.related_posts_by_tag_widget.widget li {
    margin: 5px 0;
    color: black;
}

.related_posts_by_tag_widget.widget li a {
    display: block;
    border-bottom: 1px solid rgba(167, 167, 167, 0.15);
}

.related_posts_by_tag_widget.widget li a:hover {
    border-color: initial;
}