Search pane in a separate window?

Until today when I did a text search/replace a separate floating window would open on top of my edit window. Starting today the search/replace UI elements appear in a pane that is pinned to the top of the edit window. Everything in that pane is in a much smaller font than my edit window text; I feel like when it was in its own window it was in a legible font size. So now search/replace has become an eye-straining activity.

How can I get the separate window back? I have searched all over the documentation and the preferences and have not found this.