body {
    background-color: #f8f9fa;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

.container {
    max-width: 700px;
}

.card-header h5 {
    font-weight: 500;
}

.btn-primary {
    background-color: #0d6efd;
    border-color: #0d6efd;
}

#thaiResult, #gregorianResult {
    background-color: #e9ecef;
    padding: 1rem;
    border-radius: 0.25rem;
    transition: background-color 0.3s ease;
}

#thaiResult p, #gregorianResult p {
    margin: 0;
}

.form-label {
    font-weight: 500;
}