body {
    margin: 0;
    padding: 20px;
    font-family: Arial, sans-serif;
    background: #f0f0f0;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    background: white;
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

h1 {
    text-align: center;
    color: #333;
    margin-bottom: 20px;
}

#traffic-canvas {
    border: 2px solid #ddd;
    border-radius: 8px;
    display: block;
    margin: 0 auto 20px;
    background: #e8f5e8;
}

.controls {
    text-align: center;
}

button {
    background: #4CAF50;
    border: none;
    color: white;
    padding: 10px 20px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 16px;
    margin: 4px 8px;
    cursor: pointer;
    border-radius: 4px;
}

button:hover {
    background: #45a049;
}

.info {
    margin-top: 20px;
    text-align: center;
    color: #666;
}

.stats {
    margin-top: 10px;
    text-align: center;
    font-family: monospace;
    background: #f8f9fa;
    padding: 10px;
    border-radius: 5px;
}

.stage-controls {
    text-align: center;
    margin-bottom: 20px;
}

.toolbox {
    background: #fff;
    padding: 10px;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    display: flex;
    gap: 10px;
    justify-content: center;
    margin-bottom: 20px;
}

.toolbox button {
    background: #f8f9fa;
    color: #333;
    border: 1px solid #ddd;
    width: 120px;
}

.toolbox button.active {
    background: #e9ecef;
    border-color: #3498db;
    color: #3498db;
    font-weight: bold;
}

.contribution-info {
    margin-top: 20px;
    padding: 10px;
    background-color: #f9f9f9;
    border: 1px solid #ddd;
    text-align: center;
    font-size: 0.9em;
    border-radius: 5px;
}