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

:root {
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --secondary: #10b981;
    --accent: #f59e0b;
    --bg: #0f172a;
    --bg-light: #1e293b;
    --bg-lighter: #334155;
    --text: #f1f5f9;
    --text-dim: #94a3b8;
    --border: #475569;
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    --shadow: rgba(0, 0, 0, 0.3);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
}

code, pre {
    font-family: 'Fira Code', monospace;
}

/* Sidebar Navigation */
.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    width: 280px;
    height: 100vh;
    background: var(--bg-light);
    border-right: 1px solid var(--border);
    padding: 2rem 0;
    display: flex;
    flex-direction: column;
    z-index: 100;
}

.logo {
    padding: 0 2rem 2rem;
    border-bottom: 1px solid var(--border);
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.subtitle {
    color: var(--text-dim);
    font-size: 0.875rem;
}

.nav-menu {
    list-style: none;
    padding: 1.5rem 0;
    flex: 1;
}

.nav-menu li {
    margin: 0.25rem 0;
}

.nav-menu a {
    display: block;
    padding: 0.75rem 2rem;
    color: var(--text-dim);
    text-decoration: none;
    transition: all 0.2s;
    border-left: 3px solid transparent;
}

.nav-menu a:hover {
    color: var(--text);
    background: rgba(37, 99, 235, 0.1);
    border-left-color: var(--primary);
}

.nav-menu a.active {
    color: var(--primary);
    background: rgba(37, 99, 235, 0.15);
    border-left-color: var(--primary);
    font-weight: 500;
}

.nav-footer {
    padding: 1.5rem 2rem;
    border-top: 1px solid var(--border);
}

.version {
    margin-top: 1rem;
    font-size: 0.75rem;
    color: var(--text-dim);
}

/* Main Content */
.content {
    margin-left: 280px;
    padding: 3rem 4rem;
    max-width: 1400px;
}

.section {
    display: none;
    animation: fadeIn 0.5s ease-in;
}

.section.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Hero Section */
.hero {
    margin-bottom: 4rem;
    text-align: center;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, #2563eb, #10b981, #f59e0b);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-dim);
    max-width: 800px;
    margin: 0 auto;
}

.fade-in {
    animation: fadeIn 0.8s ease-out;
}

.fade-in-delay {
    animation: fadeIn 0.8s ease-out 0.2s both;
}

.fade-in-delay-2 {
    animation: fadeIn 0.8s ease-out 0.4s both;
}

.fade-in-delay-3 {
    animation: fadeIn 0.8s ease-out 0.6s both;
}

/* Cards */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 4rem;
}

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

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px var(--shadow);
    border-color: var(--primary);
}

.card-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text);
}

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

/* Buttons */
.btn-primary,
.btn-secondary {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.2s;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 16px rgba(37, 99, 235, 0.4);
}

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

.btn-secondary:hover {
    border-color: var(--primary);
    background: rgba(37, 99, 235, 0.1);
}

/* Visualizations */
.architecture-overview,
.pipeline-container,
.bfs-container,
.demo-container {
    background: var(--bg-light);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 2rem;
    margin: 2rem 0;
}

#architecture-diagram,
#pipeline-viz,
#bfs-viz,
#traverse-graph,
#demo-graph-viz {
    width: 100%;
    height: 500px;
    background: var(--bg);
    border-radius: 8px;
    position: relative;
}

/* Code Examples */
.code-example {
    margin: 2rem 0;
    background: var(--bg-light);
    border: 1px solid var(--border);
    border-radius: 12px;
    overflow: hidden;
}

.code-example h3 {
    padding: 1rem 1.5rem;
    background: var(--bg-lighter);
    border-bottom: 1px solid var(--border);
    font-size: 1rem;
}

.code-example pre {
    margin: 0;
    padding: 1.5rem;
    overflow-x: auto;
}

.code-example code {
    font-size: 0.9rem;
    line-height: 1.6;
    color: #a5b4fc;
}

/* Split View */
.split-view {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin: 2rem 0;
}

.algorithm-steps {
    list-style: none;
    counter-reset: step-counter;
}

.algorithm-steps li {
    counter-increment: step-counter;
    position: relative;
    padding: 1.5rem;
    padding-left: 4rem;
    margin-bottom: 1rem;
    background: var(--bg-light);
    border-left: 4px solid var(--primary);
    border-radius: 8px;
}

.algorithm-steps li::before {
    content: counter(step-counter);
    position: absolute;
    left: 1rem;
    top: 1.5rem;
    width: 2rem;
    height: 2rem;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9rem;
}

.algorithm-steps strong {
    display: block;
    color: var(--text);
    margin-bottom: 0.5rem;
}

.algorithm-steps p {
    color: var(--text-dim);
    font-size: 0.9rem;
}

/* BFS Controls */
.bfs-controls {
    display: flex;
    gap: 1rem;
    margin: 1.5rem 0;
    justify-content: center;
}

#bfs-state {
    background: var(--bg);
    border-radius: 8px;
    padding: 1.5rem;
    margin-top: 1.5rem;
    font-family: 'Fira Code', monospace;
    font-size: 0.9rem;
    color: var(--text-dim);
}

/* Demo Container */
.demo-controls {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    align-items: center;
}

.demo-select {
    flex: 1;
    padding: 0.75rem 1rem;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text);
    font-size: 1rem;
}

.demo-split {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
}

.demo-graph,
.demo-results {
    background: var(--bg);
    border-radius: 8px;
    padding: 1.5rem;
}

.demo-graph h4,
.demo-results h4 {
    margin-bottom: 1rem;
    color: var(--primary);
}

#demo-log {
    background: var(--bg-light);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1rem;
    margin-bottom: 1.5rem;
    max-height: 200px;
    overflow-y: auto;
    font-family: 'Fira Code', monospace;
    font-size: 0.85rem;
}

#demo-table {
    overflow-x: auto;
}

#demo-table table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

#demo-table th,
#demo-table td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

#demo-table th {
    background: var(--bg-lighter);
    font-weight: 600;
    color: var(--primary);
}

/* Join Types */
.join-types {
    display: grid;
    gap: 2rem;
    margin: 2rem 0;
}

.join-card {
    background: var(--bg-light);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 2rem;
}

.join-card h3 {
    margin-bottom: 0.5rem;
}

.join-desc {
    color: var(--text-dim);
    margin-bottom: 1.5rem;
}

.join-example {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.join-viz {
    background: var(--bg);
    border-radius: 8px;
    height: 200px;
}

.join-sql pre {
    background: var(--bg);
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1rem;
}

.join-sql code {
    color: #a5b4fc;
    font-size: 0.9rem;
}

/* Comparison Grid */
.comparison-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-top: 2rem;
}

.comparison-item {
    background: var(--bg-light);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 2rem;
}

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

/* Performance Tables */
.perf-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin: 2rem 0;
}

.perf-card {
    background: var(--bg-light);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 2rem;
}

.perf-card h3 {
    margin-bottom: 1.5rem;
    color: var(--primary);
}

.perf-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

.perf-table tr {
    border-bottom: 1px solid var(--border);
}

.perf-table td {
    padding: 0.75rem 0;
}

.perf-table td:nth-child(2) {
    text-align: center;
}

.perf-table code {
    background: var(--bg);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    color: var(--accent);
    font-size: 0.85rem;
}

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

.tip {
    background: var(--bg-light);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.5rem;
    text-align: center;
    transition: all 0.3s;
}

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

.tip-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.tip h4 {
    color: var(--text);
    margin-bottom: 0.5rem;
}

.tip p {
    color: var(--text-dim);
    font-size: 0.9rem;
}

/* Section Intro */
.section-intro {
    font-size: 1.1rem;
    color: var(--text-dim);
    margin-bottom: 2rem;
}

/* Responsive */
@media (max-width: 1024px) {
    .sidebar {
        width: 240px;
    }
    
    .content {
        margin-left: 240px;
        padding: 2rem;
    }
    
    .split-view,
    .demo-split,
    .comparison-grid,
    .perf-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
    }
    
    .content {
        margin-left: 0;
        padding: 1.5rem;
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .card-grid {
        grid-template-columns: 1fr;
    }
}