Highlight newly added replies in thread view (#36237)

app/javascript/mastodon/components/status.jsx

@@ -118,6 +118,7 @@ class Status extends ImmutablePureComponent {
     unread: PropTypes.bool,
     showThread: PropTypes.bool,
     isQuotedPost: PropTypes.bool,
+    shouldHighlightOnMount: PropTypes.bool, 
     getScrollPosition: PropTypes.func,
     updateScrollBottom: PropTypes.func,
     cacheMediaWidth: PropTypes.func,
@@ -567,6 +568,7 @@ class Status extends ImmutablePureComponent {
                 'status--first-in-thread': previousId && (!connectUp || connectToRoot), muted: this.props.muted,
                 'status--is-quote': isQuotedPost,
                 'status--has-quote': !!status.get('quote'),
+                'status--highlighted-entry': this.props.shouldHighlightOnMount,
               })
             }
             data-id={status.get('id')}