:root {
    --primary-color: #3498db;
    --background-color: #f4f6f8;
    --card-background: #ffffff;
    --text-color: #2c3e50;
    --border-radius: 8px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: var(--card-background);
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

header {
    text-align: center;
    margin-bottom: 30px;
}

h1 {
    font-size: 24px;
    margin-bottom: 10px;
}

.controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
    margin-bottom: 20px;
    padding: 15px;
    background: #f8f9fa;
    border-radius: var(--border-radius);
}

.metric-selector .btn-group {
    display: inline-flex;
    gap: 10px;
}

.btn {
    padding: 8px 16px;
    border: 1px solid #ddd;
    background: white;
    cursor: pointer;
    border-radius: 4px;
    transition: all 0.2s;
}

.btn:hover {
    background: #eee;
}

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

.zip-toggles {
    display: flex;
    gap: 15px;
    align-items: center;
}

.zip-toggle-label {
    display: flex;
    align-items: center;
    gap: 5px;
    cursor: pointer;
    background: white;
    padding: 5px 10px;
    border-radius: 4px;
    border: 1px solid #eee;
}

.chart-container {
    position: relative;
    height: 500px;
    width: 100%;
}

footer {
    text-align: center;
    margin-top: 30px;
    color: #666;
    font-size: 12px;
}