Little update!
Desktop
// Topic Owner
.topic-post.topic-owner article:not(#post_1) .row .topic-body .topic-meta-data .names::after {
content: "Author";
color: var(--secondary);
font-weight: bold;
background: var(--secondary-medium);
padding: 0px 8px;
border-radius: 8px;
line-height: normal;
}
Mobile
// Topic Owner
.topic-post.topic-owner article:not(#post_1) .row .topic-body .topic-meta-data .names .first:after {
content: 'Author';
color: var(--secondary);
background: var(--secondary-medium);
margin-left: 4px;
padding: 0px 8px;
border-radius: 6px;
line-height: normal;
}