.wp-block-separator {
    border-top: 1px solid var(--wp--preset--color--noir);
}

.wp-block-column .wp-block-separator {
    opacity: 0.3;
    width: 80%;
    display: block;
    margin-left: 0;
}

.wp-block-column .wp-block-separator.is-style-wide {
    width: 100%;
    opacity: 0.7;
}