.wp-block-navigation ul li.current-menu-item > a {
    color: var(--wp--preset--color--secondary);
}
.wp-block-cover-image, .wp-block-cover {
    z-index: 8;
}


 .wp-block-navigation:not(.has-background) .wp-block-navigation__submenu-container {
    z-index: 999;
}