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

:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --accent-color: #ec4899;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --border-color: #334155;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    padding: 2rem;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
}

.category-nav {
    display: flex;
    justify-content: center;
    gap: 1rem;
    padding: 1.5rem;
    background: var(--card-bg);
    border-bottom: 2px solid var(--border-color);
    flex-wrap: wrap;
}

.nav-btn {
    padding: 0.75rem 1.5rem;
    background: var(--bg-color);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.nav-btn:hover {
    background: var(--primary-color);
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.nav-btn.active {
    background: var(--primary-color);
    border-color: var(--primary-color);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
}

.content-container {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 1rem;
}

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

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

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

.content-section h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.intro {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.8;
}

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

.ml-card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 12px;
    border: 2px solid var(--border-color);
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
}

.ml-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: 0 8px 24px rgba(99, 102, 241, 0.3);
}

.card-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.ml-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

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

.visual-demo {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 12px;
    margin: 2rem 0;
    border: 2px solid var(--border-color);
}

.visual-demo h3 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    text-align: center;
}

.animation-box {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
    padding: 2rem;
}

.process-step {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: 1.5rem;
    background: var(--bg-color);
    border-radius: 12px;
    border: 2px solid var(--primary-color);
    min-width: 150px;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% {
        box-shadow: 0 0 0 0 rgba(99, 102, 241, 0.7);
    }
    50% {
        box-shadow: 0 0 20px 10px rgba(99, 102, 241, 0);
    }
}

.step-number {
    font-size: 2rem;
    font-weight: bold;
    color: var(--primary-color);
}

.step-text {
    font-size: 1rem;
    color: var(--text-secondary);
}

.arrow {
    font-size: 2rem;
    color: var(--primary-color);
}

.arrow-down {
    font-size: 2rem;
    color: var(--primary-color);
    text-align: center;
    margin: 1rem 0;
}

.subcategory {
    margin: 3rem 0;
}

.subcategory h3 {
    font-size: 2rem;
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.subcategory > p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.example-box {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 12px;
    border: 2px solid var(--border-color);
    margin-top: 1rem;
}

.example-box h4 {
    color: var(--accent-color);
    font-size: 1.3rem;
    margin-bottom: 1.5rem;
}

.classification-demo {
    display: flex;
    gap: 2rem;
    justify-content: center;
    flex-wrap: wrap;
}

.email-example {
    padding: 1.5rem;
    border-radius: 8px;
    max-width: 300px;
    text-align: center;
}

.email-example.spam {
    background: rgba(239, 68, 68, 0.1);
    border: 2px solid var(--danger-color);
}

.email-example.not-spam {
    background: rgba(16, 185, 129, 0.1);
    border: 2px solid var(--success-color);
}

.email-example .label {
    display: inline-block;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-weight: bold;
    margin-bottom: 1rem;
}

.spam .label {
    background: var(--danger-color);
}

.not-spam .label {
    background: var(--success-color);
}

.regression-demo {
    padding: 1rem;
}

.chart-container {
    height: 200px;
    background: var(--bg-color);
    border-radius: 8px;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

#regressionChart {
    width: 100%;
    height: 100%;
}

.regression-inputs {
    text-align: center;
}

.regression-inputs label {
    display: block;
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

#sizeSlider {
    width: 100%;
    max-width: 400px;
    margin: 1rem auto;
    display: block;
}

.prediction {
    margin-top: 1.5rem;
    padding: 1rem;
    background: var(--primary-color);
    border-radius: 8px;
    font-size: 1.5rem;
    font-weight: bold;
}

.clustering-demo {
    padding: 1rem;
}

.cluster-container {
    display: flex;
    gap: 2rem;
    justify-content: space-around;
    flex-wrap: wrap;
}

.cluster {
    padding: 1.5rem;
    border-radius: 12px;
    min-width: 150px;
    text-align: center;
    position: relative;
    animation: float 3s ease-in-out infinite;
}

.cluster1 {
    background: rgba(239, 68, 68, 0.2);
    border: 2px solid var(--danger-color);
}

.cluster2 {
    background: rgba(99, 102, 241, 0.2);
    border: 2px solid var(--primary-color);
}

.cluster3 {
    background: rgba(16, 185, 129, 0.2);
    border: 2px solid var(--success-color);
}

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

.cluster-label {
    font-weight: bold;
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.data-point {
    width: 12px;
    height: 12px;
    background: currentColor;
    border-radius: 50%;
    margin: 0.5rem auto;
    animation: pointPulse 1.5s infinite;
}

@keyframes pointPulse {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.6;
        transform: scale(1.2);
    }
}

.dimension-demo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.dimension-box {
    background: var(--bg-color);
    padding: 2rem;
    border-radius: 8px;
    border: 2px solid var(--primary-color);
    text-align: center;
    width: 100%;
    max-width: 400px;
}

.dimension-box.reduced {
    border-color: var(--success-color);
}

.dim-label {
    font-weight: bold;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.features {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: center;
}

.features span {
    padding: 0.5rem 1rem;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.9rem;
}

.association-demo {
    padding: 2rem;
    text-align: center;
}

.basket {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.item {
    padding: 1rem 2rem;
    background: var(--bg-color);
    border: 2px solid var(--primary-color);
    border-radius: 8px;
    font-size: 1.2rem;
}

.association-arrow {
    font-size: 2rem;
    color: var(--accent-color);
}

.rule {
    font-style: italic;
    color: var(--text-secondary);
    margin-top: 1rem;
}

.rl-demo {
    padding: 1rem;
}

.rl-game {
    text-align: center;
}

.game-grid {
    display: grid;
    grid-template-columns: repeat(3, 100px);
    gap: 10px;
    justify-content: center;
    margin: 2rem auto;
}

.grid-cell {
    width: 100px;
    height: 100px;
    background: var(--bg-color);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    transition: all 0.3s ease;
}

.grid-cell.start {
    background: rgba(99, 102, 241, 0.2);
    border-color: var(--primary-color);
}

.grid-cell.obstacle {
    background: rgba(239, 68, 68, 0.2);
    border-color: var(--danger-color);
}

.grid-cell.reward {
    background: rgba(245, 158, 11, 0.2);
    border-color: var(--warning-color);
    animation: glow 1.5s infinite;
}

@keyframes glow {
    0%, 100% {
        box-shadow: 0 0 5px var(--warning-color);
    }
    50% {
        box-shadow: 0 0 20px var(--warning-color);
    }
}

.rl-controls {
    margin: 2rem auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
}

.rl-controls div {
    display: flex;
    gap: 0.5rem;
}

.rl-controls button {
    width: 50px;
    height: 50px;
    font-size: 1.5rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.rl-controls button:hover {
    background: var(--secondary-color);
    transform: scale(1.1);
}

.rl-stats {
    margin-top: 2rem;
    padding: 1rem;
    background: var(--bg-color);
    border-radius: 8px;
}

.rl-stats p {
    font-size: 1.2rem;
    margin: 0.5rem 0;
}

.rl-stats button {
    margin-top: 1rem;
    padding: 0.75rem 2rem;
    background: var(--danger-color);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.rl-stats button:hover {
    background: #dc2626;
    transform: scale(1.05);
}

.rl-concepts {
    margin-top: 2rem;
}

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

.concept {
    padding: 1rem;
    background: var(--bg-color);
    border-radius: 8px;
    border-left: 4px solid var(--primary-color);
}

.algorithm-list {
    margin-top: 2rem;
    padding: 1.5rem;
    background: var(--bg-color);
    border-radius: 8px;
    border-left: 4px solid var(--secondary-color);
}

.algorithm-list strong {
    color: var(--secondary-color);
    font-size: 1.1rem;
}

.algorithm-list ul {
    margin-top: 1rem;
    margin-left: 1.5rem;
}

.algorithm-list li {
    margin: 0.5rem 0;
    color: var(--text-secondary);
}

.use-cases {
    margin-top: 2rem;
    padding: 1.5rem;
    background: var(--bg-color);
    border-radius: 8px;
    border-left: 4px solid var(--accent-color);
}

.use-cases h4 {
    color: var(--accent-color);
    margin-bottom: 1rem;
}

.use-cases ul {
    margin-left: 1.5rem;
}

.use-cases li {
    margin: 0.5rem 0;
    color: var(--text-secondary);
}

.semi-supervised-demo {
    padding: 2rem;
}

.data-mix {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.labeled-section, .unlabeled-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem;
    background: var(--bg-color);
    border-radius: 8px;
}

.section-title {
    font-weight: bold;
    color: var(--primary-color);
}

.point {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: bold;
}

.point.labeled {
    background: rgba(16, 185, 129, 0.3);
    border: 2px solid var(--success-color);
    color: var(--success-color);
}

.point.unlabeled {
    background: rgba(203, 213, 225, 0.2);
    border: 2px solid var(--text-secondary);
    color: var(--text-secondary);
}

.plus {
    font-size: 2rem;
    color: var(--primary-color);
}

.self-supervised-demo {
    padding: 2rem;
}

.ssl-example {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.sentence {
    font-size: 1.5rem;
    padding: 1.5rem;
    background: var(--bg-color);
    border-radius: 8px;
    text-align: center;
}

.prediction-arrow {
    font-size: 1.5rem;
    color: var(--primary-color);
    font-weight: bold;
}

.prediction-word {
    font-size: 2rem;
    padding: 1rem 2rem;
    background: var(--primary-color);
    border-radius: 8px;
    font-weight: bold;
}

.transfer-demo {
    padding: 2rem;
}

.transfer-flow {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.model-box {
    padding: 2rem;
    background: var(--bg-color);
    border: 2px solid var(--primary-color);
    border-radius: 12px;
    text-align: center;
    min-width: 200px;
}

.model-box.adapted {
    border-color: var(--success-color);
}

.model-box strong {
    color: var(--primary-color);
    font-size: 1.2rem;
    display: block;
    margin-bottom: 1rem;
}

.model-box.adapted strong {
    color: var(--success-color);
}

.arrow-right {
    font-size: 2rem;
    color: var(--primary-color);
}

.online-learning-demo {
    padding: 2rem;
}

.data-stream {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.stream-item {
    padding: 1rem 2rem;
    background: var(--bg-color);
    border: 2px solid var(--primary-color);
    border-radius: 8px;
    font-size: 1.2rem;
    animation: slideIn 1s ease;
}

@keyframes slideIn {
    from {
        transform: translateX(-100px);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

.model-update {
    padding: 1.5rem;
    background: var(--success-color);
    border-radius: 8px;
    font-weight: bold;
    font-size: 1.2rem;
    animation: pulse 2s infinite;
}

.ensemble-demo {
    padding: 2rem;
}

.ensemble-models {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.single-model {
    padding: 1rem 2rem;
    background: var(--bg-color);
    border: 2px solid var(--primary-color);
    border-radius: 8px;
    font-size: 1.2rem;
    min-width: 200px;
    text-align: center;
}

.voting {
    font-size: 1.5rem;
    color: var(--primary-color);
    font-weight: bold;
    margin: 1rem 0;
}

.final-prediction {
    padding: 1.5rem 3rem;
    background: var(--success-color);
    border-radius: 8px;
    font-size: 1.5rem;
    font-weight: bold;
}

/* Algorithm Cards */
.algorithms-detailed {
    margin-top: 2rem;
}

.algorithms-detailed h4 {
    color: var(--primary-color);
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    border-bottom: 2px solid var(--primary-color);
    padding-bottom: 0.5rem;
}

.algorithm-card {
    background: var(--bg-color);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    transition: all 0.3s ease;
}

.algorithm-card:hover {
    border-color: var(--primary-color);
    box-shadow: 0 4px 16px rgba(99, 102, 241, 0.2);
    transform: translateX(5px);
}

.algo-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.algo-header h5 {
    font-size: 1.3rem;
    color: var(--text-primary);
    margin: 0;
}

.complexity {
    padding: 0.4rem 0.8rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    background: var(--secondary-color);
    color: white;
}

.algo-desc {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.6;
}

.algo-details {
    display: grid;
    gap: 0.75rem;
    margin-top: 1rem;
}

.detail-item {
    padding: 0.75rem;
    background: var(--card-bg);
    border-left: 3px solid var(--primary-color);
    border-radius: 4px;
}

.detail-item strong {
    color: var(--primary-color);
    margin-right: 0.5rem;
}

/* Comparison Section */
.comparison-tool {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 12px;
    margin: 2rem 0;
    border: 2px solid var(--border-color);
}

.comparison-tool h3 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    text-align: center;
}

.selector-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.selector-card {
    background: var(--bg-color);
    padding: 1.5rem;
    border-radius: 8px;
    border: 2px solid var(--border-color);
}

.selector-card h4 {
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.selector-dropdown {
    width: 100%;
    padding: 0.75rem;
    background: var(--card-bg);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
    border-radius: 6px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.selector-dropdown:hover,
.selector-dropdown:focus {
    border-color: var(--primary-color);
    outline: none;
}

.selector-dropdown option {
    background: var(--card-bg);
    color: var(--text-primary);
}

.recommend-btn {
    display: block;
    margin: 2rem auto;
    padding: 1rem 3rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.recommend-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4);
}

.recommendation-result {
    margin-top: 2rem;
    padding: 2rem;
    background: var(--bg-color);
    border-radius: 8px;
    border: 2px solid var(--primary-color);
}

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

#recommendationContent {
    color: var(--text-secondary);
}

.recommended-algo {
    background: var(--card-bg);
    padding: 1rem;
    margin: 1rem 0;
    border-left: 4px solid var(--success-color);
    border-radius: 4px;
}

.recommended-algo h5 {
    color: var(--success-color);
    margin-bottom: 0.5rem;
}

/* Comparison Tables */
.comparison-tables {
    margin-top: 3rem;
}

.comparison-tables h3 {
    color: var(--primary-color);
    margin-bottom: 2rem;
    text-align: center;
}

.comparison-table {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 2rem;
    border: 2px solid var(--border-color);
    overflow-x: auto;
}

.comparison-table h4 {
    color: var(--secondary-color);
    margin-bottom: 1.5rem;
}

.comparison-table table {
    width: 100%;
    border-collapse: collapse;
}

.comparison-table th {
    background: var(--bg-color);
    color: var(--primary-color);
    padding: 1rem;
    text-align: left;
    border-bottom: 2px solid var(--primary-color);
    font-weight: 600;
}

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

.comparison-table tr:hover {
    background: var(--bg-color);
}

.comparison-table tbody tr {
    transition: all 0.3s ease;
}

footer {
    text-align: center;
    padding: 2rem;
    background: var(--card-bg);
    margin-top: 4rem;
    border-top: 2px solid var(--border-color);
}

@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }

    .category-nav {
        gap: 0.5rem;
    }

    .nav-btn {
        padding: 0.5rem 1rem;
        font-size: 0.9rem;
    }

    .content-section h2 {
        font-size: 2rem;
    }

    .card-grid {
        grid-template-columns: 1fr;
    }

    .game-grid {
        grid-template-columns: repeat(3, 80px);
    }

    .grid-cell {
        width: 80px;
        height: 80px;
        font-size: 1.5rem;
    }

    .animation-box {
        flex-direction: column;
    }

    .arrow {
        transform: rotate(90deg);
    }
}