The .row CSS selector is no longer utilized in the structure for generating the forum post container. Certain CSS rules referencing the .row selector within the mod/forum/styles.css file require updates.

The .row classes were removed in MDL-75669.

Since the .row CSS selector isn't used in the structure for generating the forum post container, some forum-specific CSS rules are no longer being applied, such as this one reported in MDL-85311:

/* Forumpost unread

-------------------------*/

.forumpost.unread .row.header,

.path-course-view .unread,

span.unread {

    background-color: #ffd;

}

.forumpost.unread .row.header {

    border-bottom: 1px solid #ddd;

}

It would be good to review the other  .forumpost .row CSS rules to check other parts of the forum UI aren't affected.