body {
    font-family: Arial, sans-serif;
    background: #f7f7f7;
    padding: 20px;
}

.box {
    max-width: 400px;
    margin: auto;
    background: white;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}

input {
    width: 100%;
    padding: 10px;
    margin: 10px 0;
    border-radius: 5px;
    border: 1px solid #aaa;
}

button {
    width: 100%;
    padding: 10px;
    background: black;
    color: white;
    border: none;
    border-radius: 5px;
    font-size: 16px;
}

#result {
    margin-top: 15px;
    font-size: 16px;
}