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

:root {
    --primary-color: #2563eb;
    --secondary-color: #3b82f6;
    --failure-color: #ef4444;
    --warning-color: #f59e0b;
    --success-color: #10b981;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-color: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 40px 0;
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

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

.main-nav {
    background: var(--card-bg);
    padding: 15px 0;
    box-shadow: var(--shadow);
}

.main-nav .container {
    display: flex;
    gap: 20px;
    justify-content: center;
}

.nav-link {
    padding: 10px 24px;
    border-radius: 25px;
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    transition: all 0.3s ease;
    font-size: 1rem;
}

.nav-link:hover {
    background: #f1f5f9;
    color: var(--primary-color);
}

.nav-link.active {
    background: var(--primary-color);
    color: white;
}

.filter-nav {
    background: var(--card-bg);
    padding: 20px 0;
    border-bottom: 1px solid var(--border-color);
}

.filter-nav .container {
    display: flex;
    gap: 30px;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
}

.filter-group {
    display: flex;
    gap: 10px;
    align-items: center;
}

.filter-label {
    color: var(--text-secondary);
    font-weight: 500;
}

.filter-btn {
    padding: 8px 18px;
    border: 2px solid var(--border-color);
    background: var(--card-bg);
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: 500;
    transition: all 0.3s ease;
}

.filter-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.filter-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.category-select {
    padding: 8px 16px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 0.95rem;
    background: white;
    cursor: pointer;
    min-width: 150px;
}

.category-select:focus {
    outline: none;
    border-color: var(--primary-color);
}

main {
    padding: 40px 0;
}

.category-stats {
    margin-bottom: 40px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
}

.stat-card {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 24px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

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

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-top: 8px;
}

.cases-grid {
    margin-top: 40px;
}

.cases-list {
    display: grid;
    gap: 24px;
}

.case-card {
    background: var(--card-bg);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: pointer;
    border-top: 4px solid var(--primary-color);
}

.case-card.result-failure {
    border-top-color: var(--failure-color);
}

.case-card.result-warning {
    border-top-color: var(--warning-color);
}

.case-card.result-success {
    border-top-color: var(--success-color);
}

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

.case-header {
    padding: 24px;
    border-bottom: 1px solid var(--border-color);
}

.case-category {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 15px;
    font-size: 0.85rem;
    font-weight: 500;
    margin-bottom: 12px;
    background: #e0e7ff;
    color: #3730a3;
}

.case-title {
    font-size: 1.4rem;
    margin-bottom: 12px;
    color: var(--text-color);
}

.case-meta {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    align-items: center;
}

.result-badge {
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
}

.result-badge.failure {
    background: #fee2e2;
    color: #dc2626;
}

.result-badge.warning {
    background: #fef3c7;
    color: #d97706;
}

.case-location {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.case-body {
    padding: 24px;
}

.case-summary {
    color: var(--text-secondary);
    margin-bottom: 16px;
    font-size: 1.05rem;
}

.key-points {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 16px;
}

.key-point {
    background: #f1f5f9;
    padding: 6px 14px;
    border-radius: 6px;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.tag {
    background: #e0f2fe;
    color: #0369a1;
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 0.8rem;
}

footer {
    background: var(--text-color);
    color: white;
    text-align: center;
    padding: 30px 0;
    margin-top: 60px;
}

footer p {
    opacity: 0.8;
}

.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    overflow-y: auto;
}

.modal.show {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding: 20px;
}

.modal-content {
    background: white;
    border-radius: 16px;
    max-width: 800px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    animation: slideUp 0.3s ease;
}

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

.modal-header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 24px;
    position: sticky;
    top: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h3 {
    font-size: 1.5rem;
    padding-right: 40px;
}

.close-btn {
    background: transparent;
    border: none;
    color: white;
    font-size: 2rem;
    cursor: pointer;
    line-height: 1;
    transition: opacity 0.3s;
}

.close-btn:hover {
    opacity: 0.8;
}

.modal-body {
    padding: 30px;
}

.modal-section {
    margin-bottom: 24px;
}

.modal-section h4 {
    color: var(--primary-color);
    margin-bottom: 12px;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

.modal-section p {
    color: var(--text-secondary);
    line-height: 1.8;
}

.modal-section ul {
    padding-left: 20px;
    color: var(--text-secondary);
}

.modal-section li {
    margin-bottom: 8px;
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 16px;
    margin-bottom: 24px;
}

.info-item {
    background: #f8fafc;
    padding: 16px;
    border-radius: 10px;
}

.info-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

.info-value {
    font-weight: 600;
    color: var(--text-color);
}

.reflection-box {
    background: #f0fdf4;
    border-left: 4px solid var(--success-color);
    padding: 20px;
    border-radius: 8px;
}

.reflection-box h4 {
    color: #166534;
}

.hidden {
    display: none !important;
}

.summary-page {
    padding-top: 40px;
}

.core-summary {
    margin-bottom: 50px;
}

.core-summary-box {
    background: linear-gradient(135deg, #fef3c7, #fde68a);
    border-radius: 20px;
    padding: 40px;
    text-align: center;
    box-shadow: var(--shadow-lg);
}

.core-summary-box h2 {
    color: #92400e;
    margin-bottom: 20px;
    font-size: 1.8rem;
}

.core-quote {
    font-size: 1.3rem;
    color: #78350f;
    margin-bottom: 24px;
    line-height: 1.8;
}

.core-quote strong {
    color: #92400e;
}

.formula {
    background: white;
    padding: 24px;
    border-radius: 12px;
    margin-top: 20px;
}

.formula p:first-child {
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 12px;
}

.formula p:last-child {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.8;
}

.knowledge-section {
    margin-bottom: 60px;
}

.section-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 30px;
    padding-bottom: 16px;
    border-bottom: 2px solid var(--border-color);
}

.section-number {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    font-weight: 700;
    flex-shrink: 0;
}

.section-number.danger {
    background: linear-gradient(135deg, #ef4444, #dc2626);
}

.section-number.success {
    background: linear-gradient(135deg, #10b981, #059669);
}

.section-header h2 {
    font-size: 1.6rem;
    color: var(--text-color);
}

.knowledge-cards {
    display: grid;
    gap: 20px;
}

.knowledge-card {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 28px;
    box-shadow: var(--shadow);
    border-left: 4px solid var(--primary-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.knowledge-card:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow-lg);
}

.knowledge-card.danger {
    border-left-color: var(--failure-color);
}

.knowledge-card.success {
    border-left-color: var(--success-color);
}

.knowledge-card h4 {
    color: var(--primary-color);
    margin-bottom: 12px;
    font-size: 1.15rem;
}

.knowledge-card.danger h4 {
    color: var(--failure-color);
}

.knowledge-card.success h4 {
    color: var(--success-color);
}

.knowledge-card p {
    color: var(--text-secondary);
    line-height: 1.8;
    font-size: 1rem;
}

@media (max-width: 768px) {
    header h1 {
        font-size: 1.8rem;
    }
    
    .subtitle {
        font-size: 1rem;
    }
    
    .main-nav .container {
        gap: 10px;
    }
    
    .nav-link {
        padding: 8px 16px;
        font-size: 0.9rem;
    }
    
    .filter-nav .container {
        flex-direction: column;
        gap: 15px;
    }
    
    .filter-group {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .filter-btn {
        padding: 6px 14px;
        font-size: 0.9rem;
    }
    
    .case-header,
    .case-body {
        padding: 16px;
    }
    
    .case-title {
        font-size: 1.2rem;
    }
    
    .case-meta {
        gap: 10px;
    }
    
    .modal-content {
        border-radius: 12px;
    }
    
    .modal-header {
        padding: 20px;
    }
    
    .modal-header h3 {
        font-size: 1.2rem;
    }
    
    .modal-body {
        padding: 20px;
    }
    
    .info-grid {
        grid-template-columns: 1fr;
    }
    
    .core-summary-box {
        padding: 24px;
    }
    
    .core-summary-box h2 {
        font-size: 1.4rem;
    }
    
    .core-quote {
        font-size: 1.1rem;
    }
    
    .section-header {
        flex-direction: column;
        text-align: center;
    }
    
    .section-header h2 {
        font-size: 1.3rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 12px;
    }
    
    header {
        padding: 30px 0;
    }
    
    .stat-number {
        font-size: 2rem;
    }
}