I've tried refreshing... still is like that

Since we allow html and css in posts, you can break the layout if there are problems with html in your message. Our html purifier fixes some of the issues like unclosed tags, but it can't fix all of the problems, and it can't do anything with css which is technically valid but produces a visually corrupted layout. You'll need to check your post in html mode and edit it manually so it doesn't break anything near it.