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

:root {
    /* Modern Color Palette */
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary-color: #8b5cf6;
    --accent-color: #06b6d4;
    --bg-color: #f8fafc;
    --bg-secondary: #f1f5f9;
    --sidebar-bg: #ffffff;
    --card-bg: #ffffff;
    --text-color: #0f172a;
    --text-secondary: #475569;
    --text-light: #64748b;
    --text-muted: #94a3b8;
    --border-color: #e2e8f0;
    --border-light: #f1f5f9;
    --hover-bg: #f8fafc;
    --active-bg: #eff6ff;
    --code-bg: #1e293b;
    --code-text: #e2e8f0;
    --code-accent: #3b82f6;
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    --info: #3b82f6;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    
    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    color: var(--text-color);
    line-height: 1.6;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    overflow: hidden;
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 50%, var(--secondary-color) 100%);
    color: white;
    padding: var(--spacing-xl) var(--spacing-2xl);
    box-shadow: var(--shadow-lg);
    z-index: 100;
    position: relative;
    overflow: hidden;
}

.header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    opacity: 0.1;
    pointer-events: none;
}

.header h1 {
    font-size: 2rem;
    margin-bottom: var(--spacing-lg);
    font-weight: 700;
    letter-spacing: -0.02em;
    position: relative;
    z-index: 1;
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.header h1::before {
    content: '📚';
    font-size: 2.5rem;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
}

.search-container {
    position: relative;
    max-width: 700px;
    z-index: 1;
}

#search-input {
    width: 100%;
    padding: 1rem 1.25rem 1rem 3rem;
    border: none;
    border-radius: var(--radius-lg);
    font-size: 1rem;
    background: rgba(255, 255, 255, 0.98);
    color: var(--text-color);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    position: relative;
}

#search-input::placeholder {
    color: var(--text-muted);
}

#search-input:focus {
    outline: none;
    box-shadow: var(--shadow-xl), 0 0 0 3px rgba(255, 255, 255, 0.3);
    transform: translateY(-1px);
    background: rgba(255, 255, 255, 1);
}

.search-container::before {
    content: '🔍';
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    z-index: 2;
    font-size: 1.25rem;
    pointer-events: none;
}

.search-results {
    position: absolute;
    top: calc(100% + 0.5rem);
    left: 0;
    right: 0;
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    margin-top: var(--spacing-sm);
    max-height: 500px;
    overflow-y: auto;
    z-index: 1000;
    border: 1px solid var(--border-color);
    animation: slideDown var(--transition-base);
    backdrop-filter: blur(10px);
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.search-result-item {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border-light);
    cursor: pointer;
    transition: all var(--transition-base);
    position: relative;
}

.search-result-item::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: var(--primary-color);
    transform: scaleY(0);
    transition: transform var(--transition-base);
}

.search-result-item:hover {
    background: var(--hover-bg);
    padding-left: calc(var(--spacing-lg) + 4px);
}

.search-result-item:hover::before {
    transform: scaleY(1);
}

.search-result-item:last-child {
    border-bottom: none;
}

.search-result-item h4 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
    font-size: 1rem;
}

.search-result-item p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.5;
}

/* Main Layout */
.main-layout {
    display: flex;
    flex: 1;
    overflow: hidden;
}

/* Sidebar */
.sidebar {
    width: 320px;
    background: var(--sidebar-bg);
    border-right: 1px solid var(--border-color);
    overflow-y: auto;
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-sm);
    position: relative;
}

.sidebar::after {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 1px;
    height: 100%;
    background: linear-gradient(to bottom, transparent, var(--border-color), transparent);
}

.nav-section {
    margin-bottom: var(--spacing-2xl);
}

.nav-section:last-child {
    margin-bottom: 0;
}

.nav-section h3 {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-muted);
    margin-bottom: var(--spacing-md);
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

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

.nav-item {
    margin-bottom: var(--spacing-xs);
}

.nav-link {
    display: flex;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-lg);
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: var(--radius);
    transition: all var(--transition-base);
    cursor: pointer;
    border: 1px solid transparent;
    font-weight: 500;
    position: relative;
    overflow: hidden;
}

.nav-link::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: var(--primary-color);
    transform: scaleY(0);
    transition: transform var(--transition-base);
}

.nav-link:hover {
    background: var(--hover-bg);
    color: var(--primary-color);
    transform: translateX(4px);
    border-color: var(--border-light);
}

.nav-link:hover::before {
    transform: scaleY(1);
}

.nav-link.active {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    font-weight: 600;
    box-shadow: var(--shadow-md);
    border-color: var(--primary-dark);
}

.nav-link.active::before {
    display: none;
}

.nav-link.active:hover {
    transform: translateX(0);
    box-shadow: var(--shadow-lg);
}

.nav-link-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    margin-right: var(--spacing-md);
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--text-secondary);
    flex-shrink: 0;
    transition: all var(--transition-base);
}

.nav-link:hover .nav-link-number {
    background: var(--active-bg);
    color: var(--primary-color);
    transform: scale(1.1);
}

.nav-link.active .nav-link-number {
    background: rgba(255, 255, 255, 0.25);
    color: white;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

/* Content Area */
.content {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-2xl);
    background: var(--bg-color);
}

.content-area {
    max-width: 1200px;
    margin: 0 auto;
    animation: fadeIn var(--transition-slow);
}

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

.welcome {
    text-align: center;
    padding: var(--spacing-2xl) var(--spacing-xl);
}

.welcome h2 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--primary-color);
    font-weight: 700;
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.welcome p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-2xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.quick-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: var(--spacing-lg);
    margin: var(--spacing-2xl) 0;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.stat-card {
    background: var(--card-bg);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    text-align: center;
    transition: all var(--transition-base);
    border: 1px solid var(--border-light);
    position: relative;
    overflow: hidden;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transform: scaleX(0);
    transition: transform var(--transition-base);
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--border-color);
}

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

.stat-card h3 {
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-bottom: var(--spacing-md);
    font-weight: 600;
}

.stat-card p {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.getting-started {
    text-align: left;
    max-width: 700px;
    margin: var(--spacing-2xl) auto;
    background: var(--card-bg);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-light);
}

.getting-started h3 {
    margin-bottom: var(--spacing-lg);
    color: var(--primary-color);
    font-size: 1.5rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.getting-started h3::before {
    content: '🚀';
    font-size: 1.75rem;
}

.getting-started ol {
    margin-left: var(--spacing-lg);
    counter-reset: step-counter;
}

.getting-started li {
    margin-bottom: var(--spacing-md);
    color: var(--text-secondary);
    position: relative;
    padding-left: var(--spacing-md);
    line-height: 1.8;
}

.getting-started li::marker {
    color: var(--primary-color);
    font-weight: 700;
}

/* Document Content */
.doc-content {
    background: var(--card-bg);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-light);
    animation: fadeIn var(--transition-slow);
}

.doc-content h1 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-lg);
    color: var(--primary-color);
    border-bottom: 3px solid var(--border-color);
    padding-bottom: var(--spacing-md);
    font-weight: 700;
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    border-image: linear-gradient(90deg, var(--primary-color), var(--secondary-color)) 1;
}

.doc-content h2 {
    font-size: 1.875rem;
    margin-top: var(--spacing-2xl);
    margin-bottom: var(--spacing-md);
    color: var(--text-color);
    font-weight: 700;
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border-light);
}

.doc-content h3 {
    font-size: 1.5rem;
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
    color: var(--text-color);
    font-weight: 600;
}

.doc-content h4 {
    font-size: 1.25rem;
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
    font-weight: 600;
}

.doc-content p {
    margin-bottom: var(--spacing-lg);
    color: var(--text-secondary);
    line-height: 1.8;
    font-size: 1.0625rem;
}

.doc-content ul,
.doc-content ol {
    margin-left: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
}

.doc-content li {
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
    line-height: 1.8;
}

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

.doc-content a:hover {
    border-bottom-color: var(--primary-color);
    color: var(--primary-dark);
}

.doc-content code {
    background: var(--code-bg);
    color: var(--code-text);
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
    font-family: 'Fira Code', 'Courier New', monospace;
    font-size: 0.875rem;
    font-weight: 500;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.doc-content pre {
    background: var(--code-bg);
    color: var(--code-text);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    overflow-x: auto;
    margin: var(--spacing-lg) 0;
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(255, 255, 255, 0.1);
    position: relative;
}

.doc-content pre::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
}

.doc-content pre code {
    background: none;
    padding: 0;
    border: none;
    font-size: 0.9375rem;
    line-height: 1.6;
}

.doc-content blockquote {
    border-left: 4px solid var(--primary-color);
    padding-left: var(--spacing-lg);
    margin: var(--spacing-lg) 0;
    color: var(--text-secondary);
    font-style: italic;
    background: var(--active-bg);
    padding: var(--spacing-lg);
    border-radius: var(--radius);
    border-left-width: 4px;
}

.doc-content table {
    width: 100%;
    border-collapse: collapse;
    margin: var(--spacing-lg) 0;
    box-shadow: var(--shadow);
    border-radius: var(--radius);
    overflow: hidden;
}

.doc-content table th,
.doc-content table td {
    padding: var(--spacing-md);
    text-align: left;
    border-bottom: 1px solid var(--border-light);
}

.doc-content table th {
    background: var(--bg-secondary);
    font-weight: 600;
    color: var(--text-color);
}

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

/* Notebook Content */
.notebook-content {
    background: var(--card-bg);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-light);
    animation: fadeIn var(--transition-slow);
}

.notebook-content h1 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-xl);
    color: var(--primary-color);
    font-weight: 700;
    letter-spacing: -0.02em;
    padding-bottom: var(--spacing-md);
    border-bottom: 3px solid var(--border-color);
}

.notebook-content .cell {
    margin-bottom: var(--spacing-xl);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.notebook-content .cell:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--primary-light);
}

.notebook-content .cell-markdown {
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    line-height: 1.8;
}

.notebook-content .cell-markdown h1,
.notebook-content .cell-markdown h2,
.notebook-content .cell-markdown h3 {
    color: var(--text-color);
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.notebook-content .cell-code {
    background: var(--code-bg);
    color: var(--code-text);
    padding: var(--spacing-lg);
    overflow-x: auto;
    font-family: 'Fira Code', 'Courier New', monospace;
    font-size: 0.9375rem;
    line-height: 1.6;
    position: relative;
}

.notebook-content .cell-code::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
}

.notebook-content .cell-output {
    background: var(--card-bg);
    padding: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
    font-family: 'Fira Code', 'Courier New', monospace;
    font-size: 0.875rem;
    overflow-x: auto;
}

/* Loading States */
.htmx-request {
    opacity: 0.7;
    pointer-events: none;
    position: relative;
}

.htmx-request::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 24px;
    height: 24px;
    margin: -12px 0 0 -12px;
    border: 3px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

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

.loading {
    text-align: center;
    padding: var(--spacing-2xl);
    color: var(--text-secondary);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
}

.loading::before {
    content: '';
    width: 40px;
    height: 40px;
    border: 4px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.error {
    background: linear-gradient(135deg, #fee2e2, #fecaca);
    color: var(--error);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--error);
    margin: var(--spacing-lg) 0;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.error::before {
    content: '⚠️';
    font-size: 1.5rem;
}

/* Responsive */
@media (max-width: 1024px) {
    .sidebar {
        width: 280px;
    }
    
    .header {
        padding: var(--spacing-lg) var(--spacing-xl);
    }
    
    .header h1 {
        font-size: 1.75rem;
    }
    
    .content {
        padding: var(--spacing-xl);
    }
}

@media (max-width: 768px) {
    .main-layout {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        max-height: 300px;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        padding: var(--spacing-lg);
    }
    
    .content {
        padding: var(--spacing-lg);
    }
    
    .header {
        padding: var(--spacing-lg);
    }
    
    .header h1 {
        font-size: 1.5rem;
        margin-bottom: var(--spacing-md);
    }
    
    .welcome h2 {
        font-size: 2rem;
    }
    
    .doc-content,
    .notebook-content {
        padding: var(--spacing-lg);
    }
    
    .quick-stats {
        grid-template-columns: 1fr;
    }
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
    border-radius: var(--radius);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: var(--radius);
    border: 2px solid var(--bg-secondary);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-light);
}

/* Selection */
::selection {
    background: var(--primary-color);
    color: white;
}

::-moz-selection {
    background: var(--primary-color);
    color: white;
}

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

/* Smooth scrolling */
html {
    scroll-behavior: smooth;
}