body {
    background: #0f172a;
    font-family: Arial, sans-serif;
    color: white;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.box {
    background: #111827;
    padding: 25px;
    border-radius: 10px;
    width: 320px;
    text-align: center;
}

select, input, button {
    width: 100%;
    padding: 10px;
    margin-top: 10px;
    border-radius: 6px;
    border: none;
}

button {
    background: #22c55e;
    font-weight: bold;
    cursor: pointer;
}

#result {
    margin-top: 15px;
}