body {  
    font-family: Arial, sans-serif;  
    display: flex;  
    justify-content: center;  
    align-items: center;  
    height: 100vh;  
    margin: 0;  
    background-color: #f0f0f0;  
}  
  
.container {  
    background-color: #fff;  
    padding: 20px;  
    border-radius: 8px;  
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);  
    text-align: center;  
}  
  
h1 {  
    margin-bottom: 20px;  
}  
  
input, button {  
    padding: 10px;  
    font-size: 16px;  
    margin: 5px;  
}  
  
#result {  
    margin-top: 20px;  
    font-size: 18px;  
}