body {
    font-family: Arial, sans-serif;
    background-color: #333;
    text-align: center;
    color: white;
}
.container {
    background-color: #444;
    padding: 20px;
    width: 300px;
    margin: 50px auto;
    border-radius: 10px;
    box-shadow: 0px 0px 10px rgba(0, 0, 0, 0.5);
}
h2 {
    background-color: #28a745;
    padding: 10px;
    border-radius: 5px;
}
label, select, input {
    display: block;
    width: 100%;
    margin: 10px 0;
}
button {
    width: 48%;
    padding: 10px;
    margin: 5px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}
.calculate-btn {
    background-color: #007bff;
    color: white;
}
.clear-btn {
    background-color: #dc3545;
    color: white;
}