<style>
    body {
        font-family: Arial, sans-serif;
        line-height: 1.6;
        margin: 0;
        padding: 0;
        background-color: #f4f4f4;
    }

    .container {
        width: 80%;
        margin: auto;
        overflow: hidden;
        padding: 20px;
        background-color: #fff;
        box-shadow: 0 0 10px rgba(0,0,0,0.1);
        border-radius: 5px;
        margin-top: 20px;
    }

    h1 {
        color: #333;
        text-align: center;
    }

    form {
        display: flex;
        flex-direction: column;
    }

    label {
        margin-top: 10px;
    }

    input, select {
        padding: 8px;
        margin-top: 5px;
    }

    button {
        background-color: #4CAF50;
        color: white;
        padding: 10px;
        border: none;
        cursor: pointer;
        margin-top: 20px;
    }

    button:hover {
        background-color: #45a049;
    }

    #result {
        margin-top: 20px;
        border-top: 1px solid #ddd;
        padding-top: 20px;
    }

    .hidden {
        display: none;
    }
</style>