body { 
    font-family: Arial, sans-serif; 
    margin: 0;
    padding: 0;
    background: #f5f5f5;
}
.container { 
    max-width: 1600px; 
    margin: 0 auto;
    padding: 20px;
}
.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 30px;
    border-radius: 8px;
    margin-bottom: 20px;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}
.header h1 {
    margin: 0;
    font-size: 28px;
}
.header p {
    margin: 10px 0 0 0;
    opacity: 0.9;
}
.chart-container { 
    background-color: white; 
    border-radius: 8px; 
    padding: 20px; 
    margin-bottom: 20px; 
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    min-height: 500px;
}
.chart-container h2 {
    color: #333;
    margin-top: 0;
    border-bottom: 2px solid #667eea;
    padding-bottom: 10px;
}
.loading {
    text-align: center;
    padding: 40px;
    color: #666;
}
.loading-spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #667eea;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 20px auto;
}
@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}
.error {
    text-align: center;
    padding: 40px;
    color: #dc3545;
}
.error-icon {
    font-size: 48px;
    margin-bottom: 10px;
}
.chart-image {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 10px auto;
    border-radius: 4px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}
.nav-links {
    text-align: center;
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid #eee;
}
.nav-links a {
    display: inline-block;
    margin: 0 10px;
    padding: 12px 24px;
    background: #667eea;
    color: white;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 500;
    transition: background 0.3s;
}
.nav-links a:hover {
    background: #5568d3;
}
.description {
    background-color: #f8f9fa;
    border-left: 4px solid #667eea;
    padding: 15px;
    margin: 15px 0;
    border-radius: 4px;
    font-size: 14px;
    color: #555;
}