/**
 * User area shared styles (Lego AI Shop).
 * Header sticky: giữ thanh header (topbar + navbar) khi cuộn trên listProduct, detailsProduct, giỏ hàng.
 */
.user-header-sticky {
    position: sticky;
    top: 0;
    z-index: 1030;
    background: #fff;
}