Styles update

Author: vhuseinova-msft

packages/react-components/src/components/styles/MessageThread.styles.ts

@@ -208,7 +208,7 @@ export const useChatMyMessageStyles = makeStyles({
     boxShadow: tokens.shadow4,
     backgroundColor: tokens.colorNeutralBackground1,
     position: 'absolute',
-    top: '-18px',
+    top: '-19px',
     right: '0',
     ...shorthands.borderRadius(tokens.borderRadiusMedium),
     zIndex: 1,