/* Responsive styles for mobile and tablet */
@media (max-width: 968px) {
    .app-container {
        grid-template-columns: 1fr;
    }

    .sidebar {
        transform: translateX(-100%);
    }

    .sidebar.mobile-open {
        transform: translateX(0);
    }

    .main-content {
        margin-left: 0;
        width: 100%;
    }

    .mobile-menu-toggle {
        display: block;
    }

    .stats-grid {
        grid-template-columns: 1fr 1fr;
    }

    .books-grid {
        grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    }

    .book-detail-grid {
        grid-template-columns: 1fr;
    }

    .content-area {
        padding: 20px;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    table {
        font-size: 12px;
    }

    th, td {
        padding: 8px;
    }
}

@media (max-width: 480px) {
    .stats-grid {
        grid-template-columns: 1fr;
    }

    .books-grid {
        grid-template-columns: 1fr;
    }

    .login-box {
        padding: 30px 20px;
    }

    .content-area {
        padding: 15px;
    }

    .section {
        padding: 16px;
        margin-bottom: 16px;
    }

    .book-detail-actions {
        flex-direction: column;
    }

    .book-detail-actions .btn {
        width: 100%;
    }

    .modal-full {
        max-width: 100vw;
        height: 100vh;
        max-height: 100vh;
        border-radius: 0;
    }

    .document-viewer-body {
        height: calc(100vh - 140px);
    }
}