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

.card {
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s;
}

.card:hover {
    transform: translateY(-5px);
}

.invoice-container {
    background-color: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
    max-width: 800px;
    margin: 0 auto;
}

.table-responsive {
    overflow-x: auto;
}

@media (max-width: 768px) {
    .navbar-nav {
        margin-top: 10px;
    }
    
    .btn-block-mobile {
        display: block;
        width: 100%;
        margin-bottom: 10px;
    }
}