.gst-calculator {
    max-width: 500px;
    margin: 20px auto;
    padding: 25px;
    background: #f8f9fa;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0,0,0,0.1);
}

.calculator-header {
    text-align: center;
    margin-bottom: 25px;
}

.calculator-header h3 {
    color: #2c3e50;
    margin: 0;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: #34495e;
    font-weight: 600;
}

.form-control {
    width: 100%;
    padding: 10px;
    border: 2px solid #e0e0e0;
    border-radius: 5px;
    font-size: 16px;
    transition: border-color 0.3s ease;
}

.form-control:focus {
    border-color: #3498db;
    outline: none;
}

.btn-calculate {
    width: 100%;
    padding: 12px;
    background: #3498db;
    color: white;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    cursor: pointer;
    transition: background 0.3s ease;
}

.btn-calculate:hover {
    background: #2980b9;
}

.results {
    margin-top: 25px;
    padding: 15px;
    background: white;
    border-radius: 5px;
}

.result-item {
    display: flex;
    justify-content: space-between;
    margin: 10px 0;
    padding: 10px;
    background: #f8f9fa;
    border-radius: 5px;
}

.result-item span:first-child {
    color: #7f8c8d;
}

.result-value {
    color: #2c3e50;
    font-weight: bold;
}