/* Chapter 2 Specific Styles */
    .model-demo {
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    border: 2px solid #0ea5e9;
    border-radius: 12px;
    padding: 2rem;
    margin: 2rem 0;
    position: relative;
    }

    .model-demo::before {
    content: "Interactive Model Demo";
    position: absolute;
    top: -12px;
    left: 20px;
    background: #0ea5e9;
    color: white;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: bold;
    }

    .parameter-controls {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin: 1.5rem 0;
    }

    .parameter-control {
    background: white;
    padding: 1rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    }

    .parameter-control label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #334155;
    }

    .parameter-control input[type="range"] {
    width: 100%;
    margin: 0.5rem 0;
    }

    .parameter-value {
    display: inline-block;
    background: #0ea5e9;
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.9rem;
    font-weight: bold;
    margin-left: 0.5rem;
    }

    .visualization-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin: 2rem 0;
    align-items: start;
    }

    .chart-container {
    background: white;
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    text-align: center;
    }

    .chart-container h4 {
    color: #1e40af;
    margin-bottom: 1rem;
    font-size: 1.2rem;
    }

    .chart-placeholder {
    width: 100%;
    height: 300px;
    background: linear-gradient(135deg, #f1f5f9 0%, #e2e8f0 100%);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #64748b;
    font-weight: 500;
    margin: 1rem 0;
    position: relative;
    overflow: hidden;
    }

    .chart-image {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: 8px;
    }

    .problem-highlight {
    background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
    border-left: 4px solid #f59e0b;
    padding: 1.5rem;
    border-radius: 8px;
    margin: 1.5rem 0;
    position: relative;
    }

    .problem-highlight::before {
    content: "⚠️ Problem Identified";
    position: absolute;
    top: -12px;
    left: 20px;
    background: #f59e0b;
    color: white;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: bold;
    }

    .model-comparison {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
    }

    .model-card {
    background: white;
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
    border: 2px solid transparent;
    }

    .model-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
    }

    .model-card.linear {
    border-color: #10b981;
    }

    .model-card.tree {
    border-color: #f59e0b;
    }

    .model-card h4 {
    color: #1f2937;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    }

    .pros-cons-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin: 1rem 0;
    }

    .pros, .cons {
    padding: 1rem;
    border-radius: 8px;
    }

    .pros {
    background: linear-gradient(135deg, #ecfdf5 0%, #d1fae5 100%);
    border: 1px solid #10b981;
    }

    .cons {
    background: linear-gradient(135deg, #fef2f2 0%, #fecaca 100%);
    border: 1px solid #ef4444;
    }

    .pros h5 {
    color: #065f46;
    margin-bottom: 0.5rem;
    }

    .cons h5 {
    color: #991b1b;
    margin-bottom: 0.5rem;
    }

    .metric-display {
    display: flex;
    justify-content: space-around;
    margin: 1rem 0;
    padding: 1rem;
    background: #f8fafc;
    border-radius: 8px;
    }

    .metric {
    text-align: center;
    }

    .metric-value {
    font-size: 1.5rem;
    font-weight: bold;
    color: #1e40af;
    }

    .metric-label {
    font-size: 0.9rem;
    color: #64748b;
    }

    .overfitting-demo {
    position: relative;
    margin: 2rem 0;
    }

    .complexity-slider {
    width: 100%;
    margin: 1rem 0;
    }

    .dataset-selector {
    display: flex;
    gap: 1rem;
    margin: 1rem 0;
    flex-wrap: wrap;
    }

    .dataset-btn {
    padding: 0.5rem 1rem;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    background: white;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
    }

    .dataset-btn:hover, .dataset-btn.active {
    border-color: #0ea5e9;
    background: #0ea5e9;
    color: white;
    }

@media (max-width: 768px) {
    .visualization-container {
    grid-template-columns: 1fr;
    gap: 1rem;
    }

    .parameter-controls {
    grid-template-columns: 1fr;
    }

    .model-comparison {
    grid-template-columns: 1fr;
    }

    .pros-cons-grid {
    grid-template-columns: 1fr;
    }   
}