#catalog-left.is-loading .fade-wrap {
    opacity: .55;
    transform: translateY(2px);
    transition: opacity .18s ease, transform .18s ease;
}

#catalog-left .fade-in {
    animation: fadeScale .18s cubic-bezier(.2,.7,.3,1) both;
}

@keyframes fadeScale {
    from {
        opacity: 0;
        transform: translateY(2px) scale(.99); /* giảm từ 4px xuống 2px, scale nhẹ hơn */
    }

    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}