.proforma-calculator {
    max-width: 1200px;
    margin: 20px auto;
    font-family: Arial, sans-serif;
}

.calculator-nav ul {
    list-style: none;
    padding: 0;
    display: flex;
    background: #f4f4f4;
    border-bottom: 1px solid #ddd;
}

.calculator-nav li a {
    padding: 10px 20px;
    display: block;
    text-decoration: none;
    color: #333;
}

.calculator-nav li a.active {
    background: #007bff;
    color: white;
}

.calculator-content {
    padding: 20px;
    background: #fff;
    border: 1px solid #ddd;
    border-radius: 5px;
}

.section {
    margin-bottom: 20px;
}

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

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

input[type="text"], input[type="number"] {
    padding: 8px;
    width: 200px;
    border: 1px solid #ccc;
    border-radius: 4px;
}

table {
    width: 100%;
    border-collapse: collapse;
}

th, td {
    padding: 10px;
    border: 1px solid #ddd;
    text-align: left;
}

.calculator-footer {
    margin-top: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

button {
    padding: 10px 20px;
    background: #007bff;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

button:hover {
    background: #0056b3;
}

#results {
    padding: 10px;
}