.gst-calc {
    max-width: 500px;
    margin: 20px auto;
    padding: 25px;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    font-family: Arial, sans-serif;
}

.gst-calc h3 {
    color: #2c3e50;
    text-align: center;
    margin-bottom: 20px;
    font-size: 22px;
}

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

.gst-form label {
    display: block;
    margin-bottom: 5px;
    font-weight: 600;
    color: #34495e;
}

.gst-form .form-control {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
}

.gst-btn {
    width: 100%;
    padding: 12px;
    background: #3498db;
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 16px;
    cursor: pointer;
    margin-top: 10px;
}

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

.gst-results {
    margin-top: 20px;
    padding: 15px;
    background: #f8f9fa;
    border-radius: 4px;
    display: none;
}

.result-row {
    display: flex;
    justify-content: space-between;
    padding: 8px 0;
    border-bottom: 1px dashed #ddd;
}

.result-row:last-child {
    border-bottom: none;
}

.total-row {
    font-weight: bold;
    margin-top: 10px;
    padding-top: 10px;
    border-top: 2px solid #3498db;
}

@media (max-width: 600px) {
    .gst-calc {
        padding: 15px;
        margin: 15px;
    }
}