* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background-color: #f8f9fa;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

.navbar {
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.card {
    border: none;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0,0,0,0.15) !important;
}

.preview-container {
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    overflow: hidden;
}

.btn {
    border-radius: 5px;
    font-weight: 500;
    transition: all 0.3s ease;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}

.form-control, .form-select {
    border-radius: 5px;
    border: 1px solid #ddd;
    transition: border-color 0.3s ease;
}

.form-control:focus, .form-select:focus {
    border-color: #0066cc;
    box-shadow: 0 0 0 0.2rem rgba(0, 102, 204, 0.25);
}

.nav-tabs .nav-link {
    color: #666;
    border: none;
    border-bottom: 3px solid transparent;
    transition: all 0.3s ease;
}

.nav-tabs .nav-link.active {
    color: #0066cc;
    border-bottom: 3px solid #0066cc;
    background: none;
}

.nav-tabs .nav-link:hover {
    color: #0066cc;
    border-bottom: 3px solid #0066cc;
}

/* Responsive Design */
@media (max-width: 768px) {
    .card-body {
        padding: 15px;
    }

    .preview-container {
        min-height: 250px;
    }

    .btn {
        margin-top: 5px;
    }
}

/* Print Styles */
@media print {
    body {
        background: white;
    }

    .navbar, .btn, .card-header {
        display: none;
    }

    .preview-container {
        box-shadow: none;
    }
}

/* Loading Animation */
.spinner {
    border: 3px solid #f3f3f3;
    border-top: 3px solid #0066cc;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Input validation */
.form-control.is-invalid {
    border-color: #dc3545;
}

.form-control.is-valid {
    border-color: #28a745;
}

/* Color scheme */
:root {
    --primary-color: #0066cc;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --light-bg: #f8f9fa;
    --text-dark: #333;
    --text-muted: #6c757d;
}