/* Complete EDA Tutorial Styles - Consistent with Clustering Tutorial */

/* Override global body background for EDA tutorial */
body {
    background: linear-gradient(135deg, var(--dill-green) 0%, var(--aura-indigo) 100%);
    font-family: var(--font-primary);
    margin: 0;
    padding: 0;
    min-height: 100vh;
}

/* Professional Color Palette - Matching Clustering Tutorial */
:root {
    --alpine-oat: #F5EBDC;
    --dill-green: #5B7553;
    --aura-indigo: #4B3F72;
    --butter-yellow: #FFD95B;
    --dark-gray: #2E2E2E;
    --light-gray: #6B7280;
    --white: #FFFFFF;
    
    /* Typography */
    --font-primary: 'Inter', 'Segoe UI', 'Roboto', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'Monaco', 'Cascadia Code', monospace;
    --font-serif: 'Crimson Text', 'Georgia', 'Times New Roman', serif;
    
    /* Legacy EDA variables for compatibility */
    --eda-primary: var(--dill-green);
    --eda-secondary: var(--aura-indigo);
    --eda-success: #4ecdc4;
    --eda-warning: var(--butter-yellow);
    --eda-danger: #ff6b6b;
    --eda-dark: var(--dark-gray);
    --eda-light: var(--alpine-oat);
    --eda-gradient: linear-gradient(135deg, var(--dill-green), var(--aura-indigo));
    --eda-shadow: 0 8px 32px rgba(91, 117, 83, 0.15);
    --eda-border-radius: 12px;
    --eda-transition: all 0.3s ease;
}

/* Header and Navigation Styles - Matching Clustering Tutorial */
.azbn-header {
    position: fixed !important;
    top: 0 !important;
    left: 0 !important;
    width: 100% !important;
    background: rgba(255, 255, 255, 0.95) !important;
    backdrop-filter: blur(10px) !important;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1) !important;
    z-index: 1000 !important;
    border-bottom: 1px solid rgba(91, 117, 83, 0.1) !important;
}

.azbn-nav {
    padding: 1rem 0;
}

.azbn-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.course-link {
    text-decoration: none;
    color: var(--dill-green);
    font-weight: 600;
    font-size: 1.1rem;
    transition: var(--eda-transition);
}

.course-link:hover {
    color: var(--dill-green);
    transform: translateY(-1px);
}

.azbn-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.azbn-links a {
    color: var(--dark-gray);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    transition: var(--eda-transition);
    position: relative;
}

.azbn-links a:hover {
    color: var(--butter-yellow);
    background: rgba(255, 217, 91, 0.2);
    transform: translateY(-1px);
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.4);
}

/* Main Content Area - Matching Clustering Tutorial */
.main-content {
    margin-top: 80px;
    padding: 2rem 0;
    min-height: calc(100vh - 80px);
}

.azbn-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Tutorial Title Styling - High Contrast for Dark Background */
.tutorial-main-title {
    font-size: 3.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 1.5rem;
    color: var(--white);
    text-shadow: 0 4px 8px rgba(0, 0, 0, 0.5);
    line-height: 1.2;
    letter-spacing: -0.02em;
}

.tutorial-subtitle {
    font-size: 1.3rem;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--alpine-oat);
    line-height: 1.6;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
    font-weight: 500;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.4);
}

/* Card and Section Styling - Matching Clustering Tutorial */
.azbn-card {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 8px 32px rgba(91, 117, 83, 0.1);
    border: 1px solid rgba(91, 117, 83, 0.1);
    backdrop-filter: blur(10px);
    transition: var(--eda-transition);
}

.azbn-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 40px rgba(91, 117, 83, 0.15);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--aura-indigo);
    margin-bottom: 1.5rem;
    text-align: center;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.subsection-title {
    font-size: 1.8rem;
    font-weight: 600;
    color: var(--dill-green);
    margin-bottom: 1rem;
    margin-top: 2rem;
}

/* Progress Bar Styling - Matching Clustering Tutorial */
.progress-container {
    margin: 2rem 0;
    text-align: center;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: rgba(91, 117, 83, 0.2);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--butter-yellow), #F4C430);
    border-radius: 4px;
    transition: width 0.3s ease;
    width: 0%;
    box-shadow: 0 0 10px rgba(255, 217, 91, 0.5);
}

.progress-text {
    color: var(--white);
    font-weight: 600;
    font-size: 1rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.4);
}

/* Section Styling */
.section {
    margin: 3rem 0;
}

.section h2 {
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--aura-indigo);
    margin-bottom: 1.5rem;
    text-align: center;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.section h3 {
    font-size: 1.6rem;
    font-weight: 600;
    color: var(--dill-green);
    margin-bottom: 1rem;
    margin-top: 2rem;
}

/* Button Styling - Matching Clustering Tutorial Exactly */
.next-btn, .prev-btn {
    background: linear-gradient(135deg, var(--dill-green), var(--aura-indigo));
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--eda-transition);
    box-shadow: 0 4px 15px rgba(91, 117, 83, 0.3);
}

.next-btn:hover, .prev-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(91, 117, 83, 0.4);
}

.nav-btn {
    background: rgba(255, 255, 255, 0.9);
    border: 2px solid var(--dill-green);
    border-radius: 8px;
    padding: 0.75rem 1.25rem;
    font-weight: 600;
    color: var(--dill-green);
    cursor: pointer;
    transition: var(--eda-transition);
    margin: 0.25rem;
}

.nav-btn:hover {
    background: var(--butter-yellow);
    border-color: var(--butter-yellow);
    color: var(--dark-gray);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(255, 217, 91, 0.4);
}

.nav-btn.active {
    background: var(--butter-yellow);
    border-color: var(--butter-yellow);
    color: var(--dark-gray);
    box-shadow: 0 6px 20px rgba(255, 217, 91, 0.4);
    transform: translateY(-2px);
}

/* Code Block Styling - Beautiful Syntax Highlighting */
.code-block {
    margin: 1.5rem 0;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15);
    border: 1px solid rgba(91, 117, 83, 0.2);
}

.code-block pre {
    margin: 0;
    padding: 0;
    background: #2d3748 !important;
    border-radius: 12px;
    overflow-x: auto;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    line-height: 1.6;
}

.code-block code {
    display: block;
    padding: 1.5rem;
    background: transparent !important;
    color: #e2e8f0;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    line-height: 1.6;
    white-space: pre;
    overflow-x: auto;
}

/* Enhanced Prism.js Theme Colors */
.code-block .token.comment,
.code-block .token.prolog,
.code-block .token.doctype,
.code-block .token.cdata {
    color: #68d391;
    font-style: italic;
}

.code-block .token.punctuation {
    color: #e2e8f0;
}

.code-block .token.property,
.code-block .token.tag,
.code-block .token.boolean,
.code-block .token.number,
.code-block .token.constant,
.code-block .token.symbol,
.code-block .token.deleted {
    color: #f687b3;
}

.code-block .token.selector,
.code-block .token.attr-name,
.code-block .token.string,
.code-block .token.char,
.code-block .token.builtin,
.code-block .token.inserted {
    color: #68d391;
}

.code-block .token.operator,
.code-block .token.entity,
.code-block .token.url,
.code-block .language-css .token.string,
.code-block .style .token.string {
    color: #f6ad55;
}

.code-block .token.atrule,
.code-block .token.attr-value,
.code-block .token.keyword {
    color: #63b3ed;
    font-weight: 600;
}

.code-block .token.function,
.code-block .token.class-name {
    color: #fbb6ce;
    font-weight: 600;
}

.code-block .token.regex,
.code-block .token.important,
.code-block .token.variable {
    color: #f6ad55;
}

/* Code Block Header */
.code-block::before {
    content: "Python";
    display: block;
    background: linear-gradient(135deg, var(--dill-green), var(--aura-indigo));
    color: white;
    padding: 0.75rem 1.5rem;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Copy Button */
.code-block {
    position: relative;
}

.code-block .copy-btn {
    position: absolute;
    top: 0.75rem;
    right: 1rem;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    font-size: 0.8rem;
    cursor: pointer;
    transition: var(--eda-transition);
    font-family: var(--font-mono);
}

.code-block .copy-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-1px);
}

/* Chart and Canvas Containers */
.chart-container,
.viz-display,
.missing-data-viz,
.correlation-heatmap,
.distribution-viz,
.outlier-visualization,
.trend-item canvas {
    max-width: 60%;
    margin: 0 auto;
    display: block;
}

/* Preview charts in gallery should be smaller */
.viz-preview canvas {
    max-width: 100% !important;
    height: 150px !important;
    margin: 0 auto !important;
    display: block !important;
}

/* Specific preview chart sizing */
#difficulty-preview,
#acceptance-preview,
#likes-preview,
#companies-preview {
    max-width: 100% !important;
    height: 150px !important;
    margin: 0 auto !important;
}

/* Viz preview container */
.viz-preview {
    width: 100%;
    height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #f8f9fa;
    border-radius: 8px;
    margin-bottom: 2rem;
    padding: 1rem;
    box-sizing: border-box;
}

/* Viz card styling */
.viz-card {
    background: white;
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    padding: 1.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
    margin-bottom: 2rem;
    min-height: 300px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.viz-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    border-color: var(--eda-primary);
}

.viz-card h4 {
    color: var(--eda-primary);
    margin-bottom: 1rem;
    font-size: 1.1rem;
    font-weight: 600;
}

.viz-card p {
    color: var(--eda-dark);
    font-size: 0.9rem;
    line-height: 1.5;
}

/* Specific canvas sizing */
#outlierBoxPlot,
#correlationHeatmap,
#customVisualization,
#distributionChart,
#missingDataChart,
#trendChart1,
#trendChart2 {
    max-width: 60% !important;
    margin: 2rem auto !important;
    display: block !important;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    background: white;
    padding: 2rem !important;
    min-height: 300px;
    width: 100% !important;
    height: 400px !important;
}

/* Ensure canvas elements have proper dimensions */
canvas {
    width: 100% !important;
    height: auto !important;
    min-height: 200px !important;
}

/* Chart container styling */
.chart-container,
.viz-display,
.missing-data-viz,
.correlation-heatmap,
.distribution-viz,
.outlier-visualization {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    margin: 2rem auto;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    border: 1px solid #e0e0e0;
}

/* Chart titles and headers */
.chart-title,
.viz-title,
.section-title,
h3, h4 {
    margin-bottom: 1.5rem !important;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid #e2e8f0;
}

/* Visualization section spacing */
.viz-section,
.chart-section,
.content-section {
    margin-bottom: 3rem;
    padding: 1.5rem;
}

/* Method tabs styling */
.method-tabs {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    border-bottom: 2px solid #e2e8f0;
}

.method-tab {
    padding: 0.75rem 1.5rem;
    background: #f8f9fa;
    border: none;
    border-radius: 8px 8px 0 0;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
    color: #6b7280;
}

.method-tab.active {
    background: var(--eda-primary);
    color: white;
    transform: translateY(-2px);
}

.method-tab:hover:not(.active) {
    background: #e5e7eb;
    color: var(--eda-primary);
}

.method-content {
    display: none;
    padding: 2rem;
    background: white;
    border-radius: 0 8px 8px 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    margin-bottom: 2rem;
}

.method-content.active {
    display: block;
}

/* Tutorial Header */
.tutorial-header {
    background: var(--eda-gradient);
    color: white;
    padding: 4rem 2rem;
    text-align: center;
    border-radius: 0 0 2rem 2rem;
    margin-bottom: 3rem;
    box-shadow: var(--eda-shadow);
}

.tutorial-header h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.subtitle {
    font-size: 1.3rem;
    opacity: 0.9;
    margin-bottom: 2rem;
}

.meta-info {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.meta-item {
    background: rgba(255, 255, 255, 0.2);
    padding: 0.75rem 1.5rem;
    border-radius: 25px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

/* Download Section Styles */
.download-section {
    margin: 2rem 0;
    text-align: center;
}

.download-card {
    background: linear-gradient(135deg, #f8f9fa 0%, #e8f9f7 100%);
    border: 2px solid var(--eda-success);
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 8px 32px rgba(78, 205, 196, 0.15);
}

.download-card h4 {
    color: var(--eda-success);
    margin-bottom: 1rem;
    font-size: 1.4rem;
    font-weight: 700;
}

.download-card p {
    color: var(--eda-dark);
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    background: var(--eda-gradient);
    color: white;
    padding: 1rem 2rem;
    border-radius: 25px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.1rem;
    transition: all 0.3s ease;
    box-shadow: 0 4px 20px rgba(102, 126, 234, 0.3);
}

.download-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(102, 126, 234, 0.4);
    color: white;
    text-decoration: none;
}

.download-info {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-top: 1.5rem;
    flex-wrap: wrap;
}

.file-info {
    background: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    color: var(--eda-dark);
    border: 1px solid #e0e0e0;
}

/* Strategy Options */
.strategy-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin: 2.5rem 0;
    padding: 1rem;
}

.strategy-option {
    background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 8px 32px rgba(0,0,0,0.08);
    border: 2px solid #e8e9ea;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.strategy-option::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--eda-primary), var(--eda-secondary));
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.strategy-option:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 20px 40px rgba(102, 126, 234, 0.15);
    border-color: var(--eda-primary);
    background: linear-gradient(135deg, #ffffff 0%, #f0f4ff 100%);
}

.strategy-option:hover::before {
    transform: scaleX(1);
}

.strategy-option.selected {
    border-color: var(--eda-success);
    background: linear-gradient(135deg, #f0fffd 0%, #e8f9f7 100%);
    box-shadow: 0 12px 40px rgba(78, 205, 196, 0.2);
    transform: translateY(-4px);
}

.strategy-option.selected::before {
    background: linear-gradient(90deg, var(--eda-success), #26a69a);
    transform: scaleX(1);
}

.strategy-option h4 {
    color: var(--eda-dark);
    margin-bottom: 1rem;
    font-size: 1.3rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.strategy-option h4::before {
    content: '';
    width: 8px;
    height: 8px;
    background: var(--eda-primary);
    border-radius: 50%;
    display: inline-block;
}

.strategy-option.selected h4::before {
    background: var(--eda-success);
}

.strategy-option p {
    color: #555;
    font-size: 1rem;
    margin: 0;
    line-height: 1.6;
    font-weight: 500;
}

/* Solution Tabs */
.solution-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    justify-content: center;
}

.solution-tab {
    background: var(--eda-light);
    border: 2px solid transparent;
    color: var(--eda-dark);
    padding: 0.75rem 1.5rem;
    border-radius: 25px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--eda-transition);
    border: none;
    font-size: 0.9rem;
}

.solution-tab:hover {
    background: var(--eda-primary);
    color: white;
    transform: translateY(-2px);
}

.solution-tab.active {
    background: var(--eda-gradient);
    color: white;
    box-shadow: var(--eda-shadow);
}

/* Solution Content */
.solution-content {
    display: none;
    background: var(--eda-light);
    border-radius: var(--eda-border-radius);
    padding: 2rem;
    margin-bottom: 2rem;
    border: 1px solid #e0e0e0;
}

.solution-content.active {
    display: block;
}

.solution-content h4 {
    color: var(--eda-primary);
    margin-bottom: 1.5rem;
    font-size: 1.4rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.solution-content h4::before {
    content: '✅';
    font-size: 1.2rem;
}

/* Solution Explanation */
.solution-explanation {
    background: white;
    border-radius: 8px;
    padding: 1.5rem;
    margin-top: 1.5rem;
    border-left: 4px solid var(--eda-success);
}

.solution-explanation h5 {
    color: var(--eda-success);
    margin-bottom: 1rem;
    font-size: 1.1rem;
    font-weight: 600;
}

.solution-explanation ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.solution-explanation li {
    background: var(--eda-light);
    padding: 0.75rem 1rem;
    margin: 0.5rem 0;
    border-radius: 6px;
    border-left: 3px solid var(--eda-primary);
    font-weight: 500;
    color: var(--eda-dark);
}

.solution-explanation li strong {
    color: var(--eda-primary);
}

/* Responsive Design */
@media (max-width: 768px) {
    .strategy-options {
        grid-template-columns: 1fr;
        gap: 1.5rem;
        padding: 0.5rem;
    }
    
    .solution-tabs {
        flex-direction: column;
        align-items: center;
    }
    
    .solution-tab {
        width: 100%;
        max-width: 300px;
        text-align: center;
    }
    
    .download-info {
        flex-direction: column;
        gap: 1rem;
    }
    
    .file-info {
        width: 100%;
        text-align: center;
    }
}

/* Course Navigation */
.course-nav {
    background: white;
    border-radius: var(--eda-border-radius);
    padding: 2rem;
    margin-bottom: 3rem;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    border: 1px solid #e0e0e0;
}

.course-nav h3 {
    color: var(--eda-primary);
    margin-bottom: 1.5rem;
    text-align: center;
    font-size: 1.5rem;
}

.nav-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.nav-btn {
    background: var(--eda-light);
    border: 2px solid transparent;
    color: var(--eda-dark);
    padding: 1rem 1.5rem;
    border-radius: 10px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--eda-transition);
    text-align: center;
    font-size: 0.95rem;
}

.nav-btn:hover {
    background: var(--eda-primary);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--eda-shadow);
}

.nav-btn.active {
    background: var(--eda-gradient);
    color: white;
    box-shadow: var(--eda-shadow);
}

/* Content Sections */
.content-section {
    display: none;
    background: white;
    border-radius: var(--eda-border-radius);
    padding: 3rem;
    margin-bottom: 3rem;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    border: 1px solid #e0e0e0;
}

.content-section.active {
    display: block;
}

.content-section h2 {
    color: var(--eda-primary);
    margin-bottom: 2rem;
    font-size: 2.5rem;
    text-align: center;
    font-weight: 700;
}

.section-intro {
    background: var(--eda-light);
    border-radius: var(--eda-border-radius);
    padding: 2rem;
    margin-bottom: 2rem;
    border-left: 4px solid var(--eda-primary);
}

.section-intro p {
    color: var(--eda-dark);
    font-size: 1.1rem;
    line-height: 1.6;
    margin: 0;
}

/* Dataset Overview */
.dataset-overview {
    background: var(--eda-light);
    border-radius: var(--eda-border-radius);
    padding: 2rem;
    margin-bottom: 2rem;
}

.dataset-overview h3 {
    color: var(--eda-primary);
    margin-bottom: 1.5rem;
    font-size: 1.4rem;
}

.dataset-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: white;
    padding: 1.5rem;
    border-radius: 10px;
    text-align: center;
    border: 1px solid #e0e0e0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--eda-primary);
    margin-bottom: 0.5rem;
}

.stat-label {
    color: var(--eda-dark);
    font-weight: 600;
}

.dataset-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
}

.action-btn {
    background: var(--eda-primary);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--eda-transition);
}

.action-btn:hover {
    background: var(--eda-secondary);
    transform: translateY(-2px);
}

/* Strategy button specific styling */
.strategy-btn {
    background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 8px 32px rgba(0,0,0,0.08);
    border: 2px solid #e8e9ea;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    text-align: left;
    width: 100%;
    font-family: inherit;
}

.strategy-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--eda-primary), var(--eda-secondary));
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.strategy-btn:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 20px 40px rgba(102, 126, 234, 0.15);
    border-color: var(--eda-primary);
    background: linear-gradient(135deg, #ffffff 0%, #f0f4ff 100%);
}

.strategy-btn:hover::before {
    transform: scaleX(1);
}

.strategy-btn.active {
    border-color: var(--eda-success);
    background: linear-gradient(135deg, #f0fffd 0%, #e8f9f7 100%);
    box-shadow: 0 12px 40px rgba(78, 205, 196, 0.2);
    transform: translateY(-4px);
}

.strategy-btn.active::before {
    background: linear-gradient(90deg, var(--eda-success), #26a69a);
    transform: scaleX(1);
}

.strategy-btn h4 {
    color: var(--eda-dark);
    margin-bottom: 1rem;
    font-size: 1.3rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.strategy-btn h4::before {
    content: '';
    width: 8px;
    height: 8px;
    background: var(--eda-primary);
    border-radius: 50%;
    display: inline-block;
}

.strategy-btn.active h4::before {
    background: var(--eda-success);
}

.strategy-btn .strategy-desc {
    color: #555;
    font-size: 1rem;
    margin: 0;
    line-height: 1.6;
    font-weight: 500;
    display: block;
    margin-top: 0.5rem;
}

/* Strategy result styling */
.strategy-result {
    background: linear-gradient(135deg, #f8f9fa 0%, #e8f9f7 100%);
    border-radius: 16px;
    padding: 2rem;
    margin-top: 2rem;
    border: 2px solid var(--eda-success);
    box-shadow: 0 8px 32px rgba(78, 205, 196, 0.15);
}

.strategy-result h4 {
    color: var(--eda-success);
    margin-bottom: 1rem;
    font-size: 1.4rem;
    font-weight: 700;
}

.strategy-result ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.strategy-result li {
    background: white;
    padding: 0.75rem 1rem;
    margin: 0.5rem 0;
    border-radius: 8px;
    border-left: 4px solid var(--eda-success);
    font-weight: 500;
    color: var(--eda-dark);
}

/* Section Navigation */
.section-navigation {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 3rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.prev-btn, .next-btn {
    background: var(--eda-primary);
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 25px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--eda-transition);
    text-decoration: none;
    display: inline-block;
}

.prev-btn:hover, .next-btn:hover {
    background: var(--eda-secondary);
    transform: translateY(-2px);
    color: white;
    text-decoration: none;
}

/* Completion Badge */
.completion-badge {
    text-align: center;
    margin-top: 3rem;
    padding: 2rem;
    background: linear-gradient(135deg, var(--eda-success), #26a69a);
    border-radius: var(--eda-border-radius);
    color: white;
}

.badge-text {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 1rem;
    display: block;
}

.completion-badge p {
    font-size: 1.2rem;
    margin: 0;
    opacity: 0.9;
}

/* Code Blocks */
.code-block {
    background: #2d3748;
    border-radius: 10px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    overflow-x: auto;
}

.code-block pre {
    margin: 0;
    color: #e2e8f0;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 0.9rem;
    line-height: 1.5;
}

.code-block code {
    color: inherit;
}

/* Visualization Controls */
.viz-controls {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: var(--eda-light);
    border-radius: var(--eda-border-radius);
    border: 1px solid #e0e0e0;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.control-group label {
    font-weight: 600;
    color: var(--eda-dark);
    font-size: 0.9rem;
}

.control-group select {
    padding: 0.75rem;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    background: white;
    font-size: 0.9rem;
    transition: var(--eda-transition);
}

.control-group select:focus {
    outline: none;
    border-color: var(--eda-primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.viz-settings-btn {
    background: var(--eda-gradient);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--eda-transition);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
}

.viz-settings-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--eda-shadow);
}

.viz-settings-panel {
    background: white;
    border: 2px solid var(--eda-primary);
    border-radius: var(--eda-border-radius);
    padding: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--eda-shadow);
}

.viz-settings-panel h4 {
    color: var(--eda-primary);
    margin-bottom: 1rem;
    font-size: 1.2rem;
    font-weight: 700;
}

.settings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.setting-item {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.setting-item label {
    font-weight: 600;
    color: var(--eda-dark);
    font-size: 0.9rem;
}

.setting-item select,
.setting-item input[type="checkbox"] {
    padding: 0.5rem;
    border: 2px solid #e0e0e0;
    border-radius: 6px;
    background: white;
    transition: var(--eda-transition);
}

.setting-item select:focus {
    outline: none;
    border-color: var(--eda-primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.setting-item input[type="checkbox"] {
    width: 20px;
    height: 20px;
    accent-color: var(--eda-primary);
}

/* Improved Button Styling */
button, .btn {
    background: var(--eda-gradient);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--eda-transition);
    font-size: 0.9rem;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    justify-content: center;
}

button:hover, .btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--eda-shadow);
    color: white;
    text-decoration: none;
}

button:active, .btn:active {
    transform: translateY(0);
}

/* Demo Controls */
.demo-controls {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 1.5rem;
    justify-content: center;
}

.demo-controls button {
    background: var(--eda-primary);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 25px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--eda-transition);
    font-size: 0.9rem;
}

.demo-controls button:hover {
    background: var(--eda-secondary);
    transform: translateY(-2px);
    box-shadow: var(--eda-shadow);
}

/* Method Tabs */
.method-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    justify-content: center;
}

.method-tab {
    background: var(--eda-light);
    border: 2px solid transparent;
    color: var(--eda-dark);
    padding: 0.75rem 1.5rem;
    border-radius: 25px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--eda-transition);
    font-size: 0.9rem;
}

.method-tab:hover {
    background: var(--eda-primary);
    color: white;
    transform: translateY(-2px);
}

.method-tab.active {
    background: var(--eda-gradient);
    color: white;
    box-shadow: var(--eda-shadow);
}

/* Converter Controls */
.converter-controls {
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: var(--eda-light);
    border-radius: 8px;
}

.converter-controls label {
    font-weight: 600;
    color: var(--eda-dark);
}

.converter-controls input[type="text"] {
    padding: 0.75rem;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    background: white;
    font-size: 0.9rem;
    transition: var(--eda-transition);
    min-width: 150px;
}

.converter-controls input[type="text"]:focus {
    outline: none;
    border-color: var(--eda-primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.converter-controls button {
    background: var(--eda-primary);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--eda-transition);
    font-size: 0.9rem;
}

.converter-controls button:hover {
    background: var(--eda-secondary);
    transform: translateY(-2px);
    box-shadow: var(--eda-shadow);
}

/* Column Selector */
.column-selector {
    display: flex;
    gap: 1rem;
    align-items: center;
    margin-bottom: 2rem;
    padding: 1rem;
    background: var(--eda-light);
    border-radius: 8px;
    flex-wrap: wrap;
}

.column-selector label {
    font-weight: 600;
    color: var(--eda-dark);
}

.column-selector select {
    padding: 0.75rem;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    background: white;
    font-size: 0.9rem;
    transition: var(--eda-transition);
    min-width: 200px;
}

.column-selector select:focus {
    outline: none;
    border-color: var(--eda-primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

/* Percentile Controls */
.percentile-controls {
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
    margin-bottom: 2rem;
    padding: 1rem;
    background: var(--eda-light);
    border-radius: 8px;
}

.percentile-controls label {
    font-weight: 600;
    color: var(--eda-dark);
}

.percentile-checkboxes {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.percentile-checkboxes label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
    color: var(--eda-dark);
}

.percentile-checkboxes input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: var(--eda-primary);
}

.percentile-controls button {
    background: var(--eda-primary);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--eda-transition);
    font-size: 0.9rem;
}

.percentile-controls button:hover {
    background: var(--eda-secondary);
    transform: translateY(-2px);
    box-shadow: var(--eda-shadow);
}

/* Mobile responsive improvements */
@media (max-width: 768px) {
    .tutorial-header {
        padding: 3rem 1rem;
    }
    
    .tutorial-header h1 {
        font-size: 2.5rem;
    }
    
    .subtitle {
        font-size: 1.1rem;
    }
    
    .meta-info {
        flex-direction: column;
        gap: 1rem;
    }
    
    .content-section {
        padding: 2rem 1rem;
    }
    
    .course-nav {
        padding: 1rem;
    }
    
    .nav-btn {
        padding: 0.75rem 1rem;
        font-size: 0.8rem;
    }
    
    .section-navigation {
        flex-direction: column;
        gap: 1rem;
    }
    
    .strategy-btn, .strategy-option {
        padding: 1.5rem;
    }
    
    .strategy-btn h4, .strategy-option h4 {
        font-size: 1.2rem;
    }
    
    .strategy-btn .strategy-desc, .strategy-option p {
        font-size: 0.95rem;
    }
    
    .download-btn {
        padding: 0.875rem 1.5rem;
        font-size: 1rem;
    }
    
    .viz-controls {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .settings-grid {
        grid-template-columns: 1fr;
    }
    
    .demo-controls {
        flex-direction: column;
        align-items: center;
    }
    
    .converter-controls {
        flex-direction: column;
        align-items: stretch;
    }
    
    .column-selector {
        flex-direction: column;
        align-items: stretch;
    }
    
    .percentile-controls {
        flex-direction: column;
        align-items: stretch;
    }
    
    .percentile-checkboxes {
        justify-content: center;
    }
    
    /* Header responsive styles */
    .azbn-header .azbn-container {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }
    
    .azbn-links {
        gap: 1rem;
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .azbn-links a {
        padding: 0.5rem;
        font-size: 0.9rem;
    }
    
    /* Mobile canvas sizing */
    .chart-container,
    .viz-display,
    .missing-data-viz,
    .correlation-heatmap,
    .distribution-viz,
    .outlier-visualization,
    .trend-item canvas {
        max-width: 95%;
    }
    
    #outlierBoxPlot,
    #correlationHeatmap,
    #customVisualization,
    #distributionChart,
    #missingDataChart,
    #trendChart1,
    #trendChart2 {
        max-width: 95% !important;
    }
}