body {
    background-color: #f8f9fa;
    font-family: Arial, sans-serif;
}

.container {
    margin-top: 50px;
    max-width: 600px;
}

.calculator-box {
    background: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0px 0px 15px rgba(0, 0, 0, 0.1);
}

h2 {
    color: #007bff;
}

button {
    width: 100%;
}