, 0, 0, 0.4);
    --shadow-lg: rgba(0, 0, 0, 0.6);
    --code-bg: #1e293b;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background);
    transition: all 0.3s ease;
}

/* Navigation */
.navbar {
    background: rgba(248, 250, 252, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
}

[data-theme="dark"] .navbar {
    background: rgba(30, 41, 59, 0.8);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.nav-icon {
    font-size: 1.75rem;
}

.nav-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin: 0;
}

.nav-controls {
    display: flex;
    gap: 1rem;
    align-items: center;
}

.btn-primary,
.btn-secondary {
    padding: 0.6rem 1.2rem;
    border: none;
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.2s ease;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

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

.btn-primary:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.btn-secondary {
    background: var(--surface);
    color: var(--text-primary);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background: var(--surface-hover);
    transform: translateY(-1px);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-primary);
    padding: 0.5rem;
}

/* Layout */
.container {
    display: flex;
    margin-top: 80px;
    min-height: calc(100vh - 80px);
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: var(--surface);
    border-right: 1px solid var(--border);
    position: fixed;
    height: calc(100vh - 80px);
    overflow-y: auto;
    z-index: 100;
}

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

.sidebar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.sidebar-header h3 {
    color: var(--text-primary);
    font-size: 1.1rem;
    font-weight: 600;
    margin: 0;
}

.close-sidebar {
    display: none;
    background: none;
    border: none;
    font-size: 1.2rem;
    cursor: pointer;
    color: var(--text-muted);
    padding: 0.25rem;
}

.toc-list {
    list-style: none;
}

.toc-list li {
    margin-bottom: 0.25rem;
}

.toc-list a {
    color: var(--text-secondary);
    text-decoration: none;
    display: block;
    padding: 0.75rem 1rem;
    border-radius: var(--border-radius-sm);
    font-size: 0.9rem;
    transition: all 0.2s ease;
    border-left: 3px solid transparent;
}

.toc-list a:hover {
    background: var(--surface-hover);
    color: var(--primary-color);
    border-left-color: var(--primary-color);
    transform: translateX(4px);
}

.toc-list a.active {
    background: rgba(59, 130, 246, 0.1);
    color: var(--primary-color);
    border-left-color: var(--primary-color);
    font-weight: 500;
}

.sidebar-footer {
    margin-top: 2rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border);
}

.progress-text {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

.progress-bar {
    height: 4px;
    background: var(--border);
    border-radius: 2px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    transition: width 0.3s ease;
    width: 0%;
}

/* Main Content */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    padding: 0;
    max-width: calc(100% - var(--sidebar-width));
}

.content-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #6366f1 100%);
    color: white;
    padding: 4rem 2rem;
    text-align: center;
}

.main-title {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.main-subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
    font-weight: 400;
    max-width: 600px;
    margin: 0 auto;
}

.content-wrapper {
    max-width: var(--content-max-width);
    margin: 0 auto;
    padding: 3rem 2rem;
}

/* Topic Sections */
.topic-section {
    margin-bottom: 4rem;
    background: var(--surface);
    border-radius: var(--border-radius);
    border: 1px solid var(--border);
    box-shadow: 0 4px 6px var(--shadow);
    transition: all 0.3s ease;
    overflow: hidden;
}

.topic-section:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 32px var(--shadow-lg);
}

.topic-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #6366f1 100%);
    color: white;
    padding: 2rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.topic-icon {
    font-size: 2.5rem;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
}

.topic-title {
    font-size: 2rem;
    font-weight: 700;
    margin: 0;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

.topic-content {
    padding: 2.5rem;
}

/* Content Typography */
.content-h3 {
    color: var(--primary-color);
    font-size: 1.4rem;
    margin: 2.5rem 0 1rem 0;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.content-h3::before {
    content: "▶";
    font-size: 0.8em;
    color: var(--accent-color);
}

.content-h4 {
    color: var(--text-primary);
    font-size: 1.2rem;
    margin: 2rem 0 1rem 0;
    font-weight: 600;
}

.content-paragraph {
    margin-bottom: 1.2rem;
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.8;
}

.content-list {
    margin: 1.5rem 0;
    padding-left: 1.5rem;
}

.content-list li {
    margin-bottom: 0.75rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.content-list li::marker {
    color: var(--primary-color);
}

/* Inline Elements */
.inline-code {
    background: var(--code-bg);
    color: var(--primary-color);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Roboto Mono', monospace;
    font-size: 0.9em;
    font-weight: 500;
}

.emoji {
    font-size: 1.1em;
    margin-right: 0.25rem;
}

.emoji.success {
    color: var(--accent-color);
}

.emoji.error {
    color: var(--error-color);
}

.emoji.warning {
    color: var(--warning-color);
}

.emoji.info {
    color: var(--primary-color);
}

/* Tables */
.table-container {
    margin: 2rem 0;
    border-radius: var(--border-radius-sm);
    overflow: hidden;
    border: 1px solid var(--border);
    box-shadow: 0 2px 8px var(--shadow);
}

.content-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--background);
}

.content-table th {
    background: var(--primary-color);
    color: white;
    padding: 1rem 1.5rem;
    text-align: left;
    font-weight: 600;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.content-table td {
    padding: 1rem 1.5rem;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-light);
}

.content-table tr:hover {
    background: var(--surface-hover);
}

.content-table tr:last-child td {
    border-bottom: none;
}

/* Example Boxes */
.example-box {
    margin: 2rem 0;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    border-left: 4px solid;
    position: relative;
    overflow: hidden;
}

.example-box::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, transparent, currentColor, transparent);
    opacity: 0.3;
}

.example-box.success {
    background: rgba(16, 185, 129, 0.05);
    border-left-color: var(--accent-color);
    color: var(--accent-color);
}

.example-box.info {
    background: rgba(59, 130, 246, 0.05);
    border-left-color: var(--primary-color);
    color: var(--primary-color);
}

.example-box.warning {
    background: rgba(245, 158, 11, 0.05);
    border-left-color: var(--warning-color);
    color: var(--warning-color);
}

.example-box.error {
    background: rgba(239, 68, 68, 0.05);
    border-left-color: var(--error-color);
    color: var(--error-color);
}

.example-title {
    font-weight: 600;
    font-size: 1.1rem;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.example-content {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Footer */
.footer {
    background: var(--surface);
    border-top: 1px solid var(--border);
    padding: 3rem 2rem;
    margin-left: var(--sidebar-width);
    text-align: center;
}

.footer-content {
    max-width: var(--content-max-width);
    margin: 0 auto;
    color: var(--text-muted);
}

.footer-content p {
    margin-bottom: 0.5rem;
}

/* Responsive Design */
@media (max-width: 1024px) {
    :root {
        --sidebar-width: 280px;
        --content-max-width: 800px;
    }

    .nav-container {
        padding: 1rem 1.5rem;
    }

    .main-title {
        font-size: 2.5rem;
    }

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

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform 0.3s ease;
        width: 280px;
    }

    .sidebar.open {
        transform: translateX(0);
    }

    .main-content {
        margin-left: 0;
        max-width: 100%;
    }

    .footer {
        margin-left: 0;
    }

    .mobile-menu-btn {
        display: block;
    }

    .close-sidebar {
        display: block;
    }

    .nav-controls {
        gap: 0.5rem;
    }

    .btn-primary,
    .btn-secondary {
        padding: 0.5rem 1rem;
        font-size: 0.85rem;
    }

    .main-title {
        font-size: 2rem;
    }

    .main-subtitle {
        font-size: 1rem;
    }

    .content-header {
        padding: 3rem 1.5rem;
    }

    .content-wrapper {
        padding: 2rem 1rem;
    }

    .topic-section {
        margin-bottom: 2.5rem;
    }

    .topic-header {
        padding: 1.5rem;
        flex-direction: column;
        text-align: center;
        gap: 0.75rem;
    }

    .topic-title {
        font-size: 1.5rem;
    }

    .topic-content {
        padding: 1.5rem;
    }

    .content-table th,
    .content-table td {
        padding: 0.75rem 1rem;
        font-size: 0.9rem;
    }
}

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

    .nav-title {
        font-size: 1.2rem;
    }

    .main-title {
        font-size: 1.75rem;
    }

    .content-wrapper {
        padding: 1.5rem 1rem;
    }

    .topic-header {
        padding: 1.25rem;
    }

    .topic-content {
        padding: 1.25rem;
    }

    .topic-title {
        font-size: 1.3rem;
    }

    .topic-icon {
        font-size: 2rem;
    }
}

/* Scroll behavior */
html {
    scroll-behavior: smooth;
}

/* Custom scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--surface);
}

::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--secondary-color);
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(100%);
    }

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideOut {
    from {
        opacity: 1;
        transform: translateX(0);
    }

    to {
        opacity: 0;
        transform: translateX(100%);
    }
}

.topic-section {
    animation: fadeInUp 0.6s ease-out;
}

/* Focus styles for accessibility */
.btn-primary:focus,
.btn-secondary:focus,
.toc-list a:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Print styles */
@media print {

    .navbar,
    .sidebar,
    .footer {
        display: none;
    }

    .main-content {
        margin-left: 0;
        max-width: 100%;
    }

    .topic-section {
        break-inside: avoid;
        box-shadow: none;
        border: 1px solid #ccc;
    }
}

/* 
Topic Selector */
.topic-selector {
    padding: 0.6rem 1rem;
    border: 1px solid var(--border);
    border-radius: var(--border-radius-sm);
    background: var(--surface);
    color: var(--text-primary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.2s ease;
    min-width: 200px;
}

.topic-selector:hover {
    border-color: var(--primary-color);
}

.topic-selector:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Welcome Screen */
.welcome-screen {
    padding: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.welcome-header {
    text-align: center;
    margin-bottom: 4rem;
}

.welcome-title {
    font-size: 3.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color) 0%, #6366f1 50%, var(--accent-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.welcome-subtitle {
    font-size: 1.3rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto;
    line-height: 1.6;
}

/* Topics Grid */
.topics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-bottom: 4rem;
}

.topic-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--border-radius);
    padding: 2rem;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.topic-card::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.topic-card:hover::before {
    transform: scaleX(1);
}

.topic-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px var(--shadow-lg);
    border-color: var(--primary-color);
}

.topic-card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1.5rem;
}

.topic-card-icon {
    font-size: 3rem;
    filter: drop-shadow(0 2px 4px var(--shadow));
}

.topic-card-badges {
    display: flex;
    gap: 0.5rem;
}

.topic-card-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1rem;
    line-height: 1.3;
}

.topic-card-description {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.topic-card-meta {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.topic-card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

/* Difficulty Badges */
.difficulty-badge {
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.difficulty-beginner {
    background: rgba(16, 185, 129, 0.1);
    color: var(--accent-color);
    border: 1px solid var(--accent-color);
}

.difficulty-intermediate {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning-color);
    border: 1px solid var(--warning-color);
}

.difficulty-advanced {
    background: rgba(239, 68, 68, 0.1);
    color: var(--error-color);
    border: 1px solid var(--error-color);
}

.difficulty-mixed {
    background: rgba(59, 130, 246, 0.1);
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
}

/* Tags */
.tag {
    background: var(--border-light);
    color: var(--text-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

/* Topic Overview in Sidebar */
.topic-overview {
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border);
}

.topic-meta {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.topic-description {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.5;
    margin-bottom: 1rem;
}

.topic-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem;
}

.topic-tags .tag {
    font-size: 0.7rem;
    padding: 0.2rem 0.5rem;
}

/* Platform Info */
.platform-info {
    background: var(--surface);
    border-radius: var(--border-radius);
    padding: 2.5rem;
    border: 1px solid var(--border);
}

.platform-info h3 {
    color: var(--text-primary);
    margin-bottom: 2rem;
    font-size: 1.5rem;
    text-align: center;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.feature {
    text-align: center;
}

.feature-icon {
    font-size: 2.5rem;
    display: block;
    margin-bottom: 1rem;
}

.feature h4 {
    color: var(--text-primary);
    margin-bottom: 0.75rem;
    font-size: 1.1rem;
}

.feature p {
    color: var(--text-secondary);
    line-height: 1.5;
    font-size: 0.9rem;
}

/* Topic Content Screen */
.topic-content-screen {
    min-height: calc(100vh - 80px);
}

/* Topic Header */
.topic-header-content {
    background: linear-gradient(135deg, var(--primary-color) 0%, #6366f1 100%);
    color: white;
    padding: 3rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 2rem;
}

.topic-header-main {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.topic-header-icon {
    font-size: 4rem;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.2));
}

.topic-header-title {
    font-size: 2.5rem;
    font-weight: 800;
    margin: 0 0 0.5rem 0;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.topic-header-description {
    font-size: 1.1rem;
    opacity: 0.9;
    margin: 0;
}

.topic-header-meta {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    align-items: flex-end;
}

/* Section Styling */
.section-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #6366f1 100%);
    color: white;
    padding: 2rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.section-icon {
    font-size: 2.5rem;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    margin: 0;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

.section-content {
    padding: 2.5rem;
}

/* TOC Enhancements */
.toc-number {
    display: inline-block;
    width: 1.5rem;
    height: 1.5rem;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    text-align: center;
    line-height: 1.5rem;
    font-size: 0.8rem;
    font-weight: 600;
    margin-right: 0.75rem;
}

.toc-list a.active .toc-number {
    background: white;
    color: var(--primary-color);
}

/* Responsive Updates */
@media (max-width: 768px) {
    .welcome-title {
        font-size: 2.5rem;
    }

    .welcome-subtitle {
        font-size: 1.1rem;
    }

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

    .topic-card {
        padding: 1.5rem;
    }

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

    .topic-header-content {
        flex-direction: column;
        text-align: center;
        padding: 2rem 1.5rem;
    }

    .topic-header-main {
        flex-direction: column;
        text-align: center;
    }

    .topic-header-title {
        font-size: 2rem;
    }

    .topic-header-meta {
        align-items: center;
    }

    .nav-controls {
        flex-wrap: wrap;
    }

    .topic-selector {
        min-width: 150px;
        order: -1;
        width: 100%;
    }
}

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

    .welcome-title {
        font-size: 2rem;
    }

    .topic-card {
        padding: 1.25rem;
    }

    .topic-card-icon {
        font-size: 2.5rem;
    }

    .topic-header-icon {
        font-size: 3rem;
    }

    .topic-header-title {
        font-size: 1.75rem;
    }
}
* Enhanced Code Block Styling */
.code-block {
    background: var(--code-bg);
    border: 1px solid var(--border);
    border-radius: var(--border-radius-sm);
    margin: 1.5rem 0;
    overflow: hidden;
    box-shadow: 0 2px 8px var(--shadow);
}

.code-block pre {
    margin: 0;
    padding: 1.5rem;
    overflow-x: auto;
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Roboto Mono', 'Courier New', monospace;
    font-size: 0.9rem;
    line-height: 1.5;
    background: transparent;
}

.code-block code {
    background: transparent;
    padding: 0;
    border-radius: 0;
    font-size: inherit;
    color: var(--text-primary);
}

/* Remove old hljs styles - we're using Prism.js now */

/* Practice Section Styling */
.practice-section {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.05) 0%, rgba(16, 185, 129, 0.05) 100%);
    border: 1px solid var(--primary-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin: 2rem 0;
    position: relative;
}

.practice-section::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    border-radius: var(--border-radius) var(--border-radius) 0 0;
}

.practice-title {
    color: var(--primary-color);
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.practice-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.practice-link {
    background: var(--surface);
    border: 1px solid var(--border-light);
    border-radius: var(--border-radius-sm);
    padding: 0.75rem 1rem;
    margin-bottom: 0.5rem;
    transition: all 0.2s ease;
    font-weight: 500;
}

.practice-link:hover {
    background: var(--surface-hover);
    border-color: var(--primary-color);
    transform: translateX(4px);
}

.practice-link:last-child {
    margin-bottom: 0;
}

/* Enhanced Sub-pattern Styling */
.content-h3 {
    background: linear-gradient(135deg, var(--primary-color) 0%, #6366f1 100%);
    color: white;
    padding: 1rem 1.5rem;
    margin: 2rem -2.5rem 1.5rem -2.5rem;
    border-radius: var(--border-radius-sm);
    font-size: 1.3rem;
    font-weight: 600;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

.content-h4 {
    color: var(--primary-color);
    font-size: 1.1rem;
    margin: 1.5rem 0 1rem 0;
    font-weight: 600;
    padding: 0.5rem 0;
    border-bottom: 2px solid var(--primary-color);
    display: inline-block;
}

/* DSA Pattern Specific Styling */
.dsa-pattern-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--border-radius);
    margin-bottom: 3rem;
    overflow: hidden;
    box-shadow: 0 4px 6px var(--shadow);
    transition: all 0.3s ease;
}

.dsa-pattern-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px var(--shadow-lg);
}

/* Algorithm Complexity Badges */
.complexity-badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    margin: 0.25rem;
}

.complexity-o1 {
    background: rgba(16, 185, 129, 0.1);
    color: var(--accent-color);
    border: 1px solid var(--accent-color);
}

.complexity-ologn {
    background: rgba(59, 130, 246, 0.1);
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
}

.complexity-on {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning-color);
    border: 1px solid var(--warning-color);
}

.complexity-on2 {
    background: rgba(239, 68, 68, 0.1);
    color: var(--error-color);
    border: 1px solid var(--error-color);
}

/* Code Output Styling */
.code-output {
    background: var(--background);
    border: 1px solid var(--border);
    border-radius: var(--border-radius-sm);
    padding: 1rem;
    margin: 1rem 0;
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Roboto Mono', monospace;
    font-size: 0.9rem;
    color: var(--accent-color);
}

.code-output::before {
    content: "Output: ";
    color: var(--text-muted);
    font-weight: 600;
}

/* Algorithm Steps */
.algorithm-steps {
    background: var(--surface);
    border-left: 4px solid var(--primary-color);
    padding: 1.5rem;
    margin: 1.5rem 0;
    border-radius: 0 var(--border-radius-sm) var(--border-radius-sm) 0;
}

.algorithm-steps h4 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.algorithm-steps ol {
    padding-left: 1.5rem;
}

.algorithm-steps li {
    margin-bottom: 0.5rem;
    line-height: 1.6;
}

/* Time/Space Complexity Info */
.complexity-info {
    display: flex;
    gap: 1rem;
    margin: 1rem 0;
    flex-wrap: wrap;
}

.complexity-item {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--border-radius-sm);
    padding: 0.75rem 1rem;
    flex: 1;
    min-width: 150px;
}

.complexity-label {
    font-weight: 600;
    color: var(--text-primary);
    display: block;
    margin-bottom: 0.25rem;
}

.complexity-value {
    color: var(--primary-color);
    font-family: 'SF Mono', monospace;
    font-weight: 600;
}

/* Mobile Responsive for DSA Content */
@media (max-width: 768px) {
    .content-h3 {
        margin-left: -1.5rem;
        margin-right: -1.5rem;
        padding: 0.75rem 1rem;
        font-size: 1.1rem;
    }
    
    .code-block pre {
        padding: 1rem;
        font-size: 0.8rem;
    }
    
    .practice-section {
        padding: 1rem;
        margin: 1.5rem 0;
    }
    
    .complexity-info {
        flex-direction: column;
    }
    
    .complexity-item {
        min-width: auto;
    }
}

@media (max-width: 480px) {
    .content-h3 {
        margin-left: -1.25rem;
        margin-right: -1.25rem;
        padding: 0.5rem 0.75rem;
        font-size: 1rem;
    }
    
    .code-block pre {
        padding: 0.75rem;
        font-size: 0.75rem;
    }
    
    .practice-link {
        padding: 0.5rem 0.75rem;
        font-size: 0.9rem;
    }
}/* En
hanced Code Section Styling */
.code-section {
    margin: 2rem 0;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: 0 4px 12px var(--shadow);
    border: 1px solid var(--border);
    background: var(--surface);
}

.code-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #6366f1 100%);
    color: white;
    padding: 0.75rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.9rem;
    font-weight: 600;
}

.code-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.code-language {
    background: rgba(255, 255, 255, 0.2);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

.code-section .code-block {
    background: var(--code-bg);
    margin: 0;
    border: none;
    border-radius: 0;
    box-shadow: none;
}

.code-section .code-block pre {
    margin: 0;
    padding: 1.5rem;
    background: transparent;
    border-radius: 0;
}

/* Different code section types */
.code-section.example-code .code-header {
    background: linear-gradient(135deg, var(--accent-color) 0%, #10b981 100%);
}

.code-section.step-code .code-header {
    background: linear-gradient(135deg, var(--warning-color) 0%, #f59e0b 100%);
}

/* Copy button for code blocks */
.code-section {
    position: relative;
}

.code-section:hover::after {
    content: "📋 Click to copy";
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    background: rgba(0, 0, 0, 0.8);
    color: white;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.7rem;
    pointer-events: none;
    opacity: 0.8;
}

/* Enhanced syntax highlighting */
.code-block code {
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Roboto Mono', 'Courier New', monospace;
    font-size: 0.9rem;
    line-height: 1.6;
}

/* Prism.js Java syntax highlighting */
.token.keyword {
    color: #d73a49;
    font-weight: 700;
}

.token.string {
    color: #032f62;
}

.token.number {
    color: #005cc5;
    font-weight: 600;
}

.token.comment {
    color: #6a737d;
    font-style: italic;
}

.token.class-name {
    color: #6f42c1;
    font-weight: 700;
}

.token.function {
    color: #005cc5;
    font-weight: 700;
}

.token.operator {
    color: #d73a49;
}

.token.punctuation {
    color: #24292e;
}

.token.builtin {
    color: #005cc5;
}

.token.boolean {
    color: #005cc5;
}

/* Dark theme Prism.js syntax highlighting */
[data-theme="dark"] .token.keyword {
    color: #ff7b72;
}

[data-theme="dark"] .token.string {
    color: #a5d6ff;
}

[data-theme="dark"] .token.number {
    color: #79c0ff;
}

[data-theme="dark"] .token.comment {
    color: #8b949e;
}

[data-theme="dark"] .token.class-name {
    color: #d2a8ff;
}

[data-theme="dark"] .token.function {
    color: #79c0ff;
}

[data-theme="dark"] .token.operator {
    color: #ff7b72;
}

[data-theme="dark"] .token.punctuation {
    color: #e1e4e8;
}

[data-theme="dark"] .token.builtin {
    color: #79c0ff;
}

[data-theme="dark"] .token.boolean {
    color: #79c0ff;
}

/* Dynamic Programming specific styling */
.dynamic-programming .section-header {
    background: linear-gradient(135deg, #8b5cf6 0%, #a855f7 100%);
}

.dynamic-programming .topic-header-content {
    background: linear-gradient(135deg, #8b5cf6 0%, #a855f7 100%);
}

/* Algorithm complexity indicators */
.complexity-indicator {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    margin: 1rem 0;
    padding: 0.75rem 1rem;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--border-radius-sm);
    font-size: 0.9rem;
}

.complexity-indicator .complexity-label {
    font-weight: 600;
    color: var(--text-primary);
}

.complexity-indicator .complexity-value {
    font-family: 'SF Mono', monospace;
    background: var(--primary-color);
    color: white;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-weight: 600;
}

/* Step-by-step solution styling */
.solution-steps {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin: 2rem 0;
}

.solution-steps h4 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.solution-steps ol {
    padding-left: 1.5rem;
}

.solution-steps li {
    margin-bottom: 0.75rem;
    line-height: 1.7;
}

/* Mobile responsive improvements for code */
@media (max-width: 768px) {
    .code-header {
        padding: 0.5rem 1rem;
        font-size: 0.8rem;
    }
    
    .code-language {
        font-size: 0.7rem;
        padding: 0.2rem 0.5rem;
    }
    
    .code-section .code-block pre {
        padding: 1rem;
        font-size: 0.8rem;
    }
    
    .code-section:hover::after {
        display: none;
    }
}

@media (max-width: 480px) {
    .code-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
        padding: 0.75rem;
    }
    
    .code-section .code-block pre {
        padding: 0.75rem;
        font-size: 0.75rem;
        overflow-x: auto;
    }
    
    .complexity-indicator {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.25rem;
    }
}

/* Scroll improvements for code blocks */
.code-block pre {
    overflow-x: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--border) var(--surface);
}

.code-block pre::-webkit-scrollbar {
    height: 6px;
}

.code-block pre::-webkit-scrollbar-track {
    background: var(--surface);
}

.code-block pre::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 3px;
}

.code-block pre::-webkit-scrollbar-thumb:hover {
    background: var(--secondary-color);
}

/* Animation for code sections */
.code-section {
    animation: fadeInUp 0.6s ease-out;
}

@keyframes codeHighlight {
    0% { background-color: rgba(59, 130, 246, 0.1); }
    100% { background-color: transparent; }
}

.code-section:target {
    animation: codeHighlight 2s ease-out;
}/* Java 
VS Code Style Java Code Block */
.java-code-block {
    margin: 2.5rem 0;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
    border: 1px solid #3c4043;
    background: #1e1e1e;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
}

.java-code-block .code-header {
    background: #2d2d30;
    border-bottom: 1px solid #3c4043;
    padding: 0;
    display: flex;
    align-items: center;
    position: relative;
}

.java-code-block .code-tabs {
    display: flex;
    align-items: center;
}

.java-code-block .code-tab {
    background: #2d2d30;
    color: #cccccc;
    padding: 8px 16px;
    font-size: 13px;
    font-weight: 400;
    border-right: 1px solid #3c4043;
    position: relative;
    cursor: pointer;
    transition: all 0.2s ease;
}

.java-code-block .code-tab.active {
    background: #1e1e1e;
    color: #ffffff;
}

.java-code-block .code-tab.active::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: #007acc;
}

.java-code-block .code-tab.java {
    color: #f89820;
}

.java-code-block .code-tab.java.active {
    color: #f89820;
}

.java-code-block pre {
    margin: 0;
    padding: 20px;
    background: #1e1e1e;
    overflow-x: auto;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    font-size: 14px;
    line-height: 1.5;
    color: #d4d4d4;
}

.java-code-block code {
    background: transparent;
    padding: 0;
    border-radius: 0;
    font-size: inherit;
    color: inherit;
    white-space: pre;
    display: block;
    font-weight: 400;
}

/* VS Code Java Syntax Highlighting */
.java-code-block .keyword {
    color: #569cd6;
    font-weight: normal;
}

.java-code-block .string {
    color: #ce9178;
}

.java-code-block .comment {
    color: #6a9955;
    font-style: italic;
}

.java-code-block .number {
    color: #b5cea8;
}

.java-code-block .class-name {
    color: #4ec9b0;
    font-weight: normal;
}

.java-code-block .method {
    color: #dcdcaa;
}

.java-code-block .type {
    color: #4ec9b0;
}

.java-code-block .operator {
    color: #d4d4d4;
}

.java-code-block .punctuation {
    color: #d4d4d4;
}

.java-code-block .variable {
    color: #9cdcfe;
}

/* Light theme adjustments */
[data-theme="light"] .java-code-block {
    background: #1e1e1e;
    border-color: #3c4043;
}

[data-theme="light"] .java-code-block .code-header {
    background: #2d2d30;
}

[data-theme="light"] .java-code-block .code-tab {
    background: #2d2d30;
    color: #cccccc;
}

[data-theme="light"] .java-code-block .code-tab.active {
    background: #1e1e1e;
    color: #ffffff;
}

[data-theme="light"] .java-code-block pre {
    background: #1e1e1e;
    color: #d4d4d4;
}

/* Mobile responsive for code blocks */
@media (max-width: 768px) {
    .java-code-block .code-header {
        padding: 0.5rem 1rem;
        font-size: 0.8rem;
    }
    
    .java-code-block pre {
        padding: 1rem;
        font-size: 0.8rem;
    }
}

@media (max-width: 480px) {
    .java-code-block pre {
        padding: 0.75rem;
        font-size: 0.75rem;
    }
}