body {
    background-color: #f8f9fa;
}

.container {
    max-width: 1200px;
}

.card {
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.1);
    border: none;
    border-radius: 10px;
}

.table {
    margin-bottom: 0;
}

.table th, .table td {
    vertical-align: middle;
}

.table thead th {
    background-color: #f8f9fa;
    border-bottom: 2px solid #dee2e6;
}

.table tbody tr:hover {
    background-color: #f5f5f5;
}

.btn {
    border-radius: 5px;
    padding: 8px 20px;
}

.form-control, .form-select {
    border-radius: 5px;
    padding: 8px 12px;
}

.form-control:focus, .form-select:focus {
    box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
    border-color: #80bdff;
}

#previewArea {
    max-height: 500px;
    overflow-y: auto;
}

.selected-row {
    background-color: #e3f2fd !important;
}

@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    .btn {
        width: 100%;
        margin-bottom: 10px;
    }
}