/* CSS Variables for Dark Theme */
:root {
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --bg-tertiary: #3a3a3a;
    --text-primary: #e0e0e0;
    --text-secondary: #b0b0b0;
    --accent-primary: #4a9eff;
    --accent-hover: #6eb3ff;
    --border-color: #404040;
    --sidebar-width: 300px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
}

/* Container Layout */
.container {
    display: flex;
    min-height: 100vh;
}

/* Sidebar Styles */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    z-index: 100;
}

.sidebar-header {
    padding: 2rem 1.5rem 1rem;
    border-bottom: 1px solid var(--border-color);
}

.sidebar-header h1 {
    font-size: 1.5rem;
    color: var(--accent-primary);
    margin-bottom: 0.5rem;
}

.sidebar-header h1 i {
    margin-right: 0.5rem;
}

.tagline {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* Search Container */
.search-container {
    padding: 1rem 1.5rem;
    position: relative;
}

.search-input {
    width: 100%;
    padding: 0.75rem 2.5rem 0.75rem 1rem;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 0.9rem;
    transition: border-color 0.3s;
}

.search-input:focus {
    outline: none;
    border-color: var(--accent-primary);
}

.search-icon {
    position: absolute;
    right: 2.5rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
}

/* Navigation Menu */
.nav-menu {
    flex: 1;
    padding: 1rem 1.5rem;
    overflow-y: auto;
}

.nav-menu h3 {
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

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

.lesson-list li {
    margin-bottom: 0.5rem;
}

.lesson-list a {
    display: block;
    padding: 0.75rem 1rem;
    color: var(--text-primary);
    text-decoration: none;
    border-radius: 6px;
    transition: all 0.3s;
}

.lesson-list a:hover {
    background-color: var(--bg-tertiary);
    color: var(--accent-primary);
    transform: translateX(4px);
}

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

/* GitHub Links */
.github-links {
    padding: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.github-link {
    display: block;
    padding: 0.75rem 1rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    text-decoration: none;
    border-radius: 6px;
    transition: all 0.3s;
    border: 1px solid var(--border-color);
}

.github-link:hover {
    background-color: var(--bg-tertiary);
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

.github-link i {
    margin-right: 0.5rem;
}

/* Main Content Area */
.content {
    margin-left: var(--sidebar-width);
    flex: 1;
    padding: 2rem;
    max-width: 1200px;
}

/* Welcome Content */
.welcome-content {
    animation: fadeIn 0.5s ease-in;
}

.welcome-content h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--accent-primary);
}

.lead {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

/* Feature Grid */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.feature-card {
    background-color: var(--bg-secondary);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: all 0.3s;
}

.feature-card:hover {
    transform: translateY(-4px);
    border-color: var(--accent-primary);
}

.feature-card i {
    font-size: 2.5rem;
    color: var(--accent-primary);
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.feature-card p {
    color: var(--text-secondary);
}

/* Getting Started Section */
.getting-started {
    background-color: var(--bg-secondary);
    padding: 2rem;
    border-radius: 12px;
    border-left: 4px solid var(--accent-primary);
    margin-top: 2rem;
}

.getting-started h2 {
    font-size: 1.75rem;
    margin-bottom: 1rem;
}

.getting-started ol {
    margin-left: 1.5rem;
}

.getting-started li {
    margin-bottom: 0.75rem;
    color: var(--text-secondary);
}

.getting-started a {
    color: var(--accent-primary);
    text-decoration: none;
}

.getting-started a:hover {
    text-decoration: underline;
}

/* Markdown Content Styling */
.markdown-content {
    animation: fadeIn 0.5s ease-in;
}

.markdown-content h1,
.markdown-content h2,
.markdown-content h3,
.markdown-content h4 {
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.markdown-content h1 {
    font-size: 2.5rem;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.markdown-content h2 {
    font-size: 2rem;
    color: var(--accent-primary);
}

.markdown-content h3 {
    font-size: 1.5rem;
}

.markdown-content p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

.markdown-content ul,
.markdown-content ol {
    margin-left: 2rem;
    margin-bottom: 1rem;
}

.markdown-content li {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.markdown-content code {
    background-color: var(--bg-secondary);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    color: var(--accent-primary);
}

.markdown-content pre {
    background-color: var(--bg-secondary);
    padding: 1rem;
    border-radius: 8px;
    overflow-x: auto;
    margin-bottom: 1rem;
    border: 1px solid var(--border-color);
}

.markdown-content pre code {
    background-color: transparent;
    padding: 0;
}

.markdown-content blockquote {
    border-left: 4px solid var(--accent-primary);
    padding-left: 1rem;
    margin: 1rem 0;
    color: var(--text-secondary);
    font-style: italic;
}

.markdown-content table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
}

.markdown-content th,
.markdown-content td {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    text-align: left;
}

.markdown-content th {
    background-color: var(--bg-secondary);
    font-weight: bold;
}

.markdown-content img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    margin: 1rem 0;
}

.markdown-content a {
    color: var(--accent-primary);
    text-decoration: none;
}

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

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Mobile Menu Toggle */
.menu-toggle {
    display: none;
    position: fixed;
    top: 1rem;
    left: 1rem;
    z-index: 200;
    padding: 0.5rem 0.75rem;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    border-radius: 6px;
    cursor: pointer;
    font-size: 1.25rem;
    box-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

.menu-toggle:hover {
    background-color: var(--bg-tertiary);
    color: var(--accent-primary);
}

/* Responsive Design */
@media (max-width: 768px) {
    .menu-toggle {
        display: block;
    }

    .sidebar {
        width: 280px;
        position: fixed;
        top: 0;
        left: 0;
        height: 100vh;
        transform: translateX(-100%);
        transition: transform 0.3s ease-in-out;
        box-shadow: 4px 0 12px rgba(0,0,0,0.3);
    }
    
    .sidebar.active {
        transform: translateX(0);
    }
    
    .content {
        margin-left: 0;
        padding: 4rem 1rem 1rem;
    }
    
    .feature-grid {
        grid-template-columns: 1fr;
    }
}

/* Loading State */
.loading {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
}

.loading i {
    font-size: 2rem;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

/* Error State */
.error {
    background-color: rgba(244, 67, 54, 0.1);
    border: 1px solid rgba(244, 67, 54, 0.3);
    padding: 1rem;
    border-radius: 8px;
    color: #ff6b6b;
    margin: 1rem 0;
}

/* Table of Contents Section */
.toc-section {
    margin-top: 3rem;
    animation: fadeIn 0.5s ease-in;
}

.toc-section h2 {
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.toc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.toc-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    transition: all 0.3s;
}

.toc-card:hover {
    transform: translateY(-4px);
    border-color: var(--accent-primary);
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

.toc-card h3 {
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.toc-card a {
    color: var(--accent-primary);
    text-decoration: none;
    font-weight: bold;
}

.toc-card ul {
    list-style: none;
    margin-top: 1rem;
}

.toc-card li {
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* Make category header clickable in sidebar */
.category-header a {
    color: var(--text-secondary); /* Keep it subtle or match header style */
    text-decoration: none;
    display: block;
    width: 100%;
}

.category-header a:hover {
    color: var(--accent-primary);
}

/* Collapsible sections using details/summary */
.markdown-content details {
    margin: 1rem 0;
    padding: 1rem;
    background-color: var(--bg-secondary);
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.markdown-content details[open] {
    padding-bottom: 0.5rem;
}

.markdown-content summary {
    cursor: pointer;
    font-weight: 600;
    color: var(--text-primary);
    padding: 0.5rem;
    margin: -0.5rem;
    border-radius: 6px;
    transition: background-color 0.2s;
    list-style: none;
}

.markdown-content summary::-webkit-details-marker {
    display: none;
}

.markdown-content summary::before {
    content: '▶ ';
    display: inline-block;
    transition: transform 0.2s;
    color: var(--accent-primary);
}

.markdown-content details[open] summary::before {
    transform: rotate(90deg);
}

.markdown-content summary:hover {
    background-color: var(--bg-tertiary);
}

.markdown-content details > *:not(summary) {
    margin-top: 1rem;
}

/* Ensure proper text wrapping in nested lists */
.markdown-content ul ul,
.markdown-content ol ol,
.markdown-content ul ol,
.markdown-content ol ul {
    margin-left: 1.5rem;
    margin-top: 0.5rem;
    margin-bottom: 0.5rem;
}

.markdown-content li {
    word-wrap: break-word;
    overflow-wrap: break-word;
    white-space: normal;
}

/* Ensure content doesn't overflow */
.markdown-content {
    word-wrap: break-word;
    overflow-wrap: break-word;
}