/* CSS Variables for Theming */
:root {
    /* Light Theme Colors */
    --bg-primary-light: #ffffff;
    --bg-secondary-light: #f8f9fa;
    --bg-card-light: #ffffff;
    --text-primary-light: #1f2937;
    --text-secondary-light: #6b7280;
    --border-light: #e5e7eb;
    --shadow-light: 0 4px 6px -1px rgb(0 0 0 / 0.1);

    /* Dark Theme Colors */
    --bg-primary-dark: #0f172a;
    --bg-secondary-dark: #1e293b;
    --bg-card-dark: #334155;
    --text-primary-dark: #f8fafc;
    --text-secondary-dark: #cbd5e1;
    --border-dark: #475569;
    --shadow-dark: 0 4px 6px -1px rgb(0 0 0 / 0.3);

    /* Accent Colors (same for both themes) */
    --accent-primary: #667eea;
    --accent-secondary: #764ba2;
    --accent-success: #22c55e;
    --accent-warning: #f59e0b;
    --accent-error: #ef4444;
    --accent-info: #0ea5e9;

    /* Default to Dark Theme */
    --bg-primary: var(--bg-primary-dark);
    --bg-secondary: var(--bg-secondary-dark);
    --bg-card: var(--bg-card-dark);
    --text-primary: var(--text-primary-dark);
    --text-secondary: var(--text-secondary-dark);
    --border-color: var(--border-dark);
    --shadow: var(--shadow-dark);

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-dark: linear-gradient(135deg, #1e293b 0%, #334155 100%);
    --gradient-card: linear-gradient(135deg, var(--bg-card) 0%, var(--bg-secondary) 100%);
}

/* Light Theme Override */
body.light-theme {
    --bg-primary: var(--bg-primary-light);
    --bg-secondary: var(--bg-secondary-light);
    --bg-card: var(--bg-card-light);
    --text-primary: var(--text-primary-light);
    --text-secondary: var(--text-secondary-light);
    --border-color: var(--border-light);
    --shadow: var(--shadow-light);
    --gradient-card: linear-gradient(135deg, var(--bg-card-light) 0%, var(--bg-secondary-light) 100%);
}

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

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--gradient-hero);
    min-height: 100vh;
    transition: all 0.3s ease;
}

/* Dark theme body background */
body:not(.light-theme) {
    background: var(--gradient-dark-bg);
}

/* Light theme body background */
body.light-theme {
    background: var(--gradient-primary);
}

.presentation-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
    background: var(--bg-primary);
    border-radius: 15px;
    box-shadow: var(--shadow);
    min-height: calc(100vh - 40px);
    display: flex;
    flex-direction: column;
    border: 1px solid var(--border-color);
}

/* Header Styles */
.header {
    text-align: center;
    padding: 30px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 10px;
    margin-bottom: 30px;
    color: white;
}

.header h1 {
    font-size: 3.5rem;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.header p {
    font-size: 1.3rem;
    opacity: 0.9;
}

/* Navigation Styles */
.slide-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
    border-bottom: 2px solid var(--border-color);
    margin-bottom: 30px;
}

.slide-nav button {
    background: #667eea;
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 25px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: bold;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
}

.slide-nav button:hover {
    background: #5a67d8;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

.slide-nav button:disabled {
    background: #ccc;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

#slideCounter {
    font-size: 1.1rem;
    font-weight: bold;
    color: var(--text-secondary);
    background: var(--bg-secondary);
    padding: 8px 16px;
    border-radius: 20px;
}

/* Slide Container */
.slide-container {
    flex: 1;
    position: relative;
    overflow: hidden;
}

.slide {
    display: none !important;
    animation: slideIn 0.5s ease-in-out;
    width: 100%;
    min-height: 400px;
    padding: 20px;
}

.slide.active {
    display: block !important;
    background: red !important;
    color: white !important;
    opacity: 1 !important;
    visibility: visible !important;
    border: 5px solid yellow !important;
    min-height: 500px !important;
}

.slide.active * {
    color: white !important;
    opacity: 1 !important;
    visibility: visible !important;
}

.slide.active h2 {
    color: white !important;
    font-size: 2.5rem !important;
    margin-bottom: 2rem !important;
    display: block !important;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(30px);
    }

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.slide h2 {
    font-size: 2.8rem;
    margin-bottom: 30px;
    color: var(--text-primary);
    text-align: center;
    position: relative;
}

.slide h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 120px;
    height: 4px;
    background: linear-gradient(90deg, #667eea, #764ba2);
    border-radius: 2px;
}

/* Introduction Slide Styles */
.intro-content {
    display: grid;
    gap: 30px;
    margin-top: 40px;
}

.session-info {
    background: var(--bg-secondary);
    padding: 30px;
    border-radius: 15px;
    border-left: 5px solid var(--accent-primary);
    margin-bottom: 30px;
    border: 1px solid var(--border-color);
}

.info-card h3 {
    color: var(--text-primary);
    font-size: 1.8rem;
    margin-bottom: 15px;
}

.info-card ul {
    list-style: none;
}

.info-card li {
    padding: 8px 0;
    padding-left: 25px;
    position: relative;
    font-size: 1.1rem;
}

.info-card li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--accent-primary);
    font-weight: bold;
}

.topics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
}

.topic-card {
    background: var(--bg-card);
    padding: 30px;
    border-radius: 15px;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease;
    border-top: 4px solid var(--accent-primary);
    border: 1px solid var(--border-color);
}

.topic-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
}

.csr-card {
    border-top-color: #3b82f6;
}

.ssr-card {
    border-top-color: #10b981;
}

.ssg-card {
    border-top-color: #f59e0b;
}

.api-card {
    border-top-color: var(--accent-secondary);
}

.topic-icon {
    font-size: 3rem;
    margin-bottom: 15px;
    text-align: center;
}

.topic-card h3 {
    color: var(--text-primary);
    margin-bottom: 15px;
    font-size: 1.4rem;
    text-align: center;
}

.topic-card p {
    color: var(--text-secondary);
    margin-bottom: 20px;
    text-align: center;
    line-height: 1.6;
}

.topic-stats {
    display: flex;
    justify-content: center;
    gap: 10px;
    flex-wrap: wrap;
}

.stat {
    background: var(--bg-accent);
    color: var(--text-accent);
    padding: 4px 8px;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 500;
    border: 1px solid var(--border-color);
}

/* Evolution Timeline */
.evolution-content {
    margin-top: 30px;
}

.timeline {
    display: flex;
    flex-direction: column;
    gap: 30px;
    margin-bottom: 40px;
}

.timeline-item {
    display: flex;
    align-items: center;
    gap: 30px;
    background: var(--bg-card);
    padding: 25px;
    border-radius: 15px;
    box-shadow: var(--shadow);
    border-left: 5px solid var(--accent-primary);
    border: 1px solid var(--border-color);
}

.timeline-year {
    background: var(--gradient-primary);
    color: white;
    padding: 10px 20px;
    border-radius: 25px;
    font-weight: bold;
    font-size: 1.1rem;
    min-width: 80px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.timeline-content {
    flex: 1;
}

.timeline-content h3 {
    color: var(--text-primary);
    margin-bottom: 10px;
    font-size: 1.3rem;
}

.timeline-content p {
    color: var(--text-secondary);
    margin-bottom: 10px;
}

.tech-stack {
    background: var(--bg-accent);
    color: var(--text-accent);
    padding: 5px 15px;
    border-radius: 15px;
    font-size: 0.9rem;
    font-weight: 500;
    display: inline-block;
    border: 1px solid var(--border-color);
}

.evolution-metrics {
    background: var(--bg-secondary);
    padding: 30px;
    border-radius: 15px;
    border-left: 5px solid var(--accent-success);
    border: 1px solid var(--border-color);
}

.evolution-metrics h3 {
    color: var(--text-primary);
    margin-bottom: 20px;
    text-align: center;
}

.metrics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.metric-item {
    background: var(--bg-card);
    padding: 20px;
    border-radius: 10px;
    text-align: center;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.metric-value {
    font-size: 2rem;
    font-weight: bold;
    color: var(--accent-success);
    margin-bottom: 5px;
    text-shadow: 0 0 10px rgba(16, 185, 129, 0.3);
}

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

/* Comparison Table */
.comparison-content {
    margin-top: 30px;
}

.comparison-table {
    background: var(--bg-card);
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow);
    margin-bottom: 40px;
    border: 1px solid var(--border-color);
}

.table-header {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    background: var(--bg-secondary);
}

.table-row {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    border-bottom: 1px solid #e5e7eb;
}

.table-row:last-child {
    border-bottom: none;
}

.header-cell,
.cell {
    padding: 15px 20px;
    text-align: center;
    font-weight: 500;
}

.header-cell {
    background: var(--text-primary);
    color: var(--bg-primary);
    font-weight: 600;
}

.csr-bg {
    background: rgba(59, 130, 246, 0.1);
    color: #1e40af;
}

.ssr-bg {
    background: rgba(16, 185, 129, 0.1);
    color: #065f46;
}

.ssg-bg {
    background: rgba(245, 158, 11, 0.1);
    color: #92400e;
}

.aspect {
    background: var(--bg-secondary) !important;
    color: var(--text-primary) !important;
    text-align: left !important;
    font-weight: 600;
}

.decision-matrix {
    background: var(--bg-secondary);
    padding: 30px;
    border-radius: 15px;
    border-left: 5px solid var(--accent-primary);
    border: 1px solid var(--border-color);
}

.decision-matrix h3 {
    color: var(--text-primary);
    margin-bottom: 25px;
    text-align: center;
}

.decision-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
}

.decision-card {
    background: var(--bg-card);
    padding: 25px;
    border-radius: 12px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.decision-card h4 {
    color: var(--text-primary);
    margin-bottom: 15px;
    font-size: 1.2rem;
}

.decision-card ul {
    list-style: none;
}

.decision-card li {
    padding: 5px 0;
    padding-left: 20px;
    position: relative;
    color: var(--text-secondary);
}

.decision-card li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--accent-primary);
    font-weight: bold;
}

/* Navigation Grid */
.navigation-content {
    margin-top: 30px;
}

.nav-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    margin-bottom: 40px;
}

.nav-card {
    background: white;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
    border-top: 4px solid #667eea;
    position: relative;
    overflow: hidden;
}

.nav-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.05) 0%, rgba(118, 75, 162, 0.05) 100%);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.nav-card:hover::before {
    opacity: 1;
}

.nav-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
}

.nav-icon {
    font-size: 2.5rem;
    margin-bottom: 15px;
    text-align: center;
}

.nav-card h3 {
    color: var(--text-primary);
    margin-bottom: 15px;
    font-size: 1.4rem;
    text-align: center;
}

.nav-card p {
    color: var(--text-secondary);
    margin-bottom: 20px;
    text-align: center;
    line-height: 1.6;
}

.nav-topics {
    display: flex;
    justify-content: center;
    gap: 8px;
    flex-wrap: wrap;
    margin-bottom: 15px;
}

.nav-topics span {
    background: #f1f5f9;
    color: var(--text-secondary);
    padding: 4px 8px;
    border-radius: 10px;
    font-size: 0.8rem;
    font-weight: 500;
}

.nav-duration {
    text-align: center;
    color: var(--accent-primary);
    font-weight: 600;
    font-size: 0.9rem;
}

.session-tips {
    background: #f8f9fa;
    padding: 30px;
    border-radius: 15px;
    border-left: 5px solid #8b5cf6;
}

.session-tips h3 {
    color: var(--text-primary);
    margin-bottom: 20px;
    text-align: center;
}

.tips-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.tip {
    display: flex;
    align-items: center;
    gap: 10px;
    background: white;
    padding: 15px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.tip i {
    color: var(--accent-secondary);
    font-size: 1.2rem;
}

.tip p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin: 0;
}

/* Hybrid Approaches */
.hybrid-content {
    margin-top: 30px;
}

.frameworks-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
    margin-bottom: 40px;
}

.framework-card {
    background: white;
    padding: 25px;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
    text-align: center;
    border-top: 4px solid #667eea;
}

.framework-logo {
    font-size: 3rem;
    margin-bottom: 15px;
}

.framework-card h4 {
    color: var(--text-primary);
    margin-bottom: 15px;
    font-size: 1.3rem;
}

.framework-card p {
    color: var(--text-secondary);
    margin-bottom: 20px;
    line-height: 1.6;
}

.framework-features {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 8px;
}

.framework-features span {
    background: #f0fff4;
    color: #065f46;
    padding: 4px 8px;
    border-radius: 10px;
    font-size: 0.8rem;
    font-weight: 500;
}

.isr-explanation {
    background: #f8f9fa;
    padding: 30px;
    border-radius: 15px;
    border-left: 5px solid #f59e0b;
}

.isr-explanation h3 {
    color: var(--text-primary);
    margin-bottom: 25px;
    text-align: center;
}

.isr-flow {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.isr-step {
    background: white;
    padding: 20px;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    flex: 1;
    min-width: 200px;
}

.step-number {
    background: #f59e0b;
    color: white;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 10px;
    font-weight: bold;
}

.step-content h4 {
    color: var(--text-primary);
    margin-bottom: 8px;
    font-size: 1.1rem;
}

.step-content p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.4;
}

.isr-arrow {
    font-size: 1.5rem;
    color: #f59e0b;
    font-weight: bold;
}

/* Summary Styles */
.summary-content {
    margin-top: 30px;
}

.takeaways-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    margin-bottom: 40px;
}

.takeaway-card {
    background: white;
    padding: 25px;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
    border-top: 4px solid #667eea;
}

.takeaway-icon {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 15px;
}

.takeaway-card h3 {
    color: var(--text-primary);
    margin-bottom: 15px;
    font-size: 1.3rem;
    text-align: center;
}

.takeaway-card ul {
    list-style: none;
}

.takeaway-card li {
    padding: 6px 0;
    padding-left: 20px;
    position: relative;
    color: var(--text-secondary);
}

.takeaway-card li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--accent-primary);
    font-weight: bold;
}

.next-steps {
    background: #f8f9fa;
    padding: 30px;
    border-radius: 15px;
    border-left: 5px solid #10b981;
    margin-bottom: 30px;
}

.next-steps h3 {
    color: var(--text-primary);
    margin-bottom: 25px;
    text-align: center;
}

.learning-path {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.path-step {
    display: flex;
    align-items: center;
    gap: 20px;
    background: white;
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
}

.step-badge {
    background: #10b981;
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 1.2rem;
    flex-shrink: 0;
}

.step-content h4 {
    color: var(--text-primary);
    margin-bottom: 5px;
    font-size: 1.2rem;
}

.step-content p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.4;
}

.resources {
    background: #f0f8ff;
    padding: 30px;
    border-radius: 15px;
    border-left: 5px solid #3b82f6;
}

.resources h3 {
    color: var(--text-primary);
    margin-bottom: 20px;
    text-align: center;
}

.resources-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 15px;
}

.resource-item {
    display: flex;
    align-items: center;
    gap: 10px;
    background: white;
    padding: 15px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.resource-item i {
    color: #3b82f6;
    font-size: 1.2rem;
}

.resource-item a {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.resource-item a:hover {
    color: #3b82f6;
}

/* Theme Toggle */
.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    border: 2px solid var(--border-color);
    background: var(--bg-card);
    color: var(--text-primary);
    font-size: 1.2rem;
    cursor: pointer;
    transition: all 0.3s ease;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow);
}

.theme-toggle:hover {
    transform: scale(1.1) rotate(180deg);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.2);
}

/* Footer */
.footer {
    text-align: center;
    padding: 30px 0;
    margin-top: 40px;
    border-top: 2px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .presentation-container {
        margin: 10px;
        padding: 15px;
        min-height: calc(100vh - 20px);
    }

    .header h1 {
        font-size: 2.5rem;
    }

    .slide h2 {
        font-size: 2rem;
    }

    .topics-grid,
    .frameworks-grid,
    .takeaways-grid {
        grid-template-columns: 1fr;
    }

    .table-header,
    .table-row {
        grid-template-columns: 1fr;
        gap: 10px;
    }

    .timeline-item {
        flex-direction: column;
        text-align: center;
        gap: 15px;
    }

    .isr-flow {
        flex-direction: column;
    }

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

    .path-step {
        flex-direction: column;
        text-align: center;
        gap: 15px;
    }

    .slide-nav {
        flex-direction: column;
        gap: 15px;
    }

    .slide-nav button {
        width: 100%;
        max-width: 200px;
    }
}