Currently, if you edit a blog post and enter text that is longer than the width of the Full Article box (e.g. a long URL), the box will expand horizontally. However, this box is contained in a window that does not expand horizontally and no horizontal scroll bars appear, so you will have a difficult time navigating the window.

Instead, please visually wrap long text to a new line. This is actually the behaviour of Full Article box when you create a blog post.