/* CSS */
.calculator {
    max-width: 400px;
    margin: auto;
    padding: 20px;
    background-color: #ffffff;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    border-radius: 10px;
}

.calculator h2 {
    text-align: center;
    color: #333;
}

.form-group {
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
}

.form-group input, .form-group select {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
}

.output {
    margin-top: 20px;
    padding: 10px;
    background-color: #e6f7e6;
    border: 1px solid #bde0bd;
    border-radius: 5px;
}

.progress-bar {
    margin-top: 10px;
    width: 100%;
    background-color: #ddd;
    height: 20px;
    border-radius: 10px;
    overflow: hidden;
}

.progress-bar-inner {
    height: 100%;
    width: 0%;
    background-color: #4caf50;
    text-align: center;
    color: white;
    line-height: 20px;
    font-size: 12px;
}