body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background-color: #f4f4f4;
    color: #333;
}

.calculator-container {
    /* @tweakable Background color of the calculator container */
    background-color: #ffffff;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    text-align: center;
    width: 90%;
    max-width: 500px;
}

h1 {
    color: #0056b3;
    margin-bottom: 25px;
    font-size: 1.8em;
}

.input-group {
    margin-bottom: 20px;
    text-align: left;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: bold;
    color: #555;
}

input[type="number"],
select {
    width: calc(100% - 20px);
    padding: 10px;
    margin-top: 5px;
    border: 1px solid #ccc;
    border-radius: 5px;
    font-size: 1em;
}

button {
    background-color: #28a745;
    color: white;
    padding: 12px 25px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1.1em;
    font-weight: bold;
    transition: background-color 0.2s ease;
}

button:hover {
    background-color: #218838;
}

.result-area {
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid #eee;
}

.result-area h2 {
    color: #0056b3;
    margin-bottom: 10px;
    font-size: 1.5em;
}

#result-display {
    font-size: 1.6em;
    font-weight: bold;
    color: #007bff;
    word-wrap: break-word;
}