body { 
    background: #f4f4f4; 
    font-family: Arial, sans-serif; 
}

.container { 
    max-width: 400px; 
    margin: 40px auto; 
    background: #fff; 
    border-radius: 8px; 
    box-shadow: 0 2px 8px rgba(0,0,0,0.1); 
    padding: 32px; 
}

#speedometer { 
    display: block; 
    margin: 0 auto; 
}